Look at this (photo)Graph *in the voice of Nickelback*

src/hooks/useEngineConnectionSubscriptions.ts

@@ -9,6 +9,7 @@ import { useModelingContext } from './useModelingContext'
 import { getEventForSelectWithPoint } from 'lib/selections'
 import {
   getCapCodeRef,
+  getExtrudeEdgeCodeRef,
   getExtrusionFromSuspectedExtrudeSurface,
   getSolid2dCodeRef,
   getWallCodeRef,
@@ -60,6 +61,13 @@ export function useEngineConnectionSubscriptions() {
                 ? [codeRef.range]
                 : [codeRef.range, extrusion.codeRef.range]
             )
+          } else if (artifact?.type === 'extrudeEdge') {
+            const codeRef = getExtrudeEdgeCodeRef(
+              artifact,
+              engineCommandManager.artifactGraph
+            )
+            if (err(codeRef)) return
+            editorManager.setHighlightRange([codeRef.range])
           } else if (artifact?.type === 'segment') {
             editorManager.setHighlightRange([
               artifact?.codeRef?.range || [0, 0],

src/lang/modifyAst/addFillet.ts

@@ -35,6 +35,7 @@ export function addFillet(
   node: Program,
   pathToSegmentNode: PathToNode,
   pathToExtrudeNode: PathToNode,
+  edgeType: 'oppositeEdge' | 'adjacentEdge' | 'default',
   radius = createLiteral(5) as Value
   // shouldPipe = false, // TODO: Implement this feature
 ): { modifiedAst: Program; pathToFilletNode: PathToNode } | Error {
@@ -84,10 +85,18 @@ export function addFillet(
    */
 
   // Create the fillet call expression in one line
+
+  let tagCall: Value = createIdentifier(tag)
+  if (edgeType === 'oppositeEdge') {
+    tagCall = createCallExpressionStdLib('getOppositeEdge', [tagCall])
+  } else if (edgeType === 'adjacentEdge') {
+    tagCall = createCallExpressionStdLib('getNextAdjacentEdge', [tagCall])
+  }
+
   const filletCall = createCallExpressionStdLib('fillet', [
     createObjectExpression({
       radius: radius,
-      tags: createArrayExpression([createIdentifier(tag)]),
+      tags: createArrayExpression([tagCall]),
     }),
     createPipeSubstitution(),
   ])
@@ -178,11 +187,13 @@ export function addFillet(
     extrudeDeclarator.init = createPipeExpression([extrudeInit, filletCall])
     return {
       modifiedAst: _node,
-      pathToFilletNode: getPathToNodeOfFilletLiteral(
+      pathToFilletNode: [],
-        pathToExtrudeNode,
+      // TODO fix and re-enable this
-        extrudeDeclarator,
+      // pathToFilletNode: getPathToNodeOfFilletLiteral(
-        tag
+      //   pathToExtrudeNode,
-      ),
+      //   extrudeDeclarator,
+      //   tag
+      // ),
     }
   } else if (extrudeInit.type === 'PipeExpression') {
     // 2. fillet case

