A snapshot a day keeps the bugs away! 📷🐛 (OS: ubuntu)

src/clientSideScene/ClientSideSceneComp.tsx

@@ -5,7 +5,7 @@ import { cameraMouseDragGuards } from 'lib/cameraControls'
 import { useSettingsAuthContext } from 'hooks/useSettingsAuthContext'
 import { ARROWHEAD, DEBUG_SHOW_BOTH_SCENES } from './sceneInfra'
 import { ReactCameraProperties } from './CameraControls'
-import { throttle } from 'lib/utils'
+import { isArray, throttle } from 'lib/utils'
 import {
   sceneInfra,
   kclManager,
@@ -20,13 +20,17 @@ import {
   getParentGroup,
 } from './sceneEntities'
 import { SegmentOverlay, SketchDetails } from 'machines/modelingMachine'
-import { findUsesOfTagInPipe, getNodeFromPath } from 'lang/queryAst'
+import {
+  expectNodeOnPath,
+  findUsesOfTagInPipe,
+  getLastNodeFromPath,
+  getNodeFromPath,
+} from 'lang/queryAst'
 import {
   CallExpression,
   PathToNode,
   Program,
   SourceRange,
-  Value,
   parse,
   recast,
 } from 'lang/wasm'
@@ -186,13 +190,12 @@ const Overlay = ({
   let xAlignment = overlay.angle < 0 ? '0%' : '-100%'
   let yAlignment = overlay.angle < -90 || overlay.angle >= 90 ? '0%' : '-100%'
 
-  const _node1 = getNodeFromPath<CallExpression>(
+  const callExpression = expectNodeOnPath<CallExpression>(
     kclManager.ast,
     overlay.pathToNode,
     'CallExpression'
   )
-  if (err(_node1)) return
-  const callExpression = _node1.node
+  if (err(callExpression)) return
 
   const constraints = getConstraintInfo(
     callExpression,
@@ -549,13 +552,13 @@ const ConstraintSymbol = ({
     varNameMap[_type as LineInputsType]?.implicitConstraintDesc
 
   const _node = useMemo(
-    () => getNodeFromPath<Value>(kclManager.ast, pathToNode),
+    () => getLastNodeFromPath(kclManager.ast, pathToNode),
     [kclManager.ast, pathToNode]
   )
   if (err(_node)) return
   const node = _node.node
 
-  const range: SourceRange = node ? [node.start, node.end] : [0, 0]
+  const range: SourceRange = !isArray(node) ? [node.start, node.end] : [0, 0]
 
   if (_type === 'intersectionTag') return null
 

src/clientSideScene/sceneEntities.ts

@@ -61,7 +61,12 @@ import {
   codeManager,
   editorManager,
 } from 'lib/singletons'
-import { getNodeFromPath, getNodePathFromSourceRange } from 'lang/queryAst'
+import {
+  isNodeType,
+  expectNodeOnPath,
+  getNodeFromPath,
+  getNodePathFromSourceRange,
+} from 'lang/queryAst'
 import { executeAst } from 'lang/langHelpers'
 import {
   createArcGeometry,
@@ -77,7 +82,13 @@ import {
   changeSketchArguments,
   updateStartProfileAtArgs,
 } from 'lang/std/sketch'
-import { isOverlap, normaliseAngle, roundOff, throttle } from 'lib/utils'
+import {
+  isArray,
+  isOverlap,
+  normaliseAngle,
+  roundOff,
+  throttle,
+} from 'lib/utils'
 import {
   addStartProfileAt,
   createArrayExpression,
@@ -463,13 +474,18 @@ export class SceneEntities {
       )
 
       let seg: Group
-      const _node1 = getNodeFromPath<CallExpression>(
+      const callExp = getNodeFromPath<CallExpression>(
         maybeModdedAst,
         segPathToNode,
         'CallExpression'
       )
-      if (err(_node1)) return
-      const callExpName = _node1.node?.callee?.name
+      if (err(callExp)) return
+      const callExpName = isNodeType<CallExpression>(
+        callExp.node,
+        'CallExpression'
+      )
+        ? callExp.node.callee.name
+        : ''
 
       if (segment.type === 'TangentialArcTo') {
         seg = tangentialArcToSegment({
@@ -590,8 +606,12 @@ export class SceneEntities {
       'VariableDeclaration'
     )
     if (trap(_node1)) return Promise.reject(_node1)
-    const variableDeclarationName =
-      _node1.node?.declarations?.[0]?.id?.name || ''
+    const variableDeclarationName = isNodeType<VariableDeclaration>(
+      _node1.node,
+      'VariableDeclaration'
+    )
+      ? _node1.node.declarations[0]?.id?.name || ''
+      : ''
 
     const sg = kclManager.programMemory.get(
       variableDeclarationName
@@ -728,15 +748,14 @@ export class SceneEntities {
   ) => {
     let _ast = structuredClone(kclManager.ast)
 
-    const _node1 = getNodeFromPath<VariableDeclaration>(
+    const varDec = expectNodeOnPath<VariableDeclaration>(
       _ast,
       sketchPathToNode || [],
       'VariableDeclaration'
     )
-    if (trap(_node1)) return Promise.reject(_node1)
-    const variableDeclarationName =
-      _node1.node?.declarations?.[0]?.id?.name || ''
-    const startSketchOn = _node1.node?.declarations
+    if (trap(varDec)) return Promise.reject(varDec)
+    const variableDeclarationName = varDec.declarations?.[0]?.id?.name || ''
+    const startSketchOn = varDec.declarations
     const startSketchOnInit = startSketchOn?.[0]?.init
 
     const tags: [string, string, string] = [
@@ -775,12 +794,17 @@ export class SceneEntities {
           'VariableDeclaration'
         )
         if (trap(_node)) return Promise.reject(_node)
-        const sketchInit = _node.node?.declarations?.[0]?.init
+        const sketchInit = isNodeType<VariableDeclaration>(
+          _node.node,
+          'VariableDeclaration'
+        )
+          ? _node.node.declarations[0]?.init
+          : null
 
         const x = (args.intersectionPoint.twoD.x || 0) - rectangleOrigin[0]
         const y = (args.intersectionPoint.twoD.y || 0) - rectangleOrigin[1]
 
-        if (sketchInit.type === 'PipeExpression') {
+        if (sketchInit?.type === 'PipeExpression') {
           updateRectangleSketch(sketchInit, x, y, tags[0])
         }
 
@@ -823,9 +847,14 @@ export class SceneEntities {
           'VariableDeclaration'
         )
         if (trap(_node)) return Promise.reject(_node)
-        const sketchInit = _node.node?.declarations?.[0]?.init
+        const sketchInit = isNodeType<VariableDeclaration>(
+          _node.node,
+          'VariableDeclaration'
+        )
+          ? _node.node.declarations[0]?.init
+          : null
 
-        if (sketchInit.type === 'PipeExpression') {
+        if (sketchInit?.type === 'PipeExpression') {
           updateRectangleSketch(sketchInit, x, y, tags[0])
 
           let _recastAst = parse(recast(_ast))
@@ -1061,7 +1090,7 @@ export class SceneEntities {
     if (trap(_node)) return
     const node = _node.node
 
-    if (node.type !== 'CallExpression') return
+    if (isArray(node) || node.type !== 'CallExpression') return
 
     let modded:
       | {
@@ -1666,7 +1695,9 @@ export class SceneEntities {
           )
           if (trap(_node, { suppress: true })) return
           const node = _node.node
-          editorManager.setHighlightRange([node.start, node.end])
+          editorManager.setHighlightRange(
+            !isArray(node) ? [node.start, node.end] : [0, 0]
+          )
           const yellow = 0xffff00
           colorSegment(selected, yellow)
           const extraSegmentGroup = parent.getObjectByName(EXTRA_SEGMENT_HANDLE)
@@ -1796,7 +1827,14 @@ function prepareTruncatedMemoryAndAst(
     'VariableDeclaration'
   )
   if (err(_node)) return _node
-  const variableDeclarationName = _node.node?.declarations?.[0]?.id?.name || ''
+  if (isArray(_node.node))
+    return new Error('Expected node to be an object, but found Array')
+  const variableDeclarationName = isNodeType<VariableDeclaration>(
+    _node.node,
+    'VariableDeclaration'
+  )
+    ? _node.node.declarations[0]?.id?.name || ''
+    : ''
   const lastSeg = (
     programMemory.get(variableDeclarationName) as SketchGroup
   ).value.slice(-1)[0]
@@ -1919,7 +1957,12 @@ export function sketchGroupFromPathToNode({
   )
   if (err(_varDec)) return _varDec
   const varDec = _varDec.node
-  const result = programMemory.get(varDec?.id?.name || '')
+  if (isArray(varDec))
+    return new Error('Expected node to be an object, but found Array')
+  const varName = isNodeType<VariableDeclarator>(varDec, 'VariableDeclarator')
+    ? varDec.id.name
+    : ''
+  const result = programMemory.get(varName)
   if (result?.type === 'ExtrudeGroup') {
     return result.sketchGroup
   }

src/components/Toolbar/EqualAngle.tsx

@@ -1,9 +1,12 @@
 import { toolTips } from 'lang/langHelpers'
 import { Selections } from 'lib/selections'
-import { Program, Value, VariableDeclarator } from '../../lang/wasm'
+import { CallExpression, Program, VariableDeclarator } from '../../lang/wasm'
 import {
   getNodePathFromSourceRange,
-  getNodeFromPath,
+  getLastNodeFromPath,
+  DynamicNode,
+  isNodeType,
+  expectNodeOnPath,
 } from '../../lang/queryAst'
 import { isSketchVariablesLinked } from '../../lang/std/sketchConstraints'
 import {
@@ -14,6 +17,7 @@ import {
 } from '../../lang/std/sketchcombos'
 import { kclManager } from 'lib/singletons'
 import { err } from 'lib/trap'
+import { isArray } from 'lib/utils'
 
 export function equalAngleInfo({
   selectionRanges,
@@ -29,26 +33,33 @@ export function equalAngleInfo({
     getNodePathFromSourceRange(kclManager.ast, range)
   )
   const _nodes = paths.map((pathToNode) => {
-    const tmp = getNodeFromPath<Value>(kclManager.ast, pathToNode)
+    const tmp = getLastNodeFromPath(kclManager.ast, pathToNode)
     if (err(tmp)) return tmp
+    if (isArray(tmp.node)) {
+      return new Error('Expected value node, but found array')
+    }
     return tmp.node
   })
-  const _err1 = _nodes.find(err)
-  if (err(_err1)) return _err1
-  const nodes = _nodes as Value[]
+  const nodes: DynamicNode[] = []
+  for (const node of _nodes) {
+    if (err(node)) return node
+    nodes.push(node)
+  }
 
   const _varDecs = paths.map((pathToNode) => {
-    const tmp = getNodeFromPath<VariableDeclarator>(
+    const tmp = expectNodeOnPath<VariableDeclarator>(
       kclManager.ast,
       pathToNode,
       'VariableDeclarator'
     )
     if (err(tmp)) return tmp
-    return tmp.node
+    return tmp
   })
-  const _err2 = _varDecs.find(err)
-  if (err(_err2)) return _err2
-  const varDecs = _varDecs as VariableDeclarator[]
+  const varDecs: VariableDeclarator[] = []
+  for (const varDec of _varDecs) {
+    if (err(varDec)) return varDec
+    varDecs.push(varDec)
+  }
 
   const primaryLine = varDecs[0]
   const secondaryVarDecs = varDecs.slice(1)
@@ -57,7 +68,7 @@ export function equalAngleInfo({
   )
   const isAllTooltips = nodes.every(
     (node) =>
-      node?.type === 'CallExpression' &&
+      isNodeType<CallExpression>(node, 'CallExpression') &&
       toolTips.includes(node.callee.name as any)
   )
 

src/components/Toolbar/EqualLength.tsx

@@ -1,9 +1,12 @@
 import { toolTips } from 'lang/langHelpers'
 import { Selections } from 'lib/selections'
-import { Program, Value, VariableDeclarator } from '../../lang/wasm'
+import { CallExpression, Program, VariableDeclarator } from '../../lang/wasm'
 import {
   getNodePathFromSourceRange,
-  getNodeFromPath,
+  getLastNodeFromPath,
+  DynamicNode,
+  isNodeType,
+  expectNodeOnPath,
 } from '../../lang/queryAst'
 import { isSketchVariablesLinked } from '../../lang/std/sketchConstraints'
 import {
@@ -14,6 +17,7 @@ import {
 } from '../../lang/std/sketchcombos'
 import { kclManager } from 'lib/singletons'
 import { err } from 'lib/trap'
+import { isArray } from 'lib/utils'
 
 export function setEqualLengthInfo({
   selectionRanges,
@@ -29,26 +33,33 @@ export function setEqualLengthInfo({
     getNodePathFromSourceRange(kclManager.ast, range)
   )
   const _nodes = paths.map((pathToNode) => {
-    const tmp = getNodeFromPath<Value>(kclManager.ast, pathToNode)
+    const tmp = getLastNodeFromPath(kclManager.ast, pathToNode)
     if (err(tmp)) return tmp
+    if (isArray(tmp.node)) {
+      return new Error('Expected value node, but found array')
+    }
     return tmp.node
   })
-  const _err1 = _nodes.find(err)
-  if (err(_err1)) return _err1
-  const nodes = _nodes as Value[]
+  const nodes: DynamicNode[] = []
+  for (const node of _nodes) {
+    if (err(node)) return node
+    nodes.push(node)
+  }
 
   const _varDecs = paths.map((pathToNode) => {
-    const tmp = getNodeFromPath<VariableDeclarator>(
+    const varDec = expectNodeOnPath<VariableDeclarator>(
       kclManager.ast,
       pathToNode,
       'VariableDeclarator'
     )
-    if (err(tmp)) return tmp
-    return tmp.node
+    if (err(varDec)) return varDec
+    return varDec
   })
-  const _err2 = _varDecs.find(err)
-  if (err(_err2)) return _err2
-  const varDecs = _varDecs as VariableDeclarator[]
+  const varDecs: VariableDeclarator[] = []
+  for (const varDec of _varDecs) {
+    if (err(varDec)) return varDec
+    varDecs.push(varDec)
+  }
 
   const primaryLine = varDecs[0]
   const secondaryVarDecs = varDecs.slice(1)
@@ -57,7 +68,7 @@ export function setEqualLengthInfo({
   )
   const isAllTooltips = nodes.every(
     (node) =>
-      node?.type === 'CallExpression' &&
+      isNodeType<CallExpression>(node, 'CallExpression') &&
       toolTips.includes(node.callee.name as any)
   )
 

src/components/Toolbar/HorzVert.tsx

@@ -1,9 +1,11 @@
 import { toolTips } from 'lang/langHelpers'
 import { Selections } from 'lib/selections'
-import { Program, ProgramMemory, Value } from '../../lang/wasm'
+import { CallExpression, Program, ProgramMemory } from '../../lang/wasm'
 import {
   getNodePathFromSourceRange,
-  getNodeFromPath,
+  getLastNodeFromPath,
+  DynamicNode,
+  isNodeType,
 } from '../../lang/queryAst'
 import {
   PathToNodeMap,
@@ -13,6 +15,7 @@ import {
 } from '../../lang/std/sketchcombos'
 import { kclManager } from 'lib/singletons'
 import { err } from 'lib/trap'
+import { isArray } from 'lib/utils'
 
 export function horzVertInfo(
   selectionRanges: Selections,
@@ -27,17 +30,22 @@ export function horzVertInfo(
     getNodePathFromSourceRange(kclManager.ast, range)
   )
   const _nodes = paths.map((pathToNode) => {
-    const tmp = getNodeFromPath<Value>(kclManager.ast, pathToNode)
+    const tmp = getLastNodeFromPath(kclManager.ast, pathToNode)
     if (err(tmp)) return tmp
+    if (isArray(tmp.node)) {
+      return new Error('Expected value node, but found array')
+    }
     return tmp.node
   })
-  const _err1 = _nodes.find(err)
-  if (err(_err1)) return _err1
-  const nodes = _nodes as Value[]
+  const nodes: DynamicNode[] = []
+  for (const node of _nodes) {
+    if (err(node)) return node
+    nodes.push(node)
+  }
 
   const isAllTooltips = nodes.every(
     (node) =>
-      node?.type === 'CallExpression' &&
+      isNodeType<CallExpression>(node, 'CallExpression') &&
       toolTips.includes(node.callee.name as any)
   )
 

src/components/Toolbar/Intersect.tsx

@@ -1,10 +1,18 @@
 import { toolTips } from 'lang/langHelpers'
 import { Selections } from 'lib/selections'
-import { BinaryPart, Program, Value, VariableDeclarator } from '../../lang/wasm'
+import {
+  BinaryPart,
+  CallExpression,
+  Program,
+  VariableDeclarator,
+} from '../../lang/wasm'
 import {
   getNodePathFromSourceRange,
-  getNodeFromPath,
   isLinesParallelAndConstrained,
+  getLastNodeFromPath,
+  expectNodeOnPath,
+  DynamicNode,
+  isNodeType,
 } from '../../lang/queryAst'
 import { isSketchVariablesLinked } from '../../lang/std/sketchConstraints'
 import {
@@ -18,6 +26,7 @@ import { createVariableDeclaration } from '../../lang/modifyAst'
 import { removeDoubleNegatives } from '../AvailableVarsHelpers'
 import { kclManager } from 'lib/singletons'
 import { err } from 'lib/trap'
+import { isArray } from 'lib/utils'
 
 const getModalInfo = createInfoModal(GetInfoModal)
 
