Drop dangling local symbol occurrences

Amp-Thread-ID: https://ampcode.com/threads/T-01a029e2-5095-710a-9cce-0c6d8645c173

Author: eseliger

snapshots/input/multi-project/packages/a/src/index.ts

@@ -3,3 +3,10 @@
 export function a(): string {
   return ''
 }
+
+export function localResult() {
+  interface LocalResult {
+    value: string
+  }
+  return { value: '' } as LocalResult
+}

snapshots/input/multi-project/packages/b/src/b.ts

@@ -1,5 +1,6 @@
-import { a } from '@example/a/src'
+import { a, localResult } from '@example/a/src'
 
 export function b() {
+  localResult().value
   return a()
 }

snapshots/output/multi-project/packages/a/src/index.ts

@@ -14,3 +14,24 @@ export function a(): string {
   return ''
 }
 
+export function localResult() {
+//              ^^^^^^^^^^^ definition @example/a 1.0.0 src/`index.ts`/localResult().
+//              documentation ```ts
+//                          > function localResult(): LocalResult
+//                          > ```
+  interface LocalResult {
+//          ^^^^^^^^^^^ definition local 0
+//          documentation ```ts
+//                      > interface LocalResult
+//                      > ```
+    value: string
+//  ^^^^^ definition local 1
+//  documentation ```ts
+//              > (property) value: string
+//              > ```
+  }
+  return { value: '' } as LocalResult
+//         ^^^^^ reference local 1
+//                        ^^^^^^^^^^^ reference local 0
+}
+

snapshots/output/multi-project/packages/b/src/b.ts

@@ -1,12 +1,15 @@
 // language TypeScript
 // < definition @example/b 1.0.0 src/`b.ts`/
 
-import { a } from '@example/a/src'
+import { a, localResult } from '@example/a/src'
 //       ^ reference @example/a 1.0.0 src/`index.ts`/a().
-//                ^^^^^^^^^^^^^^^^ reference @example/a 1.0.0 src/`index.ts`/
+//          ^^^^^^^^^^^ reference @example/a 1.0.0 src/`index.ts`/localResult().
+//                             ^^^^^^^^^^^^^^^^ reference @example/a 1.0.0 src/`index.ts`/
 
 export function b() {
 //              ^ definition @example/b 1.0.0 src/`b.ts`/b().
+  localResult().value
+//^^^^^^^^^^^ reference @example/a 1.0.0 src/`index.ts`/localResult().
   return a()
 //       ^ reference @example/a 1.0.0 src/`index.ts`/a().
 }

src/FileIndexer.ts

@@ -65,6 +65,34 @@ export class FileIndexer {
 
     this.emitSourceFileOccurrence()
     this.visit(this.sourceFile)
+    const missingLocalDefinition = this.document.occurrences.find(
+      occurrence =>
+        occurrence.symbol.startsWith('local ') &&
+        (occurrence.symbol_roles & scip.scip.SymbolRole.Definition) !== 0 &&
+        !this.symbolInformation.has(occurrence.symbol)
+    )
+    if (missingLocalDefinition) {
+      throw new Error(
+        `local definition '${missingLocalDefinition.symbol}' has no SymbolInformation in '${this.document.relative_path}'`
+      )
+    }
+    // A SCIP local symbol is owned by one document. TypeScript can report
+    // synthetic or cross-file declaration candidates that the symbol algorithm
+    // cannot represent as locals in this document, so discard those unusable
+    // occurrences instead of emitting dangling local identities.
+    this.document.occurrences = this.document.occurrences.filter(
+      occurrence =>
+        !occurrence.symbol.startsWith('local ') ||
+        this.symbolInformation.has(occurrence.symbol)
+    )
+    // Relationships to locals have the same document-local ownership rule.
+    for (const symbol of this.document.symbols) {
+      symbol.relationships = symbol.relationships.filter(
+        relationship =>
+          !relationship.symbol.startsWith('local ') ||
+          this.symbolInformation.has(relationship.symbol)
+      )
+    }
   }
   private emitSourceFileOccurrence(): void {
     const symbol = this.scipSymbol(this.sourceFile)

src/main.test.ts

@@ -145,22 +145,24 @@ for (const snapshotDirectory of snapshotDirectories) {
         .filter(
           symbol =>
             symbol &&
-            !symbol.startsWith('local ') &&
-            !availableSymbols.has(symbol)
+            (symbol.startsWith('local ')
+              ? !symbols.has(symbol)
+              : !availableSymbols.has(symbol))
         )
       assert.equal(
         missingOccurrenceSymbols,
         [],
-        `${document.relative_path} global occurrences should have SymbolInformation`
+        `${document.relative_path} occurrences should have SymbolInformation`
       )
       const missingRelationshipSymbols = document.symbols
         .flatMap(symbol => symbol.relationships)
         .map(relationship => relationship.symbol)
         .filter(
           symbol =>
             symbol &&
-            !symbol.startsWith('local ') &&
-            !availableSymbols.has(symbol)
+            (symbol.startsWith('local ')
+              ? !symbols.has(symbol)
+              : !availableSymbols.has(symbol))
         )
       assert.equal(
         missingRelationshipSymbols,