src/lang/std/__snapshots__/artifactGraph.test.ts.snap

@@ -58,7 +58,10 @@ Map {
         92,
       ],
     },
-    "edgeIds": [],
+    "edgeIds": [
+      "UUID",
+      "UUID",
+    ],
     "pathId": "UUID",
     "surfaceId": "UUID",
     "type": "segment",
@@ -77,7 +80,10 @@ Map {
       ],
     },
     "edgeCutId": "UUID",
-    "edgeIds": [],
+    "edgeIds": [
+      "UUID",
+      "UUID",
+    ],
     "pathId": "UUID",
     "surfaceId": "UUID",
     "type": "segment",
@@ -95,7 +101,10 @@ Map {
         156,
       ],
     },
-    "edgeIds": [],
+    "edgeIds": [
+      "UUID",
+      "UUID",
+    ],
     "pathId": "UUID",
     "surfaceId": "UUID",
     "type": "segment",
@@ -113,7 +122,10 @@ Map {
         209,
       ],
     },
-    "edgeIds": [],
+    "edgeIds": [
+      "UUID",
+      "UUID",
+    ],
     "pathId": "UUID",
     "surfaceId": "UUID",
     "type": "segment",
@@ -152,7 +164,16 @@ Map {
         266,
       ],
     },
-    "edgeIds": [],
+    "edgeIds": [
+      "UUID",
+      "UUID",
+      "UUID",
+      "UUID",
+      "UUID",
+      "UUID",
+      "UUID",
+      "UUID",
+    ],
     "pathId": "UUID",
     "surfaceIds": [
       "UUID",
@@ -209,6 +230,54 @@ Map {
     "type": "cap",
   },
   "UUID-15" => {
+    "extrusionId": "UUID",
+    "segId": "UUID",
+    "subType": "opposite",
+    "type": "extrudeEdge",
+  },
+  "UUID-16" => {
+    "extrusionId": "UUID",
+    "segId": "UUID",
+    "subType": "adjacent",
+    "type": "extrudeEdge",
+  },
+  "UUID-17" => {
+    "extrusionId": "UUID",
+    "segId": "UUID",
+    "subType": "opposite",
+    "type": "extrudeEdge",
+  },
+  "UUID-18" => {
+    "extrusionId": "UUID",
+    "segId": "UUID",
+    "subType": "adjacent",
+    "type": "extrudeEdge",
+  },
+  "UUID-19" => {
+    "extrusionId": "UUID",
+    "segId": "UUID",
+    "subType": "opposite",
+    "type": "extrudeEdge",
+  },
+  "UUID-20" => {
+    "extrusionId": "UUID",
+    "segId": "UUID",
+    "subType": "adjacent",
+    "type": "extrudeEdge",
+  },
+  "UUID-21" => {
+    "extrusionId": "UUID",
+    "segId": "UUID",
+    "subType": "opposite",
+    "type": "extrudeEdge",
+  },
+  "UUID-22" => {
+    "extrusionId": "UUID",
+    "segId": "UUID",
+    "subType": "adjacent",
+    "type": "extrudeEdge",
+  },
+  "UUID-23" => {
     "codeRef": {
       "pathToNode": [
         [
@@ -226,7 +295,7 @@ Map {
     "subType": "fillet",
     "type": "edgeCut",
   },
-  "UUID-16" => {
+  "UUID-24" => {
     "codeRef": {
       "pathToNode": [
         [
@@ -250,7 +319,7 @@ Map {
     "solid2dId": "UUID",
     "type": "path",
   },
-  "UUID-17" => {
+  "UUID-25" => {
     "codeRef": {
       "pathToNode": [
         [
@@ -263,12 +332,15 @@ Map {
         416,
       ],
     },
-    "edgeIds": [],
+    "edgeIds": [
+      "UUID",
+      "UUID",
+    ],
     "pathId": "UUID",
     "surfaceId": "UUID",
     "type": "segment",