@@ -72,26 +81,33 @@ export function intersectInfo({
     getNodePathFromSourceRange(kclManager.ast, range)
   )
   const _nodes = paths.map((pathToNode) => {
-    const tmp = getNodeFromPath<Value>(kclManager.ast, pathToNode)
+    const tmp = getLastNodeFromPath(kclManager.ast, pathToNode)
     if (err(tmp)) return tmp
+    if (isArray(tmp.node)) {
+      return new Error('Expected value node, but found array')
+    }
     return tmp.node
   })
-  const _err1 = _nodes.find(err)
-  if (err(_err1)) return _err1
-  const nodes = _nodes as Value[]
+  const nodes: DynamicNode[] = []
+  for (const node of _nodes) {
+    if (err(node)) return node
+    nodes.push(node)
+  }
 
   const _varDecs = paths.map((pathToNode) => {
-    const tmp = getNodeFromPath<VariableDeclarator>(
+    const varDec = expectNodeOnPath<VariableDeclarator>(
       kclManager.ast,
       pathToNode,
       'VariableDeclarator'
     )
-    if (err(tmp)) return tmp
-    return tmp.node
+    if (err(varDec)) return varDec
+    return varDec
   })
-  const _err2 = _varDecs.find(err)
-  if (err(_err2)) return _err2
-  const varDecs = _varDecs as VariableDeclarator[]
+  const varDecs: VariableDeclarator[] = []
+  for (const varDec of _varDecs) {
+    if (err(varDec)) return varDec
+    varDecs.push(varDec)
+  }
 
   const primaryLine = varDecs[0]
   const secondaryVarDecs = varDecs.slice(1)
@@ -100,7 +116,7 @@ export function intersectInfo({
   )
   const isAllTooltips = nodes.every(
     (node) =>
-      node?.type === 'CallExpression' &&
+      isNodeType<CallExpression>(node, 'CallExpression') &&
       [
         ...toolTips,
         'startSketchAt', // TODO probably a better place for this to live

src/components/Toolbar/RemoveConstrainingValues.tsx

@@ -1,9 +1,11 @@
 import { toolTips } from 'lang/langHelpers'
 import { Selection, Selections } from 'lib/selections'
-import { PathToNode, Program, Value } from '../../lang/wasm'
+import { CallExpression, PathToNode, Program } from '../../lang/wasm'
 import {
   getNodePathFromSourceRange,
-  getNodeFromPath,
+  getLastNodeFromPath,
+  DynamicNode,
+  isNodeType,
 } from '../../lang/queryAst'
 import {
   PathToNodeMap,
@@ -13,6 +15,7 @@ import {
 } from '../../lang/std/sketchcombos'
 import { kclManager } from 'lib/singletons'
 import { err } from 'lib/trap'
+import { isArray } from 'lib/utils'
 
 export function removeConstrainingValuesInfo({
   selectionRanges,
@@ -33,13 +36,18 @@ export function removeConstrainingValuesInfo({
       getNodePathFromSourceRange(kclManager.ast, range)
     )
   const _nodes = paths.map((pathToNode) => {
-    const tmp = getNodeFromPath<Value>(kclManager.ast, pathToNode)
+    const tmp = getLastNodeFromPath(kclManager.ast, pathToNode)
     if (err(tmp)) return tmp
+    if (isArray(tmp.node)) {
+      return new Error('Expected value node, but found array')
+    }
     return tmp.node
   })
-  const _err1 = _nodes.find(err)
-  if (err(_err1)) return _err1
-  const nodes = _nodes as Value[]
+  const nodes: DynamicNode[] = []
+  for (const node of _nodes) {
+    if (err(node)) return node
+    nodes.push(node)
+  }
 
   const updatedSelectionRanges = pathToNodes
     ? {
@@ -54,7 +62,7 @@ export function removeConstrainingValuesInfo({
     : selectionRanges
   const isAllTooltips = nodes.every(
     (node) =>
-      node?.type === 'CallExpression' &&
+      isNodeType<CallExpression>(node, 'CallExpression') &&
       toolTips.includes(node.callee.name as any)
   )
 

src/components/Toolbar/SetAbsDistance.tsx

@@ -1,6 +1,6 @@
 import { toolTips } from 'lang/langHelpers'
 import { Selections } from 'lib/selections'
-import { BinaryPart, Program, Value } from '../../lang/wasm'
+import { BinaryPart, CallExpression, Program, Value } from '../../lang/wasm'
 import {
   getNodePathFromSourceRange,
   getNodeFromPath,
@@ -49,22 +49,22 @@ export function absDistanceInfo({
     getNodePathFromSourceRange(kclManager.ast, range)
   )
   const _nodes = paths.map((pathToNode) => {
-    const tmp = getNodeFromPath<Value>(
+    const tmp = getNodeFromPath<CallExpression>(
       kclManager.ast,
       pathToNode,
       'CallExpression'
     )
     if (err(tmp)) return tmp
-    return tmp.node
+    return tmp.stopAtNode
   })
-  const _err1 = _nodes.find(err)
-  if (err(_err1)) return _err1
-  const nodes = _nodes as Value[]
+  const nodes: (CallExpression | null)[] = []
+  for (const node of _nodes) {
+    if (err(node)) return node
+    nodes.push(node)
+  }
 
   const isAllTooltips = nodes.every(
-    (node) =>
-      node?.type === 'CallExpression' &&
-      toolTips.includes(node.callee.name as any)
+    (node) => node && toolTips.includes(node.callee.name as any)
   )
 
   const transforms = getTransformInfos(selectionRanges, kclManager.ast, disType)

src/components/Toolbar/SetAngleBetween.tsx

@@ -1,9 +1,17 @@
 import { toolTips } from 'lang/langHelpers'
 import { Selections } from 'lib/selections'
-import { BinaryPart, Program, Value, VariableDeclarator } from '../../lang/wasm'
+import {
+  BinaryPart,
+  CallExpression,
+  Program,
+  VariableDeclarator,
+} from '../../lang/wasm'
 import {
   getNodePathFromSourceRange,
-  getNodeFromPath,
+  getLastNodeFromPath,
+  DynamicNode,
+  expectNodeOnPath,
+  isNodeType,
 } from '../../lang/queryAst'
 import { isSketchVariablesLinked } from '../../lang/std/sketchConstraints'
 import {
@@ -17,6 +25,7 @@ import { createVariableDeclaration } from '../../lang/modifyAst'
 import { removeDoubleNegatives } from '../AvailableVarsHelpers'
 import { kclManager } from 'lib/singletons'
 import { err } from 'lib/trap'
+import { isArray } from 'lib/utils'
 
 const getModalInfo = createInfoModal(GetInfoModal)
 
@@ -35,26 +44,33 @@ export function angleBetweenInfo({
   )
 
   const _nodes = paths.map((pathToNode) => {
-    const tmp = getNodeFromPath<Value>(kclManager.ast, pathToNode)
+    const tmp = getLastNodeFromPath(kclManager.ast, pathToNode)
     if (err(tmp)) return tmp
+    if (isArray(tmp.node)) {
+      return new Error('Expected value node, but found array')
+    }
     return tmp.node
   })
-  const _err1 = _nodes.find(err)
-  if (err(_err1)) return _err1
-  const nodes = _nodes as Value[]
+  const nodes: DynamicNode[] = []
+  for (const node of _nodes) {
+    if (err(node)) return node
+    nodes.push(node)
+  }
 
   const _varDecs = paths.map((pathToNode) => {
-    const tmp = getNodeFromPath<VariableDeclarator>(
+    const varDec = expectNodeOnPath<VariableDeclarator>(
       kclManager.ast,
       pathToNode,
       'VariableDeclarator'
     )
-    if (err(tmp)) return tmp
-    return tmp.node
+    if (err(varDec)) return varDec
+    return varDec
   })
-  const _err2 = _varDecs.find(err)
-  if (err(_err2)) return _err2
-  const varDecs = _varDecs as VariableDeclarator[]
+  const varDecs: VariableDeclarator[] = []
+  for (const varDec of _varDecs) {
+    if (err(varDec)) return varDec
+    varDecs.push(varDec)
+  }
 
   const primaryLine = varDecs[0]
   const secondaryVarDecs = varDecs.slice(1)
@@ -63,7 +79,7 @@ export function angleBetweenInfo({
   )
   const isAllTooltips = nodes.every(
     (node) =>
-      node?.type === 'CallExpression' &&
+      isNodeType<CallExpression>(node, 'CallExpression') &&
       toolTips.includes(node.callee.name as any)
   )
 

src/components/Toolbar/SetHorzVertDistance.tsx

@@ -1,8 +1,15 @@
 import { toolTips } from 'lang/langHelpers'
-import { BinaryPart, Program, Value, VariableDeclarator } from '../../lang/wasm'
+import {
+  BinaryPart,
+  CallExpression,
+  Program,
+  VariableDeclarator,
+} from '../../lang/wasm'
 import {
   getNodePathFromSourceRange,
-  getNodeFromPath,
+  getLastNodeFromPath,
+  expectNodeOnPath,
+  isNodeType,
 } from '../../lang/queryAst'
 import { isSketchVariablesLinked } from '../../lang/std/sketchConstraints'
 import {
@@ -17,6 +24,7 @@ import { removeDoubleNegatives } from '../AvailableVarsHelpers'
 import { kclManager } from 'lib/singletons'
 import { Selections } from 'lib/selections'
 import { cleanErrs, err } from 'lib/trap'
+import { isArray } from 'lib/utils'
 
 const getModalInfo = createInfoModal(GetInfoModal)
 
@@ -36,27 +44,31 @@ export function horzVertDistanceInfo({
     getNodePathFromSourceRange(kclManager.ast, range)
   )
   const _nodes = paths.map((pathToNode) => {
-    const tmp = getNodeFromPath<Value>(kclManager.ast, pathToNode)
+    const tmp = getLastNodeFromPath(kclManager.ast, pathToNode)
     if (err(tmp)) return tmp
+    if (isArray(tmp.node)) {
+      return new Error('Expected value node, but found array')
+    }
     return tmp.node
   })
-  const [hasErr, , nodesWErrs] = cleanErrs(_nodes)
+  const [hasErr, nodes, nodesWErrs] = cleanErrs(_nodes)
 
   if (hasErr) return nodesWErrs[0]
-  const nodes = _nodes as Value[]
 
   const _varDecs = paths.map((pathToNode) => {
-    const tmp = getNodeFromPath<VariableDeclarator>(
+    const varDec = expectNodeOnPath<VariableDeclarator>(
       kclManager.ast,
       pathToNode,
       'VariableDeclarator'
     )
-    if (err(tmp)) return tmp
-    return tmp.node
+    if (err(varDec)) return varDec
+    return varDec
   })
-  const _err2 = _varDecs.find(err)
-  if (err(_err2)) return _err2
-  const varDecs = _varDecs as VariableDeclarator[]
+  const varDecs: VariableDeclarator[] = []
+  for (const varDec of _varDecs) {
+    if (err(varDec)) return varDec
+    varDecs.push(varDec)
+  }
 
   const primaryLine = varDecs[0]
   const secondaryVarDecs = varDecs.slice(1)
@@ -65,7 +77,7 @@ export function horzVertDistanceInfo({
   )
   const isAllTooltips = nodes.every(
     (node) =>
-      node?.type === 'CallExpression' &&
+      isNodeType<CallExpression>(node, 'CallExpression') &&
       [
         ...toolTips,
         'startSketchAt', // TODO probably a better place for this to live

src/components/Toolbar/setAngleLength.tsx

@@ -1,6 +1,6 @@
 import { toolTips } from 'lang/langHelpers'
 import { Selections } from 'lib/selections'
-import { BinaryPart, Program, Value } from '../../lang/wasm'
+import { BinaryPart, CallExpression, Program } from '../../lang/wasm'
 import {
   getNodePathFromSourceRange,
   getNodeFromPath,
@@ -43,18 +43,24 @@ export function angleLengthInfo({
     getNodePathFromSourceRange(kclManager.ast, range)
   )
 
-  const nodes = paths.map((pathToNode) =>
-    getNodeFromPath<Value>(kclManager.ast, pathToNode, 'CallExpression')
-  )
-  const _err1 = nodes.find(err)
-  if (err(_err1)) return _err1
-
-  const isAllTooltips = nodes.every((meta) => {
-    if (err(meta)) return false
-    return (
-      meta.node?.type === 'CallExpression' &&
-      toolTips.includes(meta.node.callee.name as any)
+  const _nodes = paths.map((pathToNode) => {
+    const tmp = getNodeFromPath<CallExpression>(
+      kclManager.ast,
+      pathToNode,
+      'CallExpression'
     )
+    if (err(tmp)) return tmp
+    return tmp.stopAtNode
+  })
+  const nodes: (CallExpression | null)[] = []
+  for (const node of _nodes) {
+    if (err(node)) return node
+    nodes.push(node)
+  }
+
+  const isAllTooltips = nodes.every((node) => {
+    if (err(node)) return false
+    return node && toolTips.includes(node.callee.name as any)
   })
 
   const transforms = getTransformInfos(

src/lang/KclSingleton.ts

@@ -1,7 +1,7 @@
 import { executeAst, lintAst } from 'lang/langHelpers'
 import { Selections } from 'lib/selections'
 import { KCLError, kclErrorsToDiagnostics } from './errors'
-import { uuidv4 } from 'lib/utils'
+import { isArray, uuidv4 } from 'lib/utils'
 import { EngineCommandManager } from './std/engineConnection'
 import { err } from 'lib/trap'
 
