Do not crash on empty main function body. (#10990)

Fixes #10976

https://github.com/user-attachments/assets/00b2279d-2acf-468b-8c3c-aa6885cba23d


Addressed issue of empty body block being incorrectly "repaired" into an empty group, geneating invalid `()` syntax. Appending nodes to an empty function now actually replaces its body block, instead of creating a temporary orphan body block node.

Note that empty main function is still considered an error on the engine side, but it doesn't impact the IDE in negative way. Things work again as soon as a node is inserted.

Also fixed a few issues causing hot-reloading to break. Now edited AST code properly hot-reloads all affected modules without breaking the app.

app/gui2/src/components/GraphEditor/GraphNode.vue

@@ -417,7 +417,7 @@ watchEffect(() => {
     @pointerleave="(nodeHovered = false), updateNodeHover(undefined)"
     @pointermove="updateNodeHover"
   >
-    <Teleport v-if="navigator && !edited" :to="graphNodeSelections">
+    <Teleport v-if="navigator && !edited && graphNodeSelections" :to="graphNodeSelections">
       <GraphNodeSelection
         :data-node-id="nodeId"
         :nodePosition="props.node.position"

app/gui2/src/composables/navigator.ts

@@ -164,20 +164,20 @@ export function useNavigator(
   function panToImpl(points: Partial<Vec2>[]) {
     let target = viewport.value
     for (const point of points.reverse()) target = target.offsetToInclude(point) ?? target
-    targetCenter.value = target.center()
+    targetCenter.value = target.center().finiteOrZero()
   }
 
   /** Pan immediately to center the viewport at the given point, in scene coordinates. */
   function scrollTo(newCenter: Vec2) {
     resetTargetFollowing()
-    targetCenter.value = newCenter
+    targetCenter.value = newCenter.finiteOrZero()
     center.skip()
   }
 
   /** Set viewport center point and scale value immediately, skipping animations. */
   function setCenterAndScale(newCenter: Vec2, newScale: number) {
     resetTargetFollowing()
-    targetCenter.value = newCenter
+    targetCenter.value = newCenter.finiteOrZero()
     targetScale.value = newScale
     scale.skip()
     center.skip()
@@ -325,7 +325,7 @@ export function useNavigator(
     const scenePos0 = clientToScenePos(clientPos)
     const result = f()
     const scenePos1 = clientToScenePos(clientPos)
-    targetCenter.value = center.value.add(scenePos0.sub(scenePos1))
+    targetCenter.value = center.value.add(scenePos0.sub(scenePos1)).finiteOrZero()
     center.skip()
     return result
   }

app/gui2/src/providers/index.ts

@@ -31,7 +31,7 @@ const MISSING = Symbol('MISSING')
  * [Context API]: https://vuejs.org/guide/components/provide-inject.html#provide-inject
  */
 export function createContextStore<F extends (...args: any[]) => any>(name: string, factory: F) {
-  const provideKey = Symbol(name) as InjectionKey<ReturnType<F>>
+  const provideKey = Symbol.for(`contextStore-${name}`) as InjectionKey<ReturnType<F>>
 
   /**
    * Create the instance of a store and store it in the current component's context. All child

app/gui2/src/stores/graph/graphDatabase.ts

@@ -44,7 +44,7 @@ export class BindingsDb {
 
   readFunctionAst(
     func: Ast.Function,
-    rawFunc: RawAst.Tree.Function,
+    rawFunc: RawAst.Tree.Function | undefined,
     moduleCode: string,
     getSpan: (id: AstId) => SourceRange | undefined,
   ) {
@@ -422,7 +422,7 @@ export class GraphDb {
   /** Deeply scan the function to perform alias-analysis. */
   updateBindings(
     functionAst_: Ast.Function,
-    rawFunction: RawAst.Tree.Function,
+    rawFunction: RawAst.Tree.Function | undefined,
     moduleCode: string,
     getSpan: (id: AstId) => SourceRange | undefined,
   ) {

app/gui2/src/stores/graph/index.ts

@@ -179,7 +179,6 @@ export const { injectFn: useGraphStore, provideFn: provideGraphStore } = createC
       const methodSpan = moduleSource.getSpan(method.id)
       assert(methodSpan != null)
       const rawFunc = toRaw.get(sourceRangeKey(methodSpan))
-      assert(rawFunc != null)
       const getSpan = (id: AstId) => moduleSource.getSpan(id)
       db.updateBindings(method, rawFunc, moduleSource.text, getSpan)
     })