   },
-  "UUID-18" => {
+  "UUID-26" => {
     "codeRef": {
       "pathToNode": [
         [
@@ -281,12 +353,15 @@ Map {
         438,
       ],
     },
-    "edgeIds": [],
+    "edgeIds": [
+      "UUID",
+      "UUID",
+    ],
     "pathId": "UUID",
     "surfaceId": "UUID",
     "type": "segment",
   },
-  "UUID-19" => {
+  "UUID-27" => {
     "codeRef": {
       "pathToNode": [
         [
@@ -299,12 +374,15 @@ Map {
         491,
       ],
     },
-    "edgeIds": [],
+    "edgeIds": [
+      "UUID",
+      "UUID",
+    ],
     "pathId": "UUID",
     "surfaceId": "UUID",
     "type": "segment",
   },
-  "UUID-20" => {
+  "UUID-28" => {
     "codeRef": {
       "pathToNode": [
         [
@@ -321,11 +399,11 @@ Map {
     "pathId": "UUID",
     "type": "segment",
   },
-  "UUID-21" => {
+  "UUID-29" => {
     "pathId": "UUID",
     "type": "solid2D",
   },
-  "UUID-22" => {
+  "UUID-30" => {
     "codeRef": {
       "pathToNode": [
         [
@@ -338,7 +416,14 @@ Map {
         546,
       ],
     },
-    "edgeIds": [],
+    "edgeIds": [
+      "UUID",
+      "UUID",
+      "UUID",
+      "UUID",
+      "UUID",
+      "UUID",
+    ],
     "pathId": "UUID",
     "surfaceIds": [
       "UUID",
@@ -349,40 +434,76 @@ Map {
     ],
     "type": "extrusion",
   },
-  "UUID-23" => {
+  "UUID-31" => {
     "edgeCutEdgeIds": [],
     "extrusionId": "UUID",
     "pathIds": [],
     "segId": "UUID",
     "type": "wall",
   },
-  "UUID-24" => {
+  "UUID-32" => {
     "edgeCutEdgeIds": [],
     "extrusionId": "UUID",
     "pathIds": [],
     "segId": "UUID",
     "type": "wall",
   },
-  "UUID-25" => {
+  "UUID-33" => {
     "edgeCutEdgeIds": [],
     "extrusionId": "UUID",
     "pathIds": [],
     "segId": "UUID",
     "type": "wall",
   },
-  "UUID-26" => {
+  "UUID-34" => {
     "edgeCutEdgeIds": [],
     "extrusionId": "UUID",
     "pathIds": [],
     "subType": "start",
     "type": "cap",
   },
-  "UUID-27" => {
+  "UUID-35" => {
     "edgeCutEdgeIds": [],
     "extrusionId": "UUID",
     "pathIds": [],
     "subType": "end",
     "type": "cap",
   },
+  "UUID-36" => {
+    "extrusionId": "UUID",
+    "segId": "UUID",
+    "subType": "opposite",
+    "type": "extrudeEdge",
+  },
+  "UUID-37" => {
+    "extrusionId": "UUID",
+    "segId": "UUID",
+    "subType": "adjacent",
+    "type": "extrudeEdge",
+  },
+  "UUID-38" => {
+    "extrusionId": "UUID",
+    "segId": "UUID",
+    "subType": "opposite",
+    "type": "extrudeEdge",
+  },
+  "UUID-39" => {
+    "extrusionId": "UUID",
+    "segId": "UUID",
+    "subType": "adjacent",
+    "type": "extrudeEdge",
+  },
+  "UUID-40" => {
+    "extrusionId": "UUID",
+    "segId": "UUID",
+    "subType": "opposite",
+    "type": "extrudeEdge",
+  },
+  "UUID-41" => {
+    "extrusionId": "UUID",
+    "segId": "UUID",
+    "subType": "adjacent",
+    "type": "extrudeEdge",
+  },
 }
 `;