@@ -15,12 +15,17 @@ import {
   recast,
   SourceRange,
 } from 'lang/wasm'
-import { getNodeFromPath } from './queryAst'
+import {
+  expectNodeOnPath,
+  getLastNodeFromPath,
+  getNodeFromPath,
+} from './queryAst'
 import { codeManager, editorManager, sceneInfra } from 'lib/singletons'
 import { Diagnostic } from '@codemirror/lint'
 
 export class KclManager {
   private _ast: Program = {
+    type: 'Program',
     body: [],
     start: 0,
     end: 0,
@@ -156,6 +161,7 @@ export class KclManager {
 
   clearAst() {
     this._ast = {
+      type: 'Program',
       body: [],
       start: 0,
       end: 0,
@@ -313,14 +319,14 @@ export class KclManager {
     Object.entries(this.engineCommandManager.artifactMap).forEach(
       ([commandId, artifact]) => {
         if (!artifact.pathToNode) return
-        const _node1 = getNodeFromPath<CallExpression>(
+        const _node = getNodeFromPath<CallExpression>(
           this.ast,
           artifact.pathToNode,
           'CallExpression'
         )
-        if (err(_node1)) return
-        const { node } = _node1
-        if (node.type !== 'CallExpression') return
+        if (err(_node)) return
+        const { node } = _node
+        if (isArray(node) || node.type !== 'CallExpression') return
         const [oldStart, oldEnd] = artifact.range
         if (oldStart === 0 && oldEnd === 0) return
         if (oldStart === node.start && oldEnd === node.end) return
@@ -392,12 +398,15 @@ export class KclManager {
     let returnVal: Selections | undefined = undefined
 
     if (optionalParams?.focusPath) {
-      const _node1 = getNodeFromPath<any>(
+      const _node1 = getLastNodeFromPath(
         astWithUpdatedSource,
         optionalParams?.focusPath
       )
       if (err(_node1)) return Promise.reject(_node1)
       const { node } = _node1
+      if (isArray(node)) {
+        return Promise.reject(new Error('Expected node to not be an array'))
+      }
 
       const { start, end } = node
       if (!start || !end)

src/lang/getNodePathFromSourceRange.test.ts

@@ -1,4 +1,5 @@
-import { getNodePathFromSourceRange, getNodeFromPath } from './queryAst'
+import { isArray } from 'lib/utils'
+import { getNodePathFromSourceRange, getLastNodeFromPath } from './queryAst'
 import { Identifier, parse, initPromise, Parameter } from './wasm'
 import { err } from 'lib/trap'
 
@@ -25,10 +26,13 @@ const sk3 = startSketchAt([0, 0])
     const ast = parse(code)
     if (err(ast)) throw ast
     const nodePath = getNodePathFromSourceRange(ast, sourceRange)
-    const _node = getNodeFromPath<any>(ast, nodePath)
+    const _node = getLastNodeFromPath(ast, nodePath)
     if (err(_node)) throw _node
     const { node } = _node
 
+    if (isArray(node)) {
+      throw new Error('Expected call expression node, but found array')
+    }
     expect([node.start, node.end]).toEqual(sourceRange)
     expect(node.type).toBe('CallExpression')
   })
@@ -53,7 +57,7 @@ const b1 = cube([0,0], 10)`
     const ast = parse(code)
     if (err(ast)) throw ast
     const nodePath = getNodePathFromSourceRange(ast, sourceRange)
-    const _node = getNodeFromPath<Parameter>(ast, nodePath)
+    const _node = getLastNodeFromPath(ast, nodePath)
     if (err(_node)) throw _node
     const node = _node.node
 
@@ -66,8 +70,12 @@ const b1 = cube([0,0], 10)`
       ['params', 'FunctionExpression'],
       [0, 'index'],
     ])
+    if (isArray(node)) {
+      throw new Error('Expected parameter node, but found array')
+    }
     expect(node.type).toBe('Parameter')
-    expect(node.identifier.name).toBe('pos')
+    const param = node as any as Parameter
+    expect(param.identifier.name).toBe('pos')
   })
   it('gets path right for deep within function definition body', () => {
     const code = `fn cube = (pos, scale) => {
@@ -90,7 +98,7 @@ const b1 = cube([0,0], 10)`
     const ast = parse(code)
     if (err(ast)) throw ast
     const nodePath = getNodePathFromSourceRange(ast, sourceRange)
-    const _node = getNodeFromPath<Identifier>(ast, nodePath)
+    const _node = getLastNodeFromPath(ast, nodePath)
     if (err(_node)) throw _node
     const node = _node.node
     expect(nodePath).toEqual([
@@ -112,7 +120,11 @@ const b1 = cube([0,0], 10)`
       ['elements', 'ArrayExpression'],
       [0, 'index'],
     ])
+    if (isArray(node)) {
+      throw new Error('Expected identifier node, but found array')
+    }
     expect(node.type).toBe('Identifier')
-    expect(node.name).toBe('scale')
+    const ident = node as any as Identifier
+    expect(ident.name).toBe('scale')
   })
 })

src/lang/modifyAst.test.ts

@@ -119,6 +119,7 @@ describe('Testing addSketchTo', () => {
   it('should add a sketch to a program', () => {
     const result = addSketchTo(
       {
+        type: 'Program',
         body: [],
         start: 0,
         end: 0,

src/lang/modifyAst.ts

@@ -27,6 +27,8 @@ import {
   getNodePathFromSourceRange,
   isNodeSafeToReplace,
   traverse,
+  getLastNodeFromPath,
+  expectNodeOnPath,
 } from './queryAst'
 import { addTagForSketchOnFace, getConstraintInfo } from './std/sketch'
 import {
@@ -36,7 +38,7 @@ import {
   transformAstSketchLines,
 } from './std/sketchcombos'
 import { DefaultPlaneStr } from 'clientSideScene/sceneEntities'
-import { isOverlap, roundOff } from 'lib/utils'
+import { isArray, isOverlap, roundOff } from 'lib/utils'
 import { KCL_DEFAULT_CONSTANT_PREFIXES } from 'lib/constants'
 import { ConstrainInfo } from './std/stdTypes'
 import { TagDeclarator } from 'wasm-lib/kcl/bindings/TagDeclarator'
@@ -79,16 +81,12 @@ export function addStartProfileAt(
   pathToNode: PathToNode,
   at: [number, number]
 ): { modifiedAst: Program; pathToNode: PathToNode } | Error {
-  const _node1 = getNodeFromPath<VariableDeclaration>(
+  const variableDeclaration = expectNodeOnPath<VariableDeclaration>(
     node,
     pathToNode,
     'VariableDeclaration'
   )
-  if (err(_node1)) return _node1
-  const variableDeclaration = _node1.node
-  if (variableDeclaration.type !== 'VariableDeclaration') {
-    return new Error('variableDeclaration.init.type !== PipeExpression')
-  }
+  if (err(variableDeclaration)) return variableDeclaration
   const _node = { ...node }
   const init = variableDeclaration.declarations[0].init
   const startProfileAt = createCallExpressionStdLib('startProfileAt', [
@@ -263,7 +261,7 @@ export function extrudeSketch(
     }
   | Error {
   const _node = { ...node }
-  const _node1 = getNodeFromPath(_node, pathToNode)
+  const _node1 = getLastNodeFromPath(_node, pathToNode)
   if (err(_node1)) return _node1
   const { node: sketchExpression } = _node1
 
@@ -274,9 +272,9 @@ export function extrudeSketch(
     'PipeExpression'
   )
   if (err(_node2)) return _node2
-  const { node: pipeExpression } = _node2
+  const { stopAtNode: pipeExpression } = _node2
 
-  const isInPipeExpression = pipeExpression.type === 'PipeExpression'
+  const isInPipeExpression = !!pipeExpression
 
   const _node3 = getNodeFromPath<VariableDeclarator>(
     _node,
@@ -284,7 +282,11 @@ export function extrudeSketch(
     'VariableDeclarator'
   )
   if (err(_node3)) return _node3
-  const { node: variableDeclarator, shallowPath: pathToDecleration } = _node3
+  const { stopAtNode: variableDeclarator, shallowPath: pathToDecleration } =
+    _node3
+  if (!variableDeclarator) {
+    return new Error('VariableDeclarator not found')
+  }
 
   const extrudeCall = createCallExpressionStdLib('extrude', [
     distance,
@@ -356,34 +358,34 @@ export function sketchOnExtrudedFace(
     node,
     KCL_DEFAULT_CONSTANT_PREFIXES.SKETCH
   )
-  const _node1 = getNodeFromPath<VariableDeclarator>(
+  const oldSketchNode = expectNodeOnPath<VariableDeclarator>(
     _node,
     sketchPathToNode,
     'VariableDeclarator',
-    true
+    {
+      firstFound: true,
+      message: 'Old sketch node not found',
+    }
   )
-  if (err(_node1)) return _node1
-  const { node: oldSketchNode } = _node1
+  if (err(oldSketchNode)) return oldSketchNode
 
   const oldSketchName = oldSketchNode.id.name
-  const _node2 = getNodeFromPath<CallExpression>(
+  const expression = expectNodeOnPath<CallExpression>(
     _node,
     sketchPathToNode,
     'CallExpression'
   )
-  if (err(_node2)) return _node2
-  const { node: expression } = _node2
+  if (err(expression)) return expression
 
-  const _node3 = getNodeFromPath<VariableDeclarator>(
+  const extrudeVarDec = expectNodeOnPath<VariableDeclarator>(
     _node,
     extrudePathToNode,
     'VariableDeclarator'
   )
-  if (err(_node3)) return _node3
-  const { node: extrudeVarDec } = _node3
-  const extrudeName = extrudeVarDec.id?.name
+  if (err(extrudeVarDec)) return extrudeVarDec
+  const extrudeName = extrudeVarDec.id.name
 
-  let _tag = null
+  let _tag: Identifier | Literal | null = null
   if (cap === 'none') {
     const __tag = addTagForSketchOnFace(
       {
@@ -678,9 +680,12 @@ export function giveSketchFnCallTag(
     }
   | Error {
   const path = getNodePathFromSourceRange(ast, range)
-  const _node1 = getNodeFromPath<CallExpression>(ast, path, 'CallExpression')
-  if (err(_node1)) return _node1
-  const { node: primaryCallExp } = _node1
+  const primaryCallExp = expectNodeOnPath<CallExpression>(
+    ast,
+    path,
+    'CallExpression'
+  )
+  if (err(primaryCallExp)) return primaryCallExp
 
   // Tag is always 3rd expression now, using arg index feels brittle
   // but we can come up with a better way to identify tag later.
@@ -784,27 +789,35 @@ export function deleteSegmentFromPipeExpression(
 ): Program | Error {
   let _modifiedAst = structuredClone(modifiedAst)
 
-  dependentRanges.forEach((range) => {
+  for (const range of dependentRanges) {
     const path = getNodePathFromSourceRange(_modifiedAst, range)
 
-    const callExp = getNodeFromPath<CallExpression>(
+    const _callExp = getNodeFromPath<CallExpression>(
       _modifiedAst,
       path,
       'CallExpression',
       true
     )
-    if (err(callExp)) return callExp
+    if (err(_callExp)) return _callExp
+    const callExp = _callExp.stopAtNode
+    if (!callExp) {
+      return new Error('Call Expression not found')
+    }
 
-    const constraintInfo = getConstraintInfo(callExp.node, code, path).find(
+    const constraintInfo = getConstraintInfo(callExp, code, path).find(
       ({ sourceRange }) => isOverlap(sourceRange, range)
     )
-    if (!constraintInfo) return
+    if (!constraintInfo) {
+      return new Error('Constraint Info not found')
+    }
 
     const input = makeRemoveSingleConstraintInput(
       constraintInfo.argPosition,
-      callExp.shallowPath
+      _callExp.shallowPath
     )
-    if (!input) return
+    if (!input) {
+      return new Error('Input not found')
+    }
     const transform = removeSingleConstraintInfo(
       {
         ...input,
@@ -812,11 +825,13 @@ export function deleteSegmentFromPipeExpression(
       _modifiedAst,
       programMemory
     )
-    if (!transform) return
+    if (!transform) {
+      return new Error('Transform not found')
+    }
     _modifiedAst = transform.modifiedAst
-  })
+  }
 
-  const pipeExpression = getNodeFromPath<PipeExpression>(
+  const pipeExpression = expectNodeOnPath<PipeExpression>(
     _modifiedAst,
     pathToNode,
     'PipeExpression'
@@ -827,7 +842,7 @@ export function deleteSegmentFromPipeExpression(
     ([_, desc]) => desc === 'PipeExpression'
   )
   const segmentIndexInPipe = pathToNode[pipeInPathIndex + 1]
-  pipeExpression.node.body.splice(segmentIndexInPipe[0] as number, 1)
+  pipeExpression.body.splice(segmentIndexInPipe[0] as number, 1)
 
   // Move up to the next segment.
   segmentIndexInPipe[0] = Math.max((segmentIndexInPipe[0] as number) - 1, 0)
@@ -902,19 +917,23 @@ export async function deleteFromSelection(
   const astClone = structuredClone(ast)
   const range = selection.range
   const path = getNodePathFromSourceRange(ast, range)
-  const varDec = getNodeFromPath<VariableDeclarator>(
+  const _varDec = getNodeFromPath<VariableDeclarator>(
     ast,
     path,
     'VariableDeclarator'
   )
-  if (err(varDec)) return varDec
+  if (err(_varDec)) return _varDec
+  const { stopAtNode: varDec } = _varDec
+  if (!varDec) {
+    return new Error('VariableDeclarator not found')
+  }
   if (
     (selection.type === 'extrude-wall' ||
       selection.type === 'end-cap' ||
       selection.type === 'start-cap') &&
-    varDec.node.init.type === 'PipeExpression'
+    varDec.init.type === 'PipeExpression'
   ) {
-    const varDecName = varDec.node.id.name
+    const varDecName = varDec.id.name
     let pathToNode: PathToNode | null = null
     let extrudeNameToDelete = ''
     traverse(astClone, {
@@ -976,13 +995,16 @@ export async function deleteFromSelection(
           lastKey: number
         }[] = []
         for (const { path, sketchName } of pathsDependingOnExtrude) {
-          const parent = getNodeFromPath<PipeExpression['body']>(
-            astClone,
-            path.slice(0, -1)
-          )
-          if (err(parent)) {
+          const _parent = getLastNodeFromPath(astClone, path.slice(0, -1))
+          if (err(_parent)) {
             return
           }
+          const { node: parent } = _parent
+          if (!isArray(parent)) {
+            console.error(`Parent is not an array: ${parent}`)
+            return
+          }
+          const pipeBodyItems = parent as PipeExpression['body']
           const sketchToPreserve = programMemory.get(sketchName) as SketchGroup
           console.log('sketchName', sketchName)
           // Can't kick off multiple requests at once as getFaceDetails
@@ -1000,7 +1022,7 @@ export async function deleteFromSelection(
           }
           const lastKey = Number(path.slice(-1)[0][0])
           modificationDetails.push({
-            parent: parent.node,
+            parent: pipeBodyItems,
             faceDetails,
             lastKey,
           })
@@ -1048,14 +1070,14 @@ export async function deleteFromSelection(
     }
     // await prom
     return astClone
-  } else if (varDec.node.init.type === 'PipeExpression') {
-    const pipeBody = varDec.node.init.body
+  } else if (varDec.init.type === 'PipeExpression') {
+    const pipeBody = varDec.init.body
     if (
       pipeBody[0].type === 'CallExpression' &&
       pipeBody[0].callee.name === 'startSketchOn'
     ) {
       // remove varDec
-      const varDecIndex = varDec.shallowPath[1][0] as number
+      const varDecIndex = _varDec.shallowPath[1][0] as number
       astClone.body.splice(varDecIndex, 1)
       return astClone
     }

