Fix a recast bug and don't delete the user's code if parsing fails (#5663)

Signed-off-by: Nick Cameron <nrc@ncameron.org>

rust/kcl-lib/src/unparser.rs

@@ -450,7 +450,7 @@ impl Literal {
                 if self.raw.contains('.') && value.fract() == 0.0 {
                     format!("{value:?}{suffix}")
                 } else {
-                    format!("{}{suffix}", self.raw)
+                    self.raw.clone()
                 }
             }
             LiteralValue::String(ref s) => {
@@ -1540,7 +1540,7 @@ tabs_l = startSketchOn({
        radius = hole_diam / 2
      ), %)
   |> extrude(-thk, %)
-  |> patternLinear3d(axis = [0, -1, 0], repetitions = 1, distance = length - 10)
+  |> patternLinear3d(axis = [0, -1, 0], repetitions = 1, distance = length - 10ft)
 "#;
         let program = crate::parsing::top_level_parse(some_program_string).unwrap();
 
@@ -1657,7 +1657,7 @@ tabs_l = startSketchOn({
        radius = hole_diam / 2,
      ), %)
   |> extrude(-thk, %)
-  |> patternLinear3d(axis = [0, -1, 0], repetitions = 1, distance = length - 10)
+  |> patternLinear3d(axis = [0, -1, 0], repetitions = 1, distance = length - 10ft)
 "#
         );
     }

src/lang/KclSingleton.ts

@@ -452,7 +452,7 @@ export class KclManager {
 
   // NOTE: this always updates the code state and editor.
   // DO NOT CALL THIS from codemirror ever.
-  async executeAstMock(ast: Program = this._ast) {
+  async executeAstMock(ast: Program) {
     await this.ensureWasmInit()
 
     const newCode = recast(ast)
@@ -462,6 +462,8 @@ export class KclManager {
     }
     const newAst = await this.safeParse(newCode)
     if (!newAst) {
+      // By clearning the AST we indicate to our callers that there was an issue with execution and
+      // the pre-execution state should be restored.
       this.clearAst()
       return
     }
@@ -474,10 +476,6 @@ export class KclManager {
     })
 
     this._logs = logs
-    this.addDiagnostics(kclErrorsToDiagnostics(errors))
-    // Add warnings and non-fatal errors
-    this.addDiagnostics(complilationErrorsToDiagnostics(execState.errors))
-
     this._execState = execState
     this._variables = execState.variables
     if (!errors.length) {
@@ -494,6 +492,8 @@ export class KclManager {
     const ast = await this.safeParse(codeManager.code)
 
     if (!ast) {
+      // By clearning the AST we indicate to our callers that there was an issue with execution and
+      // the pre-execution state should be restored.
       this.clearAst()
       return
     }

src/lang/codeManager.ts

@@ -7,7 +7,7 @@ import toast from 'react-hot-toast'
 import { editorManager } from 'lib/singletons'
 import { Annotation, Transaction } from '@codemirror/state'
 import { EditorView, KeyBinding } from '@codemirror/view'
-import { recast, Program } from 'lang/wasm'
+import { recast, Program, parse } from 'lang/wasm'
 import { err, reportRejection } from 'lib/trap'
 import { Compartment } from '@codemirror/state'
 import { history } from '@codemirror/commands'
@@ -165,8 +165,20 @@ export default class CodeManager {
   }
 
   async updateEditorWithAstAndWriteToFile(ast: Program) {
+    // We clear the AST when there it cannot be parsed, so if we are trying to write an empty AST, its
+    // probably because of an earlier error. That's a bad state to be in and it's not going to be
+    // pretty, but at the least, lets not permanently delete the user's code.
+    // If you want to clear the scene, call updateCodeStateEditor directly.
+    if (ast.body.length === 0) return
     const newCode = recast(ast)
     if (err(newCode)) return
+    // Test to see if we can parse the recast code, and never update the editor with bad code.
+    // This should never happen ideally and should mean there is a bug in recast.
+    const result = parse(newCode)
+    if (err(result)) {
+      console.log('Recast code could not be parsed:', result, ast)
+      return
+    }
     this.updateCodeStateEditor(newCode)
     this.writeToFile().catch(reportRejection)
   }