src/lang/std/artifactGraph.test.ts

@@ -251,7 +251,7 @@ describe('testing createArtifactGraph', () => {
       // of the edges refers to a non-existent node, the graph will throw.
       // further more we can check that each edge is bi-directional, if it's not
       // by checking the arrow heads going both ways, on the graph.
-      await GraphTheGraph(theMap, 1400, 1400, 'exampleCode1.png')
+      await GraphTheGraph(theMap, 2000, 2000, 'exampleCode1.png')
     }, 20000)
   })
 })
@@ -275,7 +275,7 @@ describe('capture graph of sketchOnFaceOnFace...', () => {
       // of the edges refers to a non-existent node, the graph will throw.
       // further more we can check that each edge is bi-directional, if it's not
       // by checking the arrow heads going both ways, on the graph.
-      await GraphTheGraph(theMap, 2500, 2500, 'sketchOnFaceOnFaceEtc.png')
+      await GraphTheGraph(theMap, 3000, 3000, 'sketchOnFaceOnFaceEtc.png')
     }, 20000)
   })
 })
@@ -607,7 +607,7 @@ describe('testing getArtifactsToUpdate', () => {
         type: 'segment',
         pathId: expect.any(String),
         surfaceId: expect.any(String),
-        edgeIds: [],
+        edgeIds: expect.any(Array),
         codeRef: {
           range: [98, 125],
           pathToNode: [['body', '']],
@@ -627,7 +627,7 @@ describe('testing getArtifactsToUpdate', () => {
         type: 'segment',
         pathId: expect.any(String),
         surfaceId: expect.any(String),
-        edgeIds: [],
+        edgeIds: expect.any(Array),
         codeRef: {
           range: [162, 209],
           pathToNode: [['body', '']],
@@ -637,7 +637,7 @@ describe('testing getArtifactsToUpdate', () => {
         type: 'extrusion',
         pathId: expect.any(String),
         surfaceIds: expect.any(Array),
-        edgeIds: [],
+        edgeIds: expect.any(Array),
         codeRef: {
           range: [243, 266],
           pathToNode: [['body', '']],
@@ -654,7 +654,7 @@ describe('testing getArtifactsToUpdate', () => {
         type: 'segment',
         pathId: expect.any(String),
         surfaceId: expect.any(String),
-        edgeIds: [],
+        edgeIds: expect.any(Array),
         codeRef: {
           range: [131, 156],
           pathToNode: [['body', '']],
@@ -664,7 +664,7 @@ describe('testing getArtifactsToUpdate', () => {
         type: 'extrusion',
         pathId: expect.any(String),
         surfaceIds: expect.any(Array),
-        edgeIds: [],
+        edgeIds: expect.any(Array),
         codeRef: {
           range: [243, 266],
           pathToNode: [['body', '']],
@@ -681,7 +681,7 @@ describe('testing getArtifactsToUpdate', () => {
         type: 'segment',
         pathId: expect.any(String),
         surfaceId: expect.any(String),
-        edgeIds: [],
+        edgeIds: expect.any(Array),
         codeRef: {
           range: [98, 125],
           pathToNode: [['body', '']],
@@ -692,7 +692,7 @@ describe('testing getArtifactsToUpdate', () => {
         type: 'extrusion',
         pathId: expect.any(String),
         surfaceIds: expect.any(Array),
-        edgeIds: [],
+        edgeIds: expect.any(Array),
         codeRef: {
           range: [243, 266],
           pathToNode: [['body', '']],
@@ -709,7 +709,7 @@ describe('testing getArtifactsToUpdate', () => {
         type: 'segment',
         pathId: expect.any(String),
         surfaceId: expect.any(String),
-        edgeIds: [],
+        edgeIds: expect.any(Array),
         codeRef: {
           range: [76, 92],
           pathToNode: [['body', '']],
@@ -719,7 +719,7 @@ describe('testing getArtifactsToUpdate', () => {
         type: 'extrusion',
         pathId: expect.any(String),
         surfaceIds: expect.any(Array),
-        edgeIds: [],
+        edgeIds: expect.any(Array),
         codeRef: {
           range: [243, 266],
           pathToNode: [['body', '']],
@@ -736,7 +736,7 @@ describe('testing getArtifactsToUpdate', () => {
         type: 'extrusion',
         pathId: expect.any(String),
         surfaceIds: expect.any(Array),
-        edgeIds: [],
+        edgeIds: expect.any(Array),
         codeRef: {
           range: [243, 266],
           pathToNode: [['body', '']],
@@ -753,7 +753,7 @@ describe('testing getArtifactsToUpdate', () => {
         type: 'extrusion',
         pathId: expect.any(String),
         surfaceIds: expect.any(Array),
-        edgeIds: [],
+        edgeIds: expect.any(Array),
         codeRef: {
           range: [243, 266],
           pathToNode: [['body', '']],

src/lang/std/artifactGraph.ts

@@ -86,12 +86,11 @@ interface CapArtifact {
   extrusionId: string
   pathIds: Array<string>
 }
-
+export interface ExtrudeEdge {
-interface ExtrudeEdge {
   type: 'extrudeEdge'
   segId: string
   extrusionId: string
-  edgeId: string
+  subType: 'opposite' | 'adjacent'
 }
 
 /** A edgeCut is a more generic term for both fillet or chamfer */
@@ -422,6 +421,54 @@ export function getArtifactsToUpdate({
       }
     })
     return returnArr
+  } else if (
+    (cmd.type === 'solid3d_get_opposite_edge' &&
+      response.type === 'modeling' &&
+      response.data.modeling_response.type === 'solid3d_get_opposite_edge' &&
+      response.data.modeling_response.data.edge) ||
+    (cmd.type === 'solid3d_get_prev_adjacent_edge' &&
+      response.type === 'modeling' &&
+      response.data.modeling_response.type ===
+        'solid3d_get_prev_adjacent_edge' &&
+      response.data.modeling_response.data.edge)
+  ) {
+    const wall = getArtifact(cmd.face_id)
+    if (wall?.type !== 'wall') return returnArr
+    const extrusion = getArtifact(wall.extrusionId)
+    if (extrusion?.type !== 'extrusion') return returnArr
+    const path = getArtifact(extrusion.pathId)
+    if (path?.type !== 'path') return returnArr
+    const segment = getArtifact(cmd.edge_id)
+    if (segment?.type !== 'segment') return returnArr
+
+    return [
+      {
+        id: response.data.modeling_response.data.edge,
+        artifact: {
+          type: 'extrudeEdge',
+          subType:
+            cmd.type === 'solid3d_get_prev_adjacent_edge'
+              ? 'adjacent'
+              : 'opposite',
+          segId: cmd.edge_id,
+          extrusionId: path.extrusionId,
+        },
+      },
+      {
+        id: cmd.edge_id,
+        artifact: {
+          ...segment,
+          edgeIds: [response.data.modeling_response.data.edge],
+        },
+      },
+      {
+        id: path.extrusionId,
+        artifact: {
+          ...extrusion,
+          edgeIds: [response.data.modeling_response.data.edge],
+        },
+      },
+    ]
   } else if (cmd.type === 'solid3d_fillet_edge') {
     returnArr.push({
       id,
@@ -655,6 +702,18 @@ export function getWallCodeRef(
   return seg.codeRef
 }
 