src/lang/modifyAst/addFillet.test.ts

@@ -12,7 +12,7 @@ import {
   hasValidFilletSelection,
   isTagUsedInFillet,
 } from './addFillet'
-import { getNodeFromPath, getNodePathFromSourceRange } from '../queryAst'
+import { expectNodeOnPath, getNodePathFromSourceRange } from '../queryAst'
 import { createLiteral } from 'lang/modifyAst'
 import { err } from 'lib/trap'
 import { Selections } from 'lib/selections'
@@ -270,13 +270,13 @@ const extrude001 = extrude(-5, sketch001)
     ]
     const pathToNode = getNodePathFromSourceRange(ast, range)
     if (err(pathToNode)) return
-    const callExp = getNodeFromPath<CallExpression>(
+    const callExp = expectNodeOnPath<CallExpression>(
       ast,
       pathToNode,
       'CallExpression'
     )
     if (err(callExp)) return
-    const edges = isTagUsedInFillet({ ast, callExp: callExp.node })
+    const edges = isTagUsedInFillet({ ast, callExp })
     expect(edges).toEqual(['getOppositeEdge', 'baseEdge'])
   })
   it('should correctly identify getPreviousAdjacentEdge edges', () => {
@@ -289,13 +289,13 @@ const extrude001 = extrude(-5, sketch001)
     ]
     const pathToNode = getNodePathFromSourceRange(ast, range)
     if (err(pathToNode)) return
-    const callExp = getNodeFromPath<CallExpression>(
+    const callExp = expectNodeOnPath<CallExpression>(
       ast,
       pathToNode,
       'CallExpression'
     )
     if (err(callExp)) return
-    const edges = isTagUsedInFillet({ ast, callExp: callExp.node })
+    const edges = isTagUsedInFillet({ ast, callExp })
     expect(edges).toEqual(['getPreviousAdjacentEdge'])
   })
   it('should correctly identify no edges', () => {
@@ -308,13 +308,13 @@ const extrude001 = extrude(-5, sketch001)
     ]
     const pathToNode = getNodePathFromSourceRange(ast, range)
     if (err(pathToNode)) return
-    const callExp = getNodeFromPath<CallExpression>(
+    const callExp = expectNodeOnPath<CallExpression>(
       ast,
       pathToNode,
       'CallExpression'
     )
     if (err(callExp)) return
-    const edges = isTagUsedInFillet({ ast, callExp: callExp.node })
+    const edges = isTagUsedInFillet({ ast, callExp })
     expect(edges).toEqual([])
   })
 })

src/lang/modifyAst/addFillet.ts

@@ -18,6 +18,7 @@ import {
   createPipeExpression,
 } from '../modifyAst'
 import {
+  expectNodeOnPath,
   getNodeFromPath,
   getNodePathFromSourceRange,
   hasSketchPipeBeenExtruded,
@@ -46,15 +47,12 @@ export function addFillet(
    */
 
   // Find the specific sketch segment to tag with the new tag
-  const sketchSegmentChunk = getNodeFromPath(
+  const sketchSegmentNode = expectNodeOnPath<CallExpression>(
     _node,
     pathToSegmentNode,
     'CallExpression'
   )
-  if (err(sketchSegmentChunk)) return sketchSegmentChunk
-  const { node: sketchSegmentNode } = sketchSegmentChunk as {
-    node: CallExpression
-  }
+  if (err(sketchSegmentNode)) return sketchSegmentNode
 
   // Check whether selection is a valid segment from sketchLineHelpersMap
   if (!(sketchSegmentNode.callee.name in sketchLineHelperMap)) {
@@ -93,13 +91,12 @@ export function addFillet(
   ])
 
   // Locate the extrude call
-  const extrudeChunk = getNodeFromPath<VariableDeclaration>(
+  const extrudeVarDecl = expectNodeOnPath<VariableDeclaration>(
     _node,
     pathToExtrudeNode,
     'VariableDeclaration'
   )
-  if (err(extrudeChunk)) return extrudeChunk
-  const { node: extrudeVarDecl } = extrudeChunk
+  if (err(extrudeVarDecl)) return extrudeVarDecl
 
   const extrudeDeclarator = extrudeVarDecl.declarations[0]
   const extrudeInit = extrudeDeclarator.init
@@ -281,12 +278,12 @@ export const hasValidFilletSelection = ({
         'CallExpression'
       )
       if (err(segmentNode)) return false
-      if (segmentNode.node.type === 'CallExpression') {
-        const segmentName = segmentNode.node.callee.name
+      if (segmentNode.stopAtNode) {
+        const segmentName = segmentNode.stopAtNode.callee.name
         if (segmentName in sketchLineHelperMap) {
           const edges = isTagUsedInFillet({
             ast,
-            callExp: segmentNode.node,
+            callExp: segmentNode.stopAtNode,
           })
           // edge has already been filleted
           if (

src/lang/queryAst.ts

@@ -19,13 +19,47 @@ import {
 } from './wasm'
 import { createIdentifier, splitPathAtLastIndex } from './modifyAst'
 import { getSketchSegmentFromSourceRange } from './std/sketchConstraints'
-import { getAngle } from '../lib/utils'
+import { getAngle, isArray } from '../lib/utils'
 import { getFirstArg } from './std/sketch'
 import {
   getConstraintLevelFromSourceRange,
   getConstraintType,
 } from './std/sketchcombos'
 import { err } from 'lib/trap'
+import { BodyItem } from 'wasm-lib/kcl/bindings/BodyItem'
+
+export interface DynamicNode {
+  type: SyntaxType
+  // Source range of the node.
+  start: number
+  end: number
+  [index: string]: unknown
+}
+
+function isAstNode(
+  node: any
+): node is { type: SyntaxType; start: number; end: number } {
+  // TODO: Should we check for start and end also?
+  return node && typeof node === 'object' && 'type' in node
+}
+
+/**
+ * Given T and its corresponding SyntaxType, narrow the node to type T if
+ * node.type matches.
+ */
+export function isNodeType<T extends DynamicNode>(
+  node: unknown,
+  syntaxType: SyntaxType | SyntaxType[]
+): node is T {
+  return (
+    !!node &&
+    typeof node === 'object' &&
+    'type' in node &&
+    (isArray(syntaxType)
+      ? syntaxType.includes(node.type as SyntaxType)
+      : node.type === syntaxType)
+  )
+}
 
 /**
  * Retrieves a node from a given path within a Program node structure, optionally stopping at a specified node type.
@@ -33,51 +67,64 @@ import { err } from 'lib/trap'
  * and return the node at the end of this path.
  * By default it will return the node of the deepest "stopAt" type encountered, or the node at the end of the path if no "stopAt" type is provided.
  * If the "returnEarly" flag is set to true, the function will return as soon as a node of the specified type is found.
+ *
+ * If stopAt is provided, it must match T's type property.
  */
-export function getNodeFromPath<T>(
+export function getNodeFromPath<T extends DynamicNode>(
   node: Program,
   path: PathToNode,
   stopAt?: SyntaxType | SyntaxType[],
   returnEarly = false
 ):
   | {
-      node: T
+      node: DynamicNode | unknown[]
+      stopAtNode: T | null
       shallowPath: PathToNode
       deepPath: PathToNode
     }
   | Error {
-  let currentNode = node as any
-  let stopAtNode = null
+  let currentNode: DynamicNode | unknown[] = node
+  let stopAtNode: T | null = null
   let successfulPaths: PathToNode = []
   let pathsExplored: PathToNode = []
   for (const pathItem of path) {
-    if (typeof currentNode[pathItem[0]] !== 'object') {
-      if (stopAtNode) {
+    const pathIndex = pathItem[0]
+    let nextNode: unknown
+    if (currentNode && typeof pathIndex === 'number' && isArray(currentNode)) {
+      nextNode = currentNode[pathIndex]
+    }
+    if (
+      currentNode &&
+      typeof pathIndex === 'string' &&
+      typeof currentNode === 'object' &&
+      !isArray(currentNode)
+    ) {
+      nextNode = currentNode[pathIndex]
+    }
+    if (!isArray(nextNode) && !isAstNode(nextNode)) {
+      if (isAstNode(stopAtNode)) {
         return {
           node: stopAtNode,
+          stopAtNode,
           shallowPath: pathsExplored,
           deepPath: successfulPaths,
         }
       }
       return new Error('not an object')
     }
-    currentNode = currentNode?.[pathItem[0]]
+    currentNode = nextNode
     successfulPaths.push(pathItem)
     if (!stopAtNode) {
       pathsExplored.push(pathItem)
     }
-    if (
-      typeof stopAt !== 'undefined' &&
-      (Array.isArray(stopAt)
-        ? stopAt.includes(currentNode.type)
-        : currentNode.type === stopAt)
-    ) {
+    if (stopAt && isNodeType<T>(currentNode, stopAt)) {
       // it will match the deepest node of the type
       // instead of returning at the first match
       stopAtNode = currentNode
       if (returnEarly) {
         return {
           node: stopAtNode,
+          stopAtNode,
           shallowPath: pathsExplored,
           deepPath: successfulPaths,
         }
@@ -86,32 +133,104 @@ export function getNodeFromPath<T>(
   }
   return {
     node: stopAtNode || currentNode,
+    stopAtNode,
     shallowPath: pathsExplored,
     deepPath: successfulPaths,
   }
 }
 
+/**
+ * Returns the terminal node in the given path.  Like getNodeFromPath, but no
+ * stopAt parameter.
+ */
+export function getLastNodeFromPath(
+  node: Program,
+  path: PathToNode
+):
+  | {
+      node: DynamicNode | unknown[]
+    }
+  | Error {
+  const _result = getNodeFromPath<DynamicNode>(node, path)
+  if (err(_result)) return _result
+  return {
+    node: _result.node,
+  }
+}
+
+/**
+ * Returns the terminal node in the given path, and asserts that it's the given
+ * type.
+ */
+export function expectLastNodeFromPath<T extends DynamicNode>(
+  node: Program,
+  path: PathToNode,
+  syntaxType: SyntaxType | SyntaxType[]
+): T | Error {
+  const result = getLastNodeFromPath(node, path)
+  if (err(result)) return result
+  if (!isNodeType<T>(result.node, syntaxType)) {
+    return new Error(
+      `Expected node of type ${syntaxType}: found ${JSON.stringify(result)}`
+    )
+  }
+
+  return result.node
+}
+
+/**
+ * Returns the node in the path with the given type.  Like getNodeFromPath, but
+ * if no stopAt node is found, an error is returned instead of null.
+ *
+ * @param {boolean} [options.firstFound=false] if true, return the first node of
+ *   the type found.  The default returns the last node found.
+ * @param {boolean} [options.message] the error message to return if the node is
+ *   not found.
+ */
+export function expectNodeOnPath<T extends DynamicNode>(
+  node: Program,
+  path: PathToNode,
+  syntaxType: SyntaxType,
+  options: { firstFound?: boolean; message?: string } = {
+    firstFound: false,
+  }
+): T | Error {
+  const result = getNodeFromPath<T>(node, path, syntaxType, options.firstFound)
+  if (err(result)) return result
+  if (!result.stopAtNode) {
+    return new Error(
+      options.message ?? `Node of type ${syntaxType} not found in path`
+    )
+  }
+  return result.stopAtNode
+}
+
 /**
  * Functions the same as getNodeFromPath, but returns a curried function that can be called with the stopAt and returnEarly arguments.
  */
 export function getNodeFromPathCurry(
   node: Program,
   path: PathToNode
-): <T>(
-  stopAt?: SyntaxType | SyntaxType[],
+): <T extends DynamicNode>(
+  stopAt: SyntaxType | SyntaxType[],
   returnEarly?: boolean
 ) =>
   | {
-      node: T
+      node: DynamicNode | unknown[]
+      stopAtNode: T | null
       path: PathToNode
     }
   | Error {
-  return <T>(stopAt?: SyntaxType | SyntaxType[], returnEarly = false) => {
+  return <T extends DynamicNode>(
+    stopAt: SyntaxType | SyntaxType[],
+    returnEarly = false
+  ) => {
     const _node1 = getNodeFromPath<T>(node, path, stopAt, returnEarly)
     if (err(_node1)) return _node1
-    const { node: _node, shallowPath } = _node1
+    const { node: _node, stopAtNode, shallowPath } = _node1
     return {
       node: _node,
+      stopAtNode,
       path: shallowPath,
     }
   }
@@ -459,7 +578,7 @@ export function findAllPreviousVariablesPath(
 
   const { index: insertIndex, path: bodyPath } = splitPathAtLastIndex(pathToDec)
 
-  const _node2 = getNodeFromPath<Program['body']>(ast, bodyPath)
+  const _node2 = getLastNodeFromPath(ast, bodyPath)
   if (err(_node2)) {
     console.error(_node2)
     return {
@@ -468,19 +587,30 @@ export function findAllPreviousVariablesPath(
       insertIndex: 0,
     }
   }
+  if (!isArray(_node2.node)) {
+    console.error(
+      `Expected node of type array, but found: ${JSON.stringify(_node2)}`
+    )
+    return {
+      variables: [],
+      bodyPath: [],
+      insertIndex: 0,
+    }
+  }
   const { node: bodyItems } = _node2
 
   const variables: PrevVariable<any>[] = []
-  bodyItems?.forEach?.((item) => {
-    if (item.type !== 'VariableDeclaration' || item.end > startRange) return
+  for (const unknownItem of bodyItems) {
+    const item = unknownItem as BodyItem
+    if (item.type !== 'VariableDeclaration' || item.end > startRange) continue
     const varName = item.declarations[0].id.name
     const varValue = programMemory?.get(varName)
-    if (!varValue || typeof varValue?.value !== type) return
+    if (!varValue || typeof varValue?.value !== type) continue
     variables.push({
       key: varName,
       value: varValue.value,
     })
-  })
+  }
 
   return {
     insertIndex,
@@ -554,7 +684,7 @@ export function isNodeSafeToReplacePath(
     }
     pathToReplaced[1][0] = index + 1
     const startPath = finPath.slice(0, -1)
-    const _nodeToReplace = getNodeFromPath(_ast, startPath)
+    const _nodeToReplace = getLastNodeFromPath(_ast, startPath)
     if (err(_nodeToReplace)) return _nodeToReplace
     const nodeToReplace = _nodeToReplace.node as any
     nodeToReplace[last[0]] = identifier
@@ -656,7 +786,8 @@ export function isLinesParallelAndConstrained(
       'CallExpression'
     )
     if (err(_secondaryNode)) return _secondaryNode
-    const secondaryNode = _secondaryNode.node
+    const secondaryNode = _secondaryNode.stopAtNode
+    if (!secondaryNode) return new Error('no secondary node found')
     const _varDec = getNodeFromPath(ast, primaryPath, 'VariableDeclaration')
     if (err(_varDec)) return _varDec
     const varDec = _varDec.node
@@ -682,7 +813,7 @@ export function isLinesParallelAndConstrained(
       Math.abs(primaryAngle - secondaryAngle) < EPSILON ||
       Math.abs(primaryAngle - secondaryAngleAlt) < EPSILON
 