app/gui2/src/util/database/reactiveDb.ts

@@ -15,7 +15,15 @@ import { LazySyncEffectSet, NonReactiveView } from '@/util/reactivity'
 import * as map from 'lib0/map'
 import { ObservableV2 } from 'lib0/observable'
 import * as set from 'lib0/set'
-import { computed, effectScope, reactive, toRaw, type ComputedRef, type DebuggerOptions } from 'vue'
+import {
+  computed,
+  effectScope,
+  onScopeDispose,
+  reactive,
+  toRaw,
+  type ComputedRef,
+  type DebuggerOptions,
+} from 'vue'
 
 export type OnDelete = (cleanupFn: () => void) => void
 
@@ -218,14 +226,18 @@ export class ReactiveIndex<K, V, IK, IV> {
   constructor(db: ReactiveDb<K, V>, indexer: Indexer<K, V, IK, IV>) {
     this.forward = reactive(map.create())
     this.reverse = reactive(map.create())
-    this.effects = new LazySyncEffectSet()
-    db.on('entryAdded', (key, value, onDelete) => {
-      const stopEffect = this.effects.lazyEffect((onCleanup) => {
-        const keyValues = indexer(key, value)
-        keyValues.forEach(([key, value]) => this.writeToIndex(key, value))
-        onCleanup(() => keyValues.forEach(([key, value]) => this.removeFromIndex(key, value)))
+    const scope = effectScope()
+    this.effects = new LazySyncEffectSet(scope)
+    scope.run(() => {
+      const handler = db.on('entryAdded', (key, value, onDelete) => {
+        const stopEffect = this.effects.lazyEffect((onCleanup) => {
+          const keyValues = indexer(key, value)
+          keyValues.forEach(([key, value]) => this.writeToIndex(key, value))
+          onCleanup(() => keyValues.forEach(([key, value]) => this.removeFromIndex(key, value)))
+        })
+        onDelete(() => stopEffect())
       })
-      onDelete(() => stopEffect())
+      onScopeDispose(() => db.off('entryAdded', handler))
     })
   }
 
@@ -353,16 +365,20 @@ export class ReactiveMapping<K, V, M> {
    */
   constructor(db: ReactiveDb<K, V>, indexer: Mapper<K, V, M>, debugOptions?: DebuggerOptions) {
     this.computed = reactive(map.create())
-    db.on('entryAdded', (key, value, onDelete) => {
-      const scope = effectScope()
-      const mappedValue = scope.run(() =>
-        computed(() => scope.run(() => indexer(key, value)), debugOptions),
-      )! // This non-null assertion is SAFE, as the scope is initially active.
-      this.computed.set(key, mappedValue)
-      onDelete(() => {
-        scope.stop()
-        this.computed.delete(key)
+    const scope = effectScope()
+    scope.run(() => {
+      const handler = db.on('entryAdded', (key, value, onDelete) => {
+        const scope = effectScope()
+        const mappedValue = scope.run(() =>
+          computed(() => scope.run(() => indexer(key, value)), debugOptions),
+        )! // This non-null assertion is SAFE, as the scope is initially active.
+        this.computed.set(key, mappedValue)
+        onDelete(() => {
+          scope.stop()
+          this.computed.delete(key)
+        })
       })
+      onScopeDispose(() => db.off('entryAdded', handler))
     })
   }
 

app/gui2/src/util/reactivity.ts

@@ -45,9 +45,10 @@ export type StopEffect = () => void
  */
 export class LazySyncEffectSet {
   _dirtyRunners = new Set<() => void>()
-  _scope = effectScope()
   _boundFlush = this.flush.bind(this)
 
+  constructor(private _scope = effectScope()) {}
+
   /**
    * Add an effect to the lazy set. The effect will run once immediately, and any subsequent runs
    * will be delayed until the next flush. Only effects that were notified about a dependency change

app/ydoc-shared/src/ast/parse.ts

@@ -668,6 +668,8 @@ function checkSpans(expected: NodeSpanMap, encountered: NodeSpanMap, code: strin
   const lostBlock = new Array<Ast>()
   for (const [key, ast] of lost) {
     const [start, end] = sourceRangeFromKey(key)
+    // Do not report lost empty body blocks, we don't want them to be considered for repair.
+    if (start === end && ast instanceof BodyBlock) continue
     ;(code.substring(start, end).match(/[\r\n]/) ? lostBlock : lostInline).push(ast)
   }
   return { lostInline, lostBlock }

app/ydoc-shared/src/ast/tree.ts

@@ -1962,6 +1962,7 @@ export class MutableFunction extends Function implements MutableAst {
     if (oldBody instanceof MutableBodyBlock) return oldBody
     const newBody = BodyBlock.new([], this.module)
     if (oldBody) newBody.push(oldBody.take())
+    this.setBody(newBody)
     return newBody
   }
 }