+export function getExtrudeEdgeCodeRef(
+  edge: ExtrudeEdge,
+  artifactGraph: ArtifactGraph
+): CommonCommandProperties | Error {
+  const seg = getArtifactOfTypes(
+    { key: edge.segId, types: ['segment'] },
+    artifactGraph
+  )
+  if (err(seg)) return seg
+  return seg.codeRef
+}
+
 export function getExtrusionFromSuspectedExtrudeSurface(
   id: string,
   artifactGraph: ArtifactGraph

src/lib/selections.ts

@@ -30,9 +30,11 @@ import { AXIS_GROUP, X_AXIS } from 'clientSideScene/sceneInfra'
 import { PathToNodeMap } from 'lang/std/sketchcombos'
 import { err } from 'lib/trap'
 import {
+  ExtrudeEdge,
   getArtifactOfTypes,
   getArtifactsOfTypes,
   getCapCodeRef,
+  getExtrudeEdgeCodeRef,
   getSolid2dCodeRef,
   getWallCodeRef,
 } from 'lang/std/artifactGraph'
@@ -56,6 +58,8 @@ export type Selection = {
     | 'line'
     | 'arc'
     | 'all'
+    | 'opposite-edge'
+    | 'adjacent-edge'
   range: SourceRange
 }
 export type Selections = {
@@ -85,6 +89,7 @@ export async function getEventForSelectWithPoint({
     }
   }
   let _artifact = engineCommandManager.artifactGraph.get(data.entity_id)
+  console.log('entity id', data.entity_id)
   if (!_artifact)
     return {
       type: 'Set selection',
@@ -141,6 +146,27 @@ export async function getEventForSelectWithPoint({
       },
     }
   }
+  if (_artifact.type === 'extrudeEdge') {
+    const codeRef = getExtrudeEdgeCodeRef(
+      _artifact,
+      engineCommandManager.artifactGraph
+    )
+    console.log('codeRef', codeRef)
+    if (err(codeRef)) return null
+    return {
+      type: 'Set selection',
+      data: {
+        selectionType: 'singleCodeCursor',
+        selection: {
+          range: codeRef.range,
+          type:
+            _artifact.subType === 'adjacent'
+              ? 'adjacent-edge'
+              : 'opposite-edge',
+        },
+      },
+    }
+  }
   return null
 }
 
@@ -531,6 +557,25 @@ function codeToIdSelections(
           bestCandidate = entry
           return
         }
+        if (
+          (type === 'opposite-edge' || type === 'adjacent-edge') &&
+          entry.artifact.type === 'segment'
+        ) {
+          const tweakedType: ExtrudeEdge['subType'] =
+            type === 'opposite-edge' ? 'opposite' : 'adjacent'
+          const edgeArtifact = [
+            ...getArtifactsOfTypes(
+              { keys: entry.artifact.edgeIds, types: ['extrudeEdge'] },
+              engineCommandManager.artifactGraph
+            ),
+          ].find(([_, edge]) => edge.subType === tweakedType)
+          if (!edgeArtifact) return
+          bestCandidate = {
+            artifact: edgeArtifact[1],
+            selection: { type, range, ...rest },
+            id: edgeArtifact[0],
+          }
+        }
         if (type === 'solid2D' && entry.artifact.type === 'path') {
           const solid = engineCommandManager.artifactGraph.get(
             entry.artifact.solid2dId || ''