-    // is secordary line fully constrain, or has constrain type of 'angle'
+    // is secondary line fully constrain, or has constrain type of 'angle'
     const secondaryFirstArg = getFirstArg(secondaryNode)
     if (err(secondaryFirstArg)) return secondaryFirstArg
 
@@ -747,8 +878,8 @@ export function doesPipeHaveCallExp({
     console.error(pipeExpressionMeta)
     return false
   }
-  const pipeExpression = pipeExpressionMeta.node
-  if (pipeExpression.type !== 'PipeExpression') return false
+  const pipeExpression = pipeExpressionMeta.stopAtNode
+  if (!pipeExpression) return false
   return pipeExpression.body.some(
     (expression) =>
       expression.type === 'CallExpression' &&
@@ -775,8 +906,8 @@ export function hasExtrudeSketchGroup({
     console.error(varDecMeta)
     return false
   }
-  const varDec = varDecMeta.node
-  if (varDec.type !== 'VariableDeclaration') return false
+  const varDec = varDecMeta.stopAtNode
+  if (!varDec) return false
   const varName = varDec.declarations[0].id.name
   const varValue = programMemory?.get(varName)
   return varValue?.type === 'ExtrudeGroup' || varValue?.type === 'SketchGroup'
@@ -814,8 +945,8 @@ export function findUsesOfTagInPipe(
     console.error(nodeMeta)
     return []
   }
-  const node = nodeMeta.node
-  if (node.type !== 'CallExpression') return []
+  const node = nodeMeta.stopAtNode
+  if (!node) return []
   const tagIndex = node.callee.name === 'close' ? 1 : 2
   const thirdParam = node.arguments[tagIndex]
   if (
@@ -836,9 +967,14 @@ export function findUsesOfTagInPipe(
     console.error(varDec)
     return []
   }
+  const varDecNode = varDec.stopAtNode
+  if (!varDecNode) {
+    console.error('varDecNode not found')
+    return []
+  }
   const dependentRanges: SourceRange[] = []
 
-  traverse(varDec.node, {
+  traverse(varDecNode, {
     enter: (node) => {
       if (
         node.type !== 'CallExpression' ||
@@ -860,16 +996,16 @@ export function hasSketchPipeBeenExtruded(selection: Selection, ast: Program) {
   const path = getNodePathFromSourceRange(ast, selection.range)
   const _node = getNodeFromPath<PipeExpression>(ast, path, 'PipeExpression')
   if (err(_node)) return false
-  const { node: pipeExpression } = _node
-  if (pipeExpression.type !== 'PipeExpression') return false
+  const { stopAtNode: pipeExpression } = _node
+  if (!pipeExpression) return false
   const _varDec = getNodeFromPath<VariableDeclarator>(
     ast,
     path,
     'VariableDeclarator'
   )
   if (err(_varDec)) return false
-  const varDec = _varDec.node
-  if (varDec.type !== 'VariableDeclarator') return false
+  const varDec = _varDec.stopAtNode
+  if (!varDec) return false
   let extruded = false
   traverse(ast as any, {
     enter(node) {

src/lang/std/sketch.test.ts

@@ -14,7 +14,11 @@ import {
   SourceRange,
   CallExpression,
 } from '../wasm'
-import { getNodeFromPath, getNodePathFromSourceRange } from '../queryAst'
+import {
+  expectNodeOnPath,
+  getNodeFromPath,
+  getNodePathFromSourceRange,
+} from '../queryAst'
 import { enginelessExecutor } from '../../lib/testHelpers'
 import { err } from 'lib/trap'
 
@@ -600,13 +604,13 @@ describe('testing getConstraintInfo', () => {
       ]
       if (err(ast)) return ast
       const pathToNode = getNodePathFromSourceRange(ast, sourceRange)
-      const callExp = getNodeFromPath<CallExpression>(
+      const callExp = expectNodeOnPath<CallExpression>(
         ast,
         pathToNode,
         'CallExpression'
       )
       if (err(callExp)) return callExp
-      const result = getConstraintInfo(callExp.node, code, pathToNode)
+      const result = getConstraintInfo(callExp, code, pathToNode)
       expect(result).toEqual(expected)
     })
   })
@@ -754,13 +758,13 @@ describe('testing getConstraintInfo', () => {
       ]
       if (err(ast)) return ast
       const pathToNode = getNodePathFromSourceRange(ast, sourceRange)
-      const callExp = getNodeFromPath<CallExpression>(
+      const callExp = expectNodeOnPath<CallExpression>(
         ast,
         pathToNode,
         'CallExpression'
       )
       if (err(callExp)) return callExp
-      const result = getConstraintInfo(callExp.node, code, pathToNode)
+      const result = getConstraintInfo(callExp, code, pathToNode)
       expect(result).toEqual(expected)
     })
   })
@@ -1110,14 +1114,14 @@ describe('testing getConstraintInfo', () => {
       ]
       if (err(ast)) return ast
       const pathToNode = getNodePathFromSourceRange(ast, sourceRange)
-      const callExp = getNodeFromPath<CallExpression>(
+      const callExp = expectNodeOnPath<CallExpression>(
         ast,
         pathToNode,
         'CallExpression'
       )
       if (err(callExp)) return callExp
 
-      const result = getConstraintInfo(callExp.node, code, pathToNode)
+      const result = getConstraintInfo(callExp, code, pathToNode)
       expect(result).toEqual(expected)
     })
   })

src/lang/std/sketch.ts

@@ -14,8 +14,10 @@ import {
   Identifier,
 } from 'lang/wasm'
 import {
+  isNodeType,
+  expectLastNodeFromPath,
+  expectNodeOnPath,
   getNodeFromPath,
-  getNodeFromPathCurry,
   getNodePathFromSourceRange,
 } from 'lang/queryAst'
 import {
@@ -50,7 +52,7 @@ import {
   mutateObjExpProp,
   findUniqueName,
 } from 'lang/modifyAst'
-import { roundOff, getLength, getAngle } from 'lib/utils'
+import { roundOff, getLength, getAngle, isArray } from 'lib/utils'
 import { err } from 'lib/trap'
 import { perpendicularDistance } from 'sketch-helpers'
 import { TagDeclarator } from 'wasm-lib/kcl/bindings/TagDeclarator'
@@ -330,13 +332,12 @@ export const lineTo: SketchLineHelper = {
     referencedSegment,
   }) => {
     const _node = { ...node }
-    const nodeMeta = getNodeFromPath<PipeExpression>(
+    const pipe = expectNodeOnPath<PipeExpression>(
       _node,
       pathToNode,
       'PipeExpression'
     )
-    if (err(nodeMeta)) return nodeMeta
-    const { node: pipe } = nodeMeta
+    if (err(pipe)) return pipe
 
     const newVals: [Value, Value] = [
       createLiteral(roundOff(to[0], 2)),
@@ -373,7 +374,7 @@ export const lineTo: SketchLineHelper = {
   },
   updateArgs: ({ node, pathToNode, to }) => {
     const _node = { ...node }
-    const nodeMeta = getNodeFromPath<CallExpression>(_node, pathToNode)
+    const nodeMeta = getNodeFromPath(_node, pathToNode)
     if (err(nodeMeta)) return nodeMeta
     const { node: callExpression } = nodeMeta
 
@@ -382,8 +383,13 @@ export const lineTo: SketchLineHelper = {
       createLiteral(to[1]),
     ])
 
-    mutateArrExp(callExpression.arguments?.[0], toArrExp) ||
-      mutateObjExpProp(callExpression.arguments?.[0], toArrExp, 'to')
+    if (isNodeType<CallExpression>(callExpression, 'CallExpression')) {
+      const firstArg = callExpression.arguments[0]
+      if (firstArg) {
+        mutateArrExp(firstArg, toArrExp) ||
+          mutateObjExpProp(firstArg, toArrExp, 'to')
+      }
+    }
     return {
       modifiedAst: _node,
       pathToNode,
@@ -414,7 +420,7 @@ export const line: SketchLineHelper = {
     spliceBetween,
   }) => {
     const _node = { ...node }
-    const nodeMeta = getNodeFromPath<PipeExpression | CallExpression>(
+    const nodeMeta = getNodeFromPath<PipeExpression>(
       _node,
       pathToNode,
       'PipeExpression'
@@ -427,12 +433,16 @@ export const line: SketchLineHelper = {
       'VariableDeclarator'
     )
     if (err(nodeMeta2)) return nodeMeta2
-    const { node: varDec } = nodeMeta2
+    const { stopAtNode: varDec } = nodeMeta2
 
     const newXVal = createLiteral(roundOff(to[0] - from[0], 2))
     const newYVal = createLiteral(roundOff(to[1] - from[1], 2))
 
-    if (spliceBetween && !createCallback && pipe.type === 'PipeExpression') {
+    if (
+      spliceBetween &&
+      !createCallback &&
+      isNodeType<PipeExpression>(pipe, 'PipeExpression')
+    ) {
       const callExp = createCallExpression('line', [
         createArrayExpression([newXVal, newYVal]),
         createPipeSubstitution(),
@@ -455,7 +465,11 @@ export const line: SketchLineHelper = {
       }
     }
 
-    if (replaceExisting && createCallback && pipe.type !== 'CallExpression') {
+    if (
+      replaceExisting &&
+      createCallback &&
+      isNodeType<PipeExpression>(pipe, 'PipeExpression')
+    ) {
       const { index: callIndex } = splitPathAtPipeExpression(pathToNode)
       const { callExp, valueUsedInTransform } = createCallback(
         [newXVal, newYVal],
@@ -477,7 +491,7 @@ export const line: SketchLineHelper = {
       createArrayExpression([newXVal, newYVal]),
       createPipeSubstitution(),
     ])
-    if (pipe.type === 'PipeExpression') {
+    if (isNodeType<PipeExpression>(pipe, 'PipeExpression')) {
       pipe.body = [...pipe.body, callExp]
       return {
         modifiedAst: _node,
@@ -488,6 +502,7 @@ export const line: SketchLineHelper = {
         ],
       }
     } else {
+      if (!varDec) return new Error('Variable declaration not found')
       varDec.init = createPipeExpression([varDec.init, callExp])
     }
     return {
@@ -497,7 +512,11 @@ export const line: SketchLineHelper = {
   },
   updateArgs: ({ node, pathToNode, to, from }) => {
     const _node = { ...node }
-    const nodeMeta = getNodeFromPath<CallExpression>(_node, pathToNode)
+    const nodeMeta = getNodeFromPath<CallExpression>(
+      _node,
+      pathToNode,
+      'CallExpression'
+    )
     if (err(nodeMeta)) return nodeMeta
     const { node: callExpression } = nodeMeta
 
@@ -506,10 +525,15 @@ export const line: SketchLineHelper = {
       createLiteral(roundOff(to[1] - from[1], 2)),
     ])
 
-    if (callExpression.arguments?.[0].type === 'ObjectExpression') {
-      mutateObjExpProp(callExpression.arguments?.[0], toArrExp, 'to')
-    } else {
-      mutateArrExp(callExpression.arguments?.[0], toArrExp)
+    if (isNodeType<CallExpression>(callExpression, 'CallExpression')) {
+      const firstArg = callExpression.arguments[0]
+      if (firstArg) {
+        if (firstArg.type === 'ObjectExpression') {
+          mutateObjExpProp(firstArg, toArrExp, 'to')
+        } else {
+          mutateArrExp(firstArg, toArrExp)
+        }
+      }
     }
     return {
       modifiedAst: _node,
@@ -531,10 +555,12 @@ export const line: SketchLineHelper = {
 export const xLineTo: SketchLineHelper = {
   add: ({ node, pathToNode, to, replaceExisting, createCallback }) => {
     const _node = { ...node }
-    const getNode = getNodeFromPathCurry(_node, pathToNode)
-    const _node1 = getNode<PipeExpression>('PipeExpression')
-    if (err(_node1)) return _node1
-    const { node: pipe } = _node1
+    const pipe = expectLastNodeFromPath<PipeExpression>(
+      _node,
+      pathToNode,
+      'PipeExpression'
+    )
+    if (err(pipe)) return pipe
 
     const newVal = createLiteral(roundOff(to[0], 2))
 
@@ -563,14 +589,24 @@ export const xLineTo: SketchLineHelper = {
   },
   updateArgs: ({ node, pathToNode, to }) => {
     const _node = { ...node }
-    const nodeMeta = getNodeFromPath<CallExpression>(_node, pathToNode)
+    const nodeMeta = getNodeFromPath<CallExpression>(
+      _node,
+      pathToNode,
+      'CallExpression'
+    )
     if (err(nodeMeta)) return nodeMeta
     const { node: callExpression } = nodeMeta
-    const newX = createLiteral(roundOff(to[0], 2))
-    if (isLiteralArrayOrStatic(callExpression.arguments?.[0])) {
-      callExpression.arguments[0] = newX
-    } else {
-      mutateObjExpProp(callExpression.arguments?.[0], newX, 'to')
+
+    if (isNodeType<CallExpression>(callExpression, 'CallExpression')) {
+      const firstArg = callExpression.arguments[0]
+      if (firstArg) {
+        const newX = createLiteral(roundOff(to[0], 2))
+        if (isLiteralArrayOrStatic(firstArg)) {
+          callExpression.arguments[0] = newX
+        } else {
+          mutateObjExpProp(firstArg, newX, 'to')
+        }
+      }
     }
     return {
       modifiedAst: _node,
@@ -592,10 +628,12 @@ export const xLineTo: SketchLineHelper = {
 export const yLineTo: SketchLineHelper = {
   add: ({ node, pathToNode, to, replaceExisting, createCallback }) => {
     const _node = { ...node }
-    const getNode = getNodeFromPathCurry(_node, pathToNode)
-    const _node1 = getNode<PipeExpression>('PipeExpression')
-    if (err(_node1)) return _node1
-    const { node: pipe } = _node1
+    const pipe = expectLastNodeFromPath<PipeExpression>(
+      _node,
+      pathToNode,
+      'PipeExpression'
+    )
+    if (err(pipe)) return pipe
 
     const newVal = createLiteral(roundOff(to[1], 2))
 
@@ -624,14 +662,24 @@ export const yLineTo: SketchLineHelper = {
   },
   updateArgs: ({ node, pathToNode, to, from }) => {
     const _node = { ...node }
-    const nodeMeta = getNodeFromPath<CallExpression>(_node, pathToNode)
+    const nodeMeta = getNodeFromPath<CallExpression>(
+      _node,
+      pathToNode,
+      'CallExpression'
+    )
     if (err(nodeMeta)) return nodeMeta
     const { node: callExpression } = nodeMeta
-    const newY = createLiteral(roundOff(to[1], 2))
-    if (isLiteralArrayOrStatic(callExpression.arguments?.[0])) {
-      callExpression.arguments[0] = newY
-    } else {
-      mutateObjExpProp(callExpression.arguments?.[0], newY, 'to')
+
+    if (isNodeType<CallExpression>(callExpression, 'CallExpression')) {
+      const firstArg = callExpression.arguments[0]
+      if (firstArg) {
+        const newY = createLiteral(roundOff(to[1], 2))
+        if (isLiteralArrayOrStatic(firstArg)) {
+          callExpression.arguments[0] = newY
+        } else {
+          mutateObjExpProp(firstArg, newY, 'to')
+        }
+      }
     }
     return {
       modifiedAst: _node,
@@ -653,10 +701,12 @@ export const yLineTo: SketchLineHelper = {
 export const xLine: SketchLineHelper = {
   add: ({ node, pathToNode, to, from, replaceExisting, createCallback }) => {
     const _node = { ...node }
-    const getNode = getNodeFromPathCurry(_node, pathToNode)
-    const _node1 = getNode<PipeExpression>('PipeExpression')
-    if (err(_node1)) return _node1
-    const { node: pipe } = _node1
+    const pipe = expectNodeOnPath<PipeExpression>(
+      _node,
+      pathToNode,
+      'PipeExpression'
+    )
+    if (err(pipe)) return pipe
 
     const newVal = createLiteral(roundOff(to[0] - from[0], 2))
     const firstArg = newVal
@@ -684,14 +734,24 @@ export const xLine: SketchLineHelper = {
   },
   updateArgs: ({ node, pathToNode, to, from }) => {
     const _node = { ...node }
-    const nodeMeta = getNodeFromPath<CallExpression>(_node, pathToNode)
+    const nodeMeta = getNodeFromPath<CallExpression>(
+      _node,
+      pathToNode,
+      'CallExpression'
+    )
     if (err(nodeMeta)) return nodeMeta
     const { node: callExpression } = nodeMeta
-    const newX = createLiteral(roundOff(to[0] - from[0], 2))
-    if (isLiteralArrayOrStatic(callExpression.arguments?.[0])) {
-      callExpression.arguments[0] = newX
-    } else {
-      mutateObjExpProp(callExpression.arguments?.[0], newX, 'length')
+
+    if (isNodeType<CallExpression>(callExpression, 'CallExpression')) {
+      const firstArg = callExpression.arguments[0]
+      if (firstArg) {
+        const newX = createLiteral(roundOff(to[0] - from[0], 2))
+        if (isLiteralArrayOrStatic(firstArg)) {
+          callExpression.arguments[0] = newX
+        } else {
+          mutateObjExpProp(firstArg, newX, 'length')
+        }
+      }
     }
     return {
       modifiedAst: _node,
@@ -713,10 +773,12 @@ export const xLine: SketchLineHelper = {
 export const yLine: SketchLineHelper = {
   add: ({ node, pathToNode, to, from, replaceExisting, createCallback }) => {
     const _node = { ...node }
-    const getNode = getNodeFromPathCurry(_node, pathToNode)
-    const _node1 = getNode<PipeExpression>('PipeExpression')
-    if (err(_node1)) return _node1
-    const { node: pipe } = _node1
+    const pipe = expectNodeOnPath<PipeExpression>(
+      _node,
+      pathToNode,
+      'PipeExpression'
+    )
+    if (err(pipe)) return pipe
     const newVal = createLiteral(roundOff(to[1] - from[1], 2))
     if (replaceExisting && createCallback) {
       const { index: callIndex } = splitPathAtPipeExpression(pathToNode)
@@ -741,14 +803,24 @@ export const yLine: SketchLineHelper = {
   },
   updateArgs: ({ node, pathToNode, to, from }) => {
     const _node = { ...node }
-    const nodeMeta = getNodeFromPath<CallExpression>(_node, pathToNode)
+    const nodeMeta = getNodeFromPath<CallExpression>(
+      _node,
+      pathToNode,
+      'CallExpression'
+    )
     if (err(nodeMeta)) return nodeMeta
     const { node: callExpression } = nodeMeta
-    const newY = createLiteral(roundOff(to[1] - from[1], 2))
-    if (isLiteralArrayOrStatic(callExpression.arguments?.[0])) {
-      callExpression.arguments[0] = newY
-    } else {
-      mutateObjExpProp(callExpression.arguments?.[0], newY, 'length')
+
+    if (isNodeType<CallExpression>(callExpression, 'CallExpression')) {
+      const firstArg = callExpression.arguments[0]
+      if (firstArg) {
+        const newY = createLiteral(roundOff(to[1] - from[1], 2))
+        if (isLiteralArrayOrStatic(firstArg)) {
+          callExpression.arguments[0] = newY
+        } else {
+          mutateObjExpProp(firstArg, newY, 'length')
+        }
+      }
     }
     return {
       modifiedAst: _node,
@@ -777,8 +849,11 @@ export const tangentialArcTo: SketchLineHelper = {
     referencedSegment,
   }) => {
     const _node = { ...node }
-    const getNode = getNodeFromPathCurry(_node, pathToNode)
-    const _node1 = getNode<PipeExpression | CallExpression>('PipeExpression')
+    const _node1 = getNodeFromPath<PipeExpression>(
+      _node,
+      pathToNode,
+      'PipeExpression'
+    )
     if (err(_node1)) return _node1
     const { node: pipe } = _node1
     const _node2 = getNodeFromPath<VariableDeclarator>(
@@ -787,12 +862,16 @@ export const tangentialArcTo: SketchLineHelper = {
       'VariableDeclarator'
     )
     if (err(_node2)) return _node2
-    const { node: varDec } = _node2
+    const { stopAtNode: varDec } = _node2
 
     const toX = createLiteral(roundOff(to[0], 2))
     const toY = createLiteral(roundOff(to[1], 2))
 
-    if (replaceExisting && createCallback && pipe.type !== 'CallExpression') {
+    if (
+      replaceExisting &&
+      createCallback &&
+      isNodeType<PipeExpression>(pipe, 'PipeExpression')
+    ) {
       const { index: callIndex } = splitPathAtPipeExpression(pathToNode)
       const { callExp, valueUsedInTransform } = createCallback(
         [toX, toY],
@@ -813,7 +892,7 @@ export const tangentialArcTo: SketchLineHelper = {
       createArrayExpression([toX, toY]),
       createPipeSubstitution(),
     ])
-    if (pipe.type === 'PipeExpression') {
+    if (isNodeType<PipeExpression>(pipe, 'PipeExpression')) {
       pipe.body = [...pipe.body, newLine]
       return {
         modifiedAst: _node,
@@ -824,6 +903,7 @@ export const tangentialArcTo: SketchLineHelper = {
         ],
       }
     } else {
+      if (!varDec) return new Error('Variable declaration not found')
       varDec.init = createPipeExpression([varDec.init, newLine])
     }
     return {
@@ -833,15 +913,23 @@ export const tangentialArcTo: SketchLineHelper = {
   },
   updateArgs: ({ node, pathToNode, to, from }) => {
     const _node = { ...node }
-    const nodeMeta = getNodeFromPath<CallExpression>(_node, pathToNode)
+    const nodeMeta = getNodeFromPath<CallExpression>(
+      _node,
+      pathToNode,
+      'CallExpression'
+    )
     if (err(nodeMeta)) return nodeMeta
     const { node: callExpression } = nodeMeta
     const x = createLiteral(roundOff(to[0], 2))
     const y = createLiteral(roundOff(to[1], 2))
 
-    const firstArg = callExpression.arguments?.[0]
-    if (!mutateArrExp(firstArg, createArrayExpression([x, y]))) {
-      mutateObjExpProp(firstArg, createArrayExpression([x, y]), 'to')
+    if (isNodeType<CallExpression>(callExpression, 'CallExpression')) {
+      const firstArg = callExpression.arguments[0]
+      if (firstArg) {
+        if (!mutateArrExp(firstArg, createArrayExpression([x, y]))) {
+          mutateObjExpProp(firstArg, createArrayExpression([x, y]), 'to')
+        }
+      }
     }
     return {
       modifiedAst: _node,
@@ -909,10 +997,12 @@ export const angledLine: SketchLineHelper = {
     referencedSegment,
   }) => {
     const _node = { ...node }
-    const getNode = getNodeFromPathCurry(_node, pathToNode)
-    const _node1 = getNode<PipeExpression>('PipeExpression')
-    if (err(_node1)) return _node1
-    const { node: pipe } = _node1
+    const pipe = expectNodeOnPath<PipeExpression>(
+      _node,
+      pathToNode,
+      'PipeExpression'
+    )
+    if (err(pipe)) return pipe
 
     const newAngleVal = createLiteral(roundOff(getAngle(from, to), 0))
     const newLengthVal = createLiteral(roundOff(getLength(from, to), 2))
@@ -947,7 +1037,11 @@ export const angledLine: SketchLineHelper = {
   },
   updateArgs: ({ node, pathToNode, to, from }) => {
     const _node = { ...node }
-    const nodeMeta = getNodeFromPath<CallExpression>(_node, pathToNode)
+    const nodeMeta = getNodeFromPath<CallExpression>(
+      _node,
+      pathToNode,
+      'CallExpression'
+    )
     if (err(nodeMeta)) return nodeMeta
     const { node: callExpression } = nodeMeta
     const angle = roundOff(getAngle(from, to), 0)
@@ -956,10 +1050,16 @@ export const angledLine: SketchLineHelper = {
     const angleLit = createLiteral(angle)
     const lengthLit = createLiteral(lineLength)
 
-    const firstArg = callExpression.arguments?.[0]
-    if (!mutateArrExp(firstArg, createArrayExpression([angleLit, lengthLit]))) {
-      mutateObjExpProp(firstArg, angleLit, 'angle')
-      mutateObjExpProp(firstArg, lengthLit, 'length')
+    if (isNodeType<CallExpression>(callExpression, 'CallExpression')) {
+      const firstArg = callExpression.arguments[0]
+      if (firstArg) {
+        if (
+          !mutateArrExp(firstArg, createArrayExpression([angleLit, lengthLit]))
+        ) {
+          mutateObjExpProp(firstArg, angleLit, 'angle')
+          mutateObjExpProp(firstArg, lengthLit, 'length')
+        }
+      }
     }
 
     return {
@@ -993,20 +1093,18 @@ export const angledLineOfXLength: SketchLineHelper = {
     replaceExisting,
   }) => {
     const _node = { ...node }
-    const nodeMeta = getNodeFromPath<PipeExpression>(
+    const pipe = expectNodeOnPath<PipeExpression>(
       _node,
       pathToNode,
       'PipeExpression'
     )
-    if (err(nodeMeta)) return nodeMeta
-    const { node: pipe } = nodeMeta
-    const nodeMeta2 = getNodeFromPath<VariableDeclarator>(
+    if (err(pipe)) return pipe
+    const varDec = expectNodeOnPath<VariableDeclarator>(
       _node,
       pathToNode,
       'VariableDeclarator'
     )
-    if (err(nodeMeta2)) return nodeMeta2
-    const { node: varDec } = nodeMeta2
+    if (err(varDec)) return varDec
 
     const variableName = varDec.id.name
     const sketch = previousProgramMemory?.get(variableName)
@@ -1040,23 +1138,33 @@ export const angledLineOfXLength: SketchLineHelper = {
   },
   updateArgs: ({ node, pathToNode, to, from }) => {
     const _node = { ...node }
-    const nodeMeta = getNodeFromPath<CallExpression>(_node, pathToNode)
+    const nodeMeta = getNodeFromPath<CallExpression>(
+      _node,
+      pathToNode,
+      'CallExpression'
+    )
     if (err(nodeMeta)) return nodeMeta
     const { node: callExpression } = nodeMeta
     const angle = roundOff(getAngle(from, to), 0)
     const xLength = roundOff(Math.abs(to[0] - from[0]), 2)
 
-    const firstArg = callExpression.arguments?.[0]
-    const adjustedXLength = isAngleLiteral(firstArg)
-      ? Math.abs(xLength)
-      : xLength // todo make work for variable angle > 180
+    if (isNodeType<CallExpression>(callExpression, 'CallExpression')) {
+      const firstArg = callExpression.arguments[0]
+      if (firstArg) {
+        const adjustedXLength = isAngleLiteral(firstArg)
+          ? Math.abs(xLength)
+          : xLength // todo make work for variable angle > 180
 
-    const angleLit = createLiteral(angle)
-    const lengthLit = createLiteral(adjustedXLength)
+        const angleLit = createLiteral(angle)
+        const lengthLit = createLiteral(adjustedXLength)
 
-    if (!mutateArrExp(firstArg, createArrayExpression([angleLit, lengthLit]))) {
-      mutateObjExpProp(firstArg, angleLit, 'angle')
-      mutateObjExpProp(firstArg, lengthLit, 'length')
+        if (
+          !mutateArrExp(firstArg, createArrayExpression([angleLit, lengthLit]))
+        ) {
+          mutateObjExpProp(firstArg, angleLit, 'angle')
+          mutateObjExpProp(firstArg, lengthLit, 'length')
+        }
+      }
     }
 
     return {
@@ -1090,20 +1198,18 @@ export const angledLineOfYLength: SketchLineHelper = {
     replaceExisting,
   }) => {
     const _node = { ...node }
-    const nodeMeta = getNodeFromPath<PipeExpression>(
+    const pipe = expectNodeOnPath<PipeExpression>(
       _node,
       pathToNode,
       'PipeExpression'
     )
-    if (err(nodeMeta)) return nodeMeta
-    const { node: pipe } = nodeMeta
-    const nodeMeta2 = getNodeFromPath<VariableDeclarator>(
+    if (err(pipe)) return pipe
+    const varDec = expectNodeOnPath<VariableDeclarator>(
       _node,
       pathToNode,
       'VariableDeclarator'
     )
-    if (err(nodeMeta2)) return nodeMeta2
-    const { node: varDec } = nodeMeta2
+    if (err(varDec)) return varDec
     const variableName = varDec.id.name
     const sketch = previousProgramMemory?.get(variableName)
     if (!sketch || sketch.type !== 'SketchGroup') {
@@ -1137,23 +1243,33 @@ export const angledLineOfYLength: SketchLineHelper = {
   },
   updateArgs: ({ node, pathToNode, to, from }) => {
     const _node = { ...node }
-    const nodeMeta = getNodeFromPath<CallExpression>(_node, pathToNode)
+    const nodeMeta = getNodeFromPath<CallExpression>(
+      _node,
+      pathToNode,
+      'CallExpression'
+    )
     if (err(nodeMeta)) return nodeMeta
     const { node: callExpression } = nodeMeta
     const angle = roundOff(getAngle(from, to), 0)
     const yLength = roundOff(to[1] - from[1], 2)
 
-    const firstArg = callExpression.arguments?.[0]
-    const adjustedYLength = isAngleLiteral(firstArg)
-      ? Math.abs(yLength)
-      : yLength // todo make work for variable angle > 180
+    if (isNodeType<CallExpression>(callExpression, 'CallExpression')) {
+      const firstArg = callExpression.arguments[0]
+      if (firstArg) {
+        const adjustedYLength = isAngleLiteral(firstArg)
+          ? Math.abs(yLength)
+          : yLength // todo make work for variable angle > 180
 
-    const angleLit = createLiteral(angle)
-    const lengthLit = createLiteral(adjustedYLength)
+        const angleLit = createLiteral(angle)
+        const lengthLit = createLiteral(adjustedYLength)
 