src/lib/singletons.ts

@@ -51,4 +51,39 @@ if (typeof window !== 'undefined') {
         padding: 0.2, // padding around the objects
       },
     })
+  ;(window as any).getEdgesForAndAskEngineForType = async (faceId: string) => {
+    // Kurt - Debugging tool used help to show edges aren't stable after further 3d operations
+    // if this was added more than a few months ago, it probably can be removed.
+    const face = engineCommandManager.artifactGraph.get(faceId)
+    if (face?.type !== 'wall') {
+      console.log('was expecting a wall, you gave me a ', face?.type)
+      return
+    }
+    const extrusion = engineCommandManager.artifactGraph.get(face.extrusionId)
+    if (extrusion?.type !== 'extrusion') {
+      console.log('was expecting an extrusion, but got ', extrusion?.type)
+      return
+    }
+    extrusion.edgeIds.forEach(async (edgeId) => {
+      const result = await engineCommandManager
+        .sendSceneCommand({
+          type: 'modeling_cmd_req',
+          cmd_id: uuidv4(),
+          cmd: {
+            type: 'get_entity_type',
+            entity_id: edgeId,
+          },
+        })
+        .catch((a) => console.log('error:', a))
+      if (!result?.success) return
+      if (result.resp.type !== 'modeling') return
+      if (result.resp.data.modeling_response.type !== 'get_entity_type') return
+      console.log(
+        'result edge is: ',
+        result.resp.data.modeling_response.data.entity_type,
+        ' id: ',
+        edgeId
+      )
+    })
+  }
 }

src/machines/modelingMachine.ts

@@ -1197,6 +1197,11 @@ export const modelingMachine = createMachine(
           ast,
           pathToSegmentNode,
           pathToExtrudeNode,
+          selection.codeBasedSelections[0].type === 'opposite-edge'
+            ? 'oppositeEdge'
+            : selection.codeBasedSelections[0].type === 'adjacent-edge'
+            ? 'adjacentEdge'
+            : 'default',
           'variableName' in radius
             ? radius.variableIdentifierAst
             : radius.valueAst
@@ -1206,7 +1211,8 @@ export const modelingMachine = createMachine(
         const { modifiedAst, pathToFilletNode } = addFilletResult
 
         const updatedAst = await kclManager.updateAst(modifiedAst, true, {
-          focusPath: pathToFilletNode,
+          // TODO fix and re-enable
+          // focusPath: pathToFilletNode,
         })
         if (updatedAst?.selections) {
           editorManager.selectRange(updatedAst?.selections)

src/wasm-lib/kcl/src/std/extrude.rs

@@ -181,6 +181,48 @@ pub(crate) async fn do_post_extrude(
         vec![]
     };
 
+    for face_info in face_infos.iter() {
+        if face_info.cap == kittycad::types::ExtrusionFaceCapType::None
+            && face_info.face_id.is_some()
+            && face_info.curve_id.is_some()
+        {
+            match args
+                .batch_modeling_cmd(
+                    uuid::Uuid::new_v4(),
+                    kittycad::types::ModelingCmd::Solid3DGetOppositeEdge {
+                        edge_id: face_info.curve_id.unwrap(),
+                        object_id: sketch_group.id,
+                        face_id: face_info.face_id.unwrap_or_default(),
+                    },
+                )
+                .await
+            {
+                Ok(info) => info,
+                Err(e) => {
+                    eprintln!("Error fetching opposite edge: {:?}", e);
+                    continue;
+                }
+            };
+            match args
+                .batch_modeling_cmd(
+                    uuid::Uuid::new_v4(),
+                    kittycad::types::ModelingCmd::Solid3DGetPrevAdjacentEdge {
+                        edge_id: face_info.curve_id.unwrap(),
+                        object_id: sketch_group.id,
+                        face_id: face_info.face_id.unwrap(),
+                    },
+                )
+                .await
+            {
+                Ok(info) => info,
+                Err(e) => {
+                    eprintln!("Error fetching adjacent edge: {:?}", e);
+                    continue;
+                }
+            };
+        }
+    }
+
     // Create a hashmap for quick id lookup
     let mut face_id_map = std::collections::HashMap::new();
     // creating fake ids for start and end caps is to make extrudes mock-execute safe