-    if (!mutateArrExp(firstArg, createArrayExpression([angleLit, lengthLit]))) {
-      mutateObjExpProp(firstArg, angleLit, 'angle')
-      mutateObjExpProp(firstArg, lengthLit, 'length')
+        if (
+          !mutateArrExp(firstArg, createArrayExpression([angleLit, lengthLit]))
+        ) {
+          mutateObjExpProp(firstArg, angleLit, 'angle')
+          mutateObjExpProp(firstArg, lengthLit, 'length')
+        }
+      }
     }
 
     return {
@@ -1187,14 +1303,13 @@ export const angledLineToX: SketchLineHelper = {
     referencedSegment,
   }) => {
     const _node = { ...node }
-    const nodeMeta = getNodeFromPath<PipeExpression>(
+    const pipe = expectNodeOnPath<PipeExpression>(
       _node,
       pathToNode,
       'PipeExpression'
     )
-    if (err(nodeMeta)) return nodeMeta
+    if (err(pipe)) return pipe
 
-    const { node: pipe } = nodeMeta
     const angle = createLiteral(roundOff(getAngle(from, to), 0))
     const xArg = createLiteral(roundOff(to[0], 2))
     if (replaceExisting && createCallback) {
@@ -1227,22 +1342,32 @@ export const angledLineToX: SketchLineHelper = {
   },
   updateArgs: ({ node, pathToNode, to, from }) => {
     const _node = { ...node }
-    const nodeMeta = getNodeFromPath<CallExpression>(_node, pathToNode)
+    const nodeMeta = getNodeFromPath<CallExpression>(
+      _node,
+      pathToNode,
+      'CallExpression'
+    )
     if (err(nodeMeta)) return nodeMeta
-
     const { node: callExpression } = nodeMeta
+
     const angle = roundOff(getAngle(from, to), 0)
     const xLength = roundOff(to[0], 2)
 
-    const firstArg = callExpression.arguments?.[0]
-    const adjustedXLength = xLength
+    if (isNodeType<CallExpression>(callExpression, 'CallExpression')) {
+      const firstArg = callExpression.arguments[0]
+      if (firstArg) {
+        const adjustedXLength = xLength
 
-    const angleLit = createLiteral(angle)
-    const lengthLit = createLiteral(adjustedXLength)
+        const angleLit = createLiteral(angle)
+        const lengthLit = createLiteral(adjustedXLength)
 
-    if (!mutateArrExp(firstArg, createArrayExpression([angleLit, lengthLit]))) {
-      mutateObjExpProp(firstArg, angleLit, 'angle')
-      mutateObjExpProp(firstArg, lengthLit, 'to')
+        if (
+          !mutateArrExp(firstArg, createArrayExpression([angleLit, lengthLit]))
+        ) {
+          mutateObjExpProp(firstArg, angleLit, 'angle')
+          mutateObjExpProp(firstArg, lengthLit, 'to')
+        }
+      }
     }
     return {
       modifiedAst: _node,
@@ -1275,14 +1400,12 @@ export const angledLineToY: SketchLineHelper = {
     referencedSegment,
   }) => {
     const _node = { ...node }
-    const nodeMeta = getNodeFromPath<PipeExpression>(
+    const pipe = expectNodeOnPath<PipeExpression>(
       _node,
       pathToNode,
       'PipeExpression'
     )
-    if (err(nodeMeta)) return nodeMeta
-
-    const { node: pipe } = nodeMeta
+    if (err(pipe)) return pipe
 
     const angle = createLiteral(roundOff(getAngle(from, to), 0))
     const yArg = createLiteral(roundOff(to[1], 2))
@@ -1317,22 +1440,32 @@ export const angledLineToY: SketchLineHelper = {
   },
   updateArgs: ({ node, pathToNode, to, from }) => {
     const _node = { ...node }
-    const nodeMeta = getNodeFromPath<CallExpression>(_node, pathToNode)
+    const nodeMeta = getNodeFromPath<CallExpression>(
+      _node,
+      pathToNode,
+      'CallExpression'
+    )
     if (err(nodeMeta)) return nodeMeta
-
     const { node: callExpression } = nodeMeta
+
     const angle = roundOff(getAngle(from, to), 0)
     const xLength = roundOff(to[1], 2)
 
-    const firstArg = callExpression.arguments?.[0]
-    const adjustedXLength = xLength
+    if (isNodeType<CallExpression>(callExpression, 'CallExpression')) {
+      const firstArg = callExpression.arguments[0]
+      if (firstArg) {
+        const adjustedXLength = xLength
 
-    const angleLit = createLiteral(angle)
-    const lengthLit = createLiteral(adjustedXLength)
+        const angleLit = createLiteral(angle)
+        const lengthLit = createLiteral(adjustedXLength)
 
-    if (!mutateArrExp(firstArg, createArrayExpression([angleLit, lengthLit]))) {
-      mutateObjExpProp(firstArg, angleLit, 'angle')
-      mutateObjExpProp(firstArg, lengthLit, 'to')
+        if (
+          !mutateArrExp(firstArg, createArrayExpression([angleLit, lengthLit]))
+        ) {
+          mutateObjExpProp(firstArg, angleLit, 'angle')
+          mutateObjExpProp(firstArg, lengthLit, 'to')
+        }
+      }
     }
     return {
       modifiedAst: _node,
@@ -1372,7 +1505,7 @@ export const angledLineThatIntersects: SketchLineHelper = {
     )
     if (err(nodeMeta)) return nodeMeta
 
-    const { node: pipe } = nodeMeta
+    const { stopAtNode: pipe } = nodeMeta
 
     const angle = createLiteral(roundOff(getAngle(from, to), 0))
     if (!referencedSegment) {
@@ -1409,6 +1542,7 @@ export const angledLineThatIntersects: SketchLineHelper = {
         ]
       )
       const { index: callIndex } = splitPathAtPipeExpression(pathToNode)
+      if (!pipe) return new Error('Pipe expression not found')
       pipe.body[callIndex] = callExp
       return {
         modifiedAst: _node,
@@ -1420,10 +1554,13 @@ export const angledLineThatIntersects: SketchLineHelper = {
   },
   updateArgs: ({ node, pathToNode, to, from, previousProgramMemory }) => {
     const _node = { ...node }
-    const nodeMeta = getNodeFromPath<CallExpression>(_node, pathToNode)
-    if (err(nodeMeta)) return nodeMeta
+    const callExpression = expectLastNodeFromPath<CallExpression>(
+      _node,
+      pathToNode,
+      'CallExpression'
+    )
+    if (err(callExpression)) return callExpression
 
-    const { node: callExpression } = nodeMeta
     const angle = roundOff(getAngle(from, to), 0)
 
     const firstArg = callExpression.arguments?.[0]
@@ -1434,14 +1571,13 @@ export const angledLineThatIntersects: SketchLineHelper = {
         : createLiteral('')
     const intersectTagName =
       intersectTag.type === 'Identifier' ? intersectTag.name : ''
-    const nodeMeta2 = getNodeFromPath<VariableDeclaration>(
+    const varDec = expectNodeOnPath<VariableDeclaration>(
       _node,
       pathToNode,
       'VariableDeclaration'
     )
-    if (err(nodeMeta2)) return nodeMeta2
+    if (err(varDec)) return varDec
 
-    const { node: varDec } = nodeMeta2
     const varName = varDec.declarations[0].id.name
     const sketchGroup = previousProgramMemory.get(varName) as SketchGroup
     const intersectPath = sketchGroup.value.find(
@@ -1553,11 +1689,16 @@ export const updateStartProfileAtArgs: SketchLineHelper['updateArgs'] = ({
   to,
 }) => {
   const _node = { ...node }
-  const nodeMeta = getNodeFromPath<CallExpression>(_node, pathToNode)
-  if (err(nodeMeta)) {
-    console.error(nodeMeta)
+  const callExpression = expectLastNodeFromPath<CallExpression>(
+    _node,
+    pathToNode,
+    'CallExpression'
+  )
+  if (err(callExpression)) {
+    console.error(callExpression)
     return {
       modifiedAst: {
+        type: 'Program',
         start: 0,
         end: 0,
         body: [],
@@ -1572,7 +1713,6 @@ export const updateStartProfileAtArgs: SketchLineHelper['updateArgs'] = ({
     }
   }
 
-  const { node: callExpression } = nodeMeta
   const toArrExp = createArrayExpression([
     createLiteral(roundOff(to[0])),
     createLiteral(roundOff(to[1])),
@@ -1615,8 +1755,14 @@ export function changeSketchArguments(
   if (err(nodeMeta)) return nodeMeta
 
   const { node: callExpression, shallowPath } = nodeMeta
+  if (isArray(callExpression)) {
+    return new Error('Expected call expression but found array')
+  }
+  if (!isNodeType<CallExpression>(callExpression, 'CallExpression')) {
+    return new Error('Call expression not found')
+  }
 
-  if (callExpression?.callee?.name in sketchLineHelperMap) {
+  if (callExpression.callee.name in sketchLineHelperMap) {
     const { updateArgs } = sketchLineHelperMap[callExpression.callee.name]
     if (!updateArgs) {
       return new Error('not a sketch line helper')
@@ -1631,7 +1777,7 @@ export function changeSketchArguments(
     })
   }
 
-  return new Error(`not a sketch line helper: ${callExpression?.callee?.name}`)
+  return new Error(`not a sketch line helper: ${callExpression.callee.name}`)
 }
 
 export function getConstraintInfo(
@@ -1737,10 +1883,13 @@ export function addCallExpressionsToPipe({
   )
   if (err(pipeExpression)) return pipeExpression
 
-  if (pipeExpression.node.type !== 'PipeExpression') {
+  if (!pipeExpression.stopAtNode) {
     return new Error('not a pipe expression')
   }
-  pipeExpression.node.body = [...pipeExpression.node.body, ...expressions]
+  pipeExpression.stopAtNode.body = [
+    ...pipeExpression.stopAtNode.body,
+    ...expressions,
+  ]
   return _node
 }
 
@@ -1763,10 +1912,13 @@ export function addCloseToPipe({
   )
   if (err(pipeExpression)) return pipeExpression
 
-  if (pipeExpression.node.type !== 'PipeExpression') {
+  if (!pipeExpression.stopAtNode) {
     return new Error('not a pipe expression')
   }
-  pipeExpression.node.body = [...pipeExpression.node.body, closeExpression]
+  pipeExpression.stopAtNode.body = [
+    ...pipeExpression.stopAtNode.body,
+    closeExpression,
+  ]
   return _node
 }
 
@@ -1854,18 +2006,16 @@ type addTagFn = (a: AddTagInfo) => { modifiedAst: Program; tag: string } | Error
 function addTag(tagIndex = 2): addTagFn {
   return ({ node, pathToNode }) => {
     const _node = { ...node }
-    const callExpr = getNodeFromPath<CallExpression>(
+    const primaryCallExp = expectNodeOnPath<CallExpression>(
       _node,
       pathToNode,
       'CallExpression'
     )
-    if (err(callExpr)) return callExpr
-
-    const { node: primaryCallExp } = callExpr
+    if (err(primaryCallExp)) return primaryCallExp
 
     // Tag is always 3rd expression now, using arg index feels brittle
     // but we can come up with a better way to identify tag later.
-    const thirdArg = primaryCallExp.arguments?.[tagIndex]
+    const thirdArg = primaryCallExp.arguments[tagIndex]
     const tagDeclarator =
       thirdArg ||
       (createTagDeclarator(findUniqueName(_node, 'seg', 2)) as TagDeclarator)

src/lang/std/sketchConstraints.ts

@@ -1,4 +1,4 @@
-import { getNodeFromPath } from 'lang/queryAst'
+import { getLastNodeFromPath } from 'lang/queryAst'
 import { ToolTip, toolTips } from 'lang/langHelpers'
 import {
   Program,
@@ -8,9 +8,9 @@ import {
   SourceRange,
   Path,
   PathToNode,
-  Value,
 } from '../wasm'
 import { err } from 'lib/trap'
+import { isArray } from 'lib/utils'
 
 export function getSketchSegmentFromPathToNode(
   sketchGroup: SketchGroup,
@@ -25,11 +25,14 @@ export function getSketchSegmentFromPathToNode(
   // TODO: once pathTodNode is stored on program memory as part of execution,
   // we can check if the pathToNode matches the pathToNode of the sketchGroup.
   // For now we fall back to the sourceRange
-  const nodeMeta = getNodeFromPath<Value>(ast, pathToNode)
+  const nodeMeta = getLastNodeFromPath(ast, pathToNode)
   if (err(nodeMeta)) return nodeMeta
+  const { node } = nodeMeta
+  if (isArray(node)) {
+    return new Error('Value node expected, but found array')
+  }
 
-  const node = nodeMeta.node
-  if (!node || typeof node.start !== 'number' || !node.end)
+  if (typeof node.start !== 'number' || !node.end)
     return new Error('no node found')
   const sourceRange: SourceRange = [node.start, node.end]
   return getSketchSegmentFromSourceRange(sketchGroup, sourceRange)

src/lang/std/sketchcombos.ts

@@ -12,6 +12,9 @@ import {
   ProgramMemory,
 } from '../wasm'
 import {
+  isNodeType,
+  expectNodeOnPath,
+  getLastNodeFromPath,
   getNodeFromPath,
   getNodeFromPathCurry,
   getNodePathFromSourceRange,
@@ -39,7 +42,7 @@ import {
   getSketchSegmentFromPathToNode,
   getSketchSegmentFromSourceRange,
 } from './sketchConstraints'
-import { getAngle, roundOff, normaliseAngle } from '../../lib/utils'
+import { getAngle, roundOff, normaliseAngle, isArray } from '../../lib/utils'
 
 export type LineInputsType =
   | 'xAbsolute'
@@ -1225,22 +1228,19 @@ export function removeSingleConstraint({
   objectProperty?: string
   ast: Program
 }): TransformInfo | false {
-  const callExp = getNodeFromPath<CallExpression>(
+  const callExp = expectNodeOnPath<CallExpression>(
     ast,
     pathToCallExp,
-    'CallExpression'
+    'CallExpression',
+    { message: 'Invalid node type' }
   )
   if (err(callExp)) {
     console.error(callExp)
     return false
   }
-  if (callExp.node.type !== 'CallExpression') {
-    console.error(new Error('Invalid node type'))
-    return false
-  }
 
   const transform: TransformInfo = {
-    tooltip: callExp.node.callee.name as any,
+    tooltip: callExp.callee.name as any,
     createNode:
       ({ tag, referenceSegName, varValues }) =>
       (_, rawValues) => {
@@ -1264,7 +1264,7 @@ export function removeSingleConstraint({
           })
           const objExp = createObjectExpression(expression)
           return createStdlibCallExpression(
-            callExp.node.callee.name as any,
+            callExp.callee.name as any,
             objExp,
             tag
           )
@@ -1289,7 +1289,7 @@ export function removeSingleConstraint({
             return varValue.value
           })
           return createStdlibCallExpression(
-            callExp.node.callee.name as any,
+            callExp.callee.name as any,
             createArrayExpression(values),
             tag
           )
@@ -1298,7 +1298,7 @@ export function removeSingleConstraint({
         // if (typeof arrayIndex !== 'number' || !objectProperty) must be single value input xLine, yLineTo etc
 
         return createCallWrapper(
-          callExp.node.callee.name as any,
+          callExp.callee.name as any,
           rawValues[0].value,
           tag
         )
@@ -1416,7 +1416,7 @@ export function getTransformInfos(
     getNodePathFromSourceRange(ast, range)
   )
   const nodes = paths.map((pathToNode) =>
-    getNodeFromPath<Value>(ast, pathToNode, 'CallExpression')
+    getNodeFromPath<CallExpression>(ast, pathToNode, 'CallExpression')
   )
 
   try {
@@ -1426,9 +1426,8 @@ export function getTransformInfos(
         return false
       }
 
-      const node = nodeMeta.node
-      if (node?.type === 'CallExpression')
-        return getTransformInfo(node, constraintType)
+      const node = nodeMeta.stopAtNode
+      if (node) return getTransformInfo(node, constraintType)
 
       return false
     }) as TransformInfo[]
@@ -1448,9 +1447,7 @@ export function getRemoveConstraintsTransforms(
   const paths = selectionRanges.codeBasedSelections.map((selectionRange) =>
     getNodePathFromSourceRange(ast, selectionRange.range)
   )
-  const nodes = paths.map((pathToNode) =>
-    getNodeFromPath<Value>(ast, pathToNode)
-  )
+  const nodes = paths.map((pathToNode) => getLastNodeFromPath(ast, pathToNode))
 
   const theTransforms = nodes.map((nodeMeta) => {
     // Typescript is not smart enough to know node will never be Error
@@ -1461,7 +1458,11 @@ export function getRemoveConstraintsTransforms(
     }
 
     const node = nodeMeta.node
-    if (node?.type === 'CallExpression')
+    if (isArray(node)) {
+      console.error('Expected node, but found Array')
+      return false
+    }
+    if (isNodeType<CallExpression>(node, 'CallExpression'))
       return getRemoveConstraintsTransform(node, constraintType)
 
     return false
@@ -1579,15 +1580,17 @@ export function transformAstSketchLines({
 
     const callExp = getNode<CallExpression>('CallExpression')
     if (err(callExp)) return callExp
+    if (!callExp.stopAtNode) return new Error('Call expression not found')
     const varDec = getNode<VariableDeclarator>('VariableDeclarator')
     if (err(varDec)) return varDec
+    if (!varDec.stopAtNode) return new Error('Variable declaration not found')
 
-    const firstArg = getFirstArg(callExp.node)
+    const firstArg = getFirstArg(callExp.stopAtNode)
     if (err(firstArg)) return firstArg
-    const callBackTag = callExp.node.arguments[2]
+    const callBackTag = callExp.stopAtNode.arguments[2]
     const _referencedSegmentNameVal =
-      callExp.node.arguments[0]?.type === 'ObjectExpression' &&
-      callExp.node.arguments[0].properties?.find(
+      callExp.stopAtNode.arguments[0]?.type === 'ObjectExpression' &&
+      callExp.stopAtNode.arguments[0].properties?.find(
         (prop) => prop.key.name === 'intersectTag'
       )?.value
     const _referencedSegmentName =
@@ -1601,7 +1604,7 @@ export function transformAstSketchLines({
 
     const varValues: VarValues = []
 
-    getConstraintInfo(callExp.node, '', _pathToNode).forEach((a) => {
+    getConstraintInfo(callExp.stopAtNode, '', _pathToNode).forEach((a) => {
       if (
         a.type === 'tangentialWithPrevious' ||
         a.type === 'horizontal' ||
@@ -1609,33 +1612,46 @@ export function transformAstSketchLines({
       )
         return
 
-      const nodeMeta = getNodeFromPath<Value>(ast, a.pathToNode)
+      const nodeMeta = getLastNodeFromPath(ast, a.pathToNode)
       if (err(nodeMeta)) return
 
+      // TODO: Assert that the node is a valid value.
       if (a?.argPosition?.type === 'arrayItem') {
+        if (isArray(nodeMeta.node)) {
+          console.log('Expected Value, but found Array')
+          return
+        }
         varValues.push({
           type: 'arrayItem',
           index: a.argPosition.index,
-          value: nodeMeta.node,
+          value: nodeMeta.node as Value,
           argType: a.type,
         })
       } else if (a?.argPosition?.type === 'objectProperty') {
+        if (isArray(nodeMeta.node)) {
+          console.log('Expected Value, but found Array')
+          return
+        }
         varValues.push({
           type: 'objectProperty',
           key: a.argPosition.key,
-          value: nodeMeta.node,
+          value: nodeMeta.node as Value,
           argType: a.type,
         })
       } else if (a?.argPosition?.type === 'singleValue') {
+        if (isArray(nodeMeta.node)) {
+          console.log('Expected Value, but found Array')
+          return
+        }
         varValues.push({
           type: 'singleValue',
           argType: a.type,
-          value: nodeMeta.node,
+          value: nodeMeta.node as Value,
         })
       }
     })
 
-    const varName = varDec.node.id.name
+    const varName = varDec.stopAtNode.id.name
     let sketchGroup = programMemory.get(varName)
     if (sketchGroup?.type === 'ExtrudeGroup') {
       sketchGroup = sketchGroup.sketchGroup
@@ -1669,7 +1685,7 @@ export function transformAstSketchLines({
       programMemory,
       pathToNode: _pathToNode,
       referencedSegment,
-      fnName: transformTo || (callExp.node.callee.name as ToolTip),
+      fnName: transformTo || (callExp.stopAtNode.callee.name as ToolTip),
       to,
       from,
       createCallback: callBack({
@@ -1743,15 +1759,14 @@ export function getConstraintLevelFromSourceRange(
   ast: Program | Error
 ): Error | { range: [number, number]; level: ConstraintLevel } {
   if (err(ast)) return ast
-  const nodeMeta = getNodeFromPath<CallExpression>(
+  const sketchFnExp = expectNodeOnPath<CallExpression>(
     ast,
     getNodePathFromSourceRange(ast, cursorRange),
     'CallExpression'
   )
-  if (err(nodeMeta)) return nodeMeta
+  if (err(sketchFnExp)) return sketchFnExp
 
-  const { node: sketchFnExp } = nodeMeta
-  const name = sketchFnExp?.callee?.name as ToolTip
+  const name = sketchFnExp.callee.name as ToolTip
   const range: [number, number] = [sketchFnExp.start, sketchFnExp.end]
   if (!toolTips.includes(name)) return { level: 'free', range: range }
 

src/lib/selections.ts

@@ -5,15 +5,16 @@ import {
   kclManager,
   sceneEntitiesManager,
 } from 'lib/singletons'
-import { CallExpression, SourceRange, Value, parse, recast } from 'lang/wasm'
+import { CallExpression, SourceRange, parse, recast } from 'lang/wasm'
 import { ModelingMachineEvent } from 'machines/modelingMachine'
-import { uuidv4 } from 'lib/utils'
+import { isArray, uuidv4 } from 'lib/utils'
 import { EditorSelection, SelectionRange } from '@codemirror/state'
 import { getNormalisedCoordinates, isOverlap } from 'lib/utils'
 import { isCursorInSketchCommandRange } from 'lang/util'
 import { Program } from 'lang/wasm'
 import {
   doesPipeHaveCallExp,
+  getLastNodeFromPath,
   getNodeFromPath,
   hasSketchPipeBeenExtruded,
   isSingleCursorInPipe,
@@ -177,7 +178,11 @@ export function getEventForSegmentSelection(
   )
   if (err(nodeMeta)) return null
 
-  const node = nodeMeta.node
+  const node = nodeMeta.stopAtNode
+  if (!node) {
+    console.error('Call expression not found')
+    return null
+  }
   const range: SourceRange = [node.start, node.end]
   return {
     type: 'Set selection',
@@ -300,7 +305,11 @@ function updateSceneObjectColors(codeBasedSelections: Selection[]) {
       'CallExpression'
     )
     if (err(nodeMeta)) return
-    const node = nodeMeta.node
+    const node = nodeMeta.stopAtNode
+    if (!node) {
+      console.error('Call expression not found')
+      return
+    }
     const groupHasCursor = codeBasedSelections.some((selection) => {
       return isOverlap(selection.range, [node.start, node.end])
     })
@@ -597,9 +606,10 @@ export function updateSelections(
 
   const newSelections = Object.entries(pathToNodeMap)
     .map(([index, pathToNode]): Selection | undefined => {
-      const nodeMeta = getNodeFromPath<Value>(ast, pathToNode)
+      const nodeMeta = getLastNodeFromPath(ast, pathToNode)
       if (err(nodeMeta)) return undefined
       const node = nodeMeta.node
+      if (isArray(node)) return undefined
       return {
         range: [node.start, node.end],
         type: prevSelectionRanges.codeBasedSelections[Number(index)]?.type,

src/lib/utils.ts

@@ -4,6 +4,13 @@ import { v4 } from 'uuid'
 
 export const uuidv4 = v4
 
+/**
+ * A safer type guard for arrays since the built-in Array.isArray() asserts `any[]`.
+ */
+export function isArray(val: any): val is unknown[] {
+  return Array.isArray(val)
+}
+
 export function isOverlap(a: SourceRange, b: SourceRange) {
   const [startingRange, secondRange] = a[0] < b[0] ? [a, b] : [b, a]
   const [lastOfFirst, firstOfSecond] = [startingRange[1], secondRange[0]]

src/machines/modelingMachine.ts

@@ -11,6 +11,7 @@ import { SidebarType } from 'components/ModelingSidebar/ModelingPanes'
 import {
   isNodeSafeToReplacePath,
   getNodePathFromSourceRange,
+  expectNodeOnPath,
 } from 'lang/queryAst'
 import {
   kclManager,
@@ -879,8 +880,8 @@ export const modelingMachine = createMachine(
           'VariableDeclarator'
         )
         if (err(variableDeclaration)) return false
-        if (variableDeclaration.node.type !== 'VariableDeclarator') return false
-        const pipeExpression = variableDeclaration.node.init
+        if (!variableDeclaration.stopAtNode) return false
+        const pipeExpression = variableDeclaration.stopAtNode.init
         if (pipeExpression.type !== 'PipeExpression') return false
         const hasStartSketchOn = pipeExpression.body.some(
           (item) =>
@@ -1134,13 +1135,13 @@ export const modelingMachine = createMachine(
           selection.codeBasedSelections[0].range
         )
 
-        const varDecNode = getNodeFromPath<VariableDeclaration>(
+        const varDecNode = expectNodeOnPath<VariableDeclaration>(
           ast,
           pathToSegmentNode,
           'VariableDeclaration'
         )
         if (err(varDecNode)) return
-        const sketchVar = varDecNode.node.declarations[0].id.name
+        const sketchVar = varDecNode.declarations[0].id.name
         const sketchGroup = kclManager.programMemory.get(sketchVar)
         if (sketchGroup?.type !== 'SketchGroup') return
         const idArtifact = engineCommandManager.artifactMap[sketchGroup.id]
@@ -1625,14 +1626,13 @@ export function isEditingExistingSketch({
   // should check that the variable declaration is a pipeExpression
   // and that the pipeExpression contains a "startProfileAt" callExpression
   if (!sketchDetails?.sketchPathToNode) return false
-  const variableDeclaration = getNodeFromPath<VariableDeclarator>(
+  const variableDeclaration = expectNodeOnPath<VariableDeclarator>(
     kclManager.ast,
     sketchDetails.sketchPathToNode,
     'VariableDeclarator'
   )
   if (err(variableDeclaration)) return false
-  if (variableDeclaration.node.type !== 'VariableDeclarator') return false
-  const pipeExpression = variableDeclaration.node.init
+  const pipeExpression = variableDeclaration.init
   if (pipeExpression.type !== 'PipeExpression') return false
   const hasStartProfileAt = pipeExpression.body.some(
     (item) =>
@@ -1654,5 +1654,5 @@ export function canRectangleTool({
   // This should not be returning false, and it should be caught
   // but we need to simulate old behavior to move on.
   if (err(node)) return false
-  return node.node?.declarations?.[0]?.init.type !== 'PipeExpression'
+  return node.stopAtNode?.declarations?.[0]?.init.type !== 'PipeExpression'
 }

src/wasm-lib/kcl-macros/tests/macro_test.rs

@@ -37,6 +37,7 @@ fn basic() {
             digest: None,
         })],
         non_code_meta: NonCodeMeta::default(),
+        ts_type: (),
         digest: None,
     };
     assert_eq!(expected, actual);

src/wasm-lib/kcl/src/ast/types.rs

@@ -41,6 +41,17 @@ pub type Digest = [u8; 32];
 #[ts(export)]
 #[serde(rename_all = "camelCase")]
 pub struct Program {
+    // This is so that it can be used with other AST nodes in TypeScript and the
+    // node type can be determined at runtime.
+    #[serde(
+        default,
+        rename = "type",
+        serialize_with = "Program::serialize_ts_type",
+        skip_deserializing
+    )]
+    #[ts(rename = "type", type = "\"Program\"")]
+    pub ts_type: (),
+
     pub start: usize,
     pub end: usize,
     pub body: Vec<BodyItem>,
@@ -82,6 +93,13 @@ impl Program {
         hasher.update(slf.non_code_meta.compute_digest());
     });
 
+    fn serialize_ts_type<S>(_: &(), serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: serde::Serializer,
+    {
+        serializer.serialize_str("Program")
+    }
+
     pub fn get_hover_value_for_position(&self, pos: usize, code: &str) -> Option<Hover> {
         // Check if we are in the non code meta.
         if let Some(meta) = self.get_non_code_meta_for_position(pos) {
@@ -5695,6 +5713,7 @@ const thickness = sqrt(distance * p * FOS * 6 / (sigmaAllow * width))"#;
                         end: 0,
                         body: Vec::new(),
                         non_code_meta: Default::default(),
+                        ts_type: (),
                         digest: None,
                     },
                     return_type: None,
@@ -5723,6 +5742,7 @@ const thickness = sqrt(distance * p * FOS * 6 / (sigmaAllow * width))"#;
                         end: 0,
                         body: Vec::new(),
                         non_code_meta: Default::default(),
+                        ts_type: (),
                         digest: None,
                     },
                     return_type: None,
@@ -5751,6 +5771,7 @@ const thickness = sqrt(distance * p * FOS * 6 / (sigmaAllow * width))"#;
                         end: 0,
                         body: Vec::new(),
                         non_code_meta: Default::default(),
+                        ts_type: (),
                         digest: None,
                     },
                     return_type: None,
@@ -5792,6 +5813,7 @@ const thickness = sqrt(distance * p * FOS * 6 / (sigmaAllow * width))"#;
                         end: 0,
                         body: Vec::new(),
                         non_code_meta: Default::default(),
+                        ts_type: (),
                         digest: None,
                     },
                     return_type: None,

src/wasm-lib/kcl/src/executor.rs

@@ -2910,6 +2910,7 @@ let w = f() + f()
                     end: 0,
                     body: Vec::new(),
                     non_code_meta: Default::default(),
+                    ts_type: (),
                     digest: None,
                 },
                 return_type: None,

src/wasm-lib/kcl/src/parser/parser_impl.rs

@@ -872,6 +872,7 @@ pub fn function_body(i: TokenSlice) -> PResult<Program> {
         end,
         body,
         non_code_meta,
+        ts_type: (),
         digest: None,
     })
 }
@@ -1746,6 +1747,7 @@ const mySk1 = startSketchAt([0, 0])"#;
                         }],
                         digest: None,
                     },
+                    ts_type: (),
                     digest: None,
                 },
                 return_type: None,
@@ -2400,6 +2402,7 @@ const mySk1 = startSketchAt([0, 0])"#;
                 digest: None,
             })],
             non_code_meta: NonCodeMeta::default(),
+            ts_type: (),
             digest: None,
         };
 
@@ -2864,6 +2867,7 @@ e
                 digest: None,
             })],
             non_code_meta: NonCodeMeta::default(),
+            ts_type: (),
             digest: None,
         };