fix(language-service): remove repeated symbol definitions for structural directive (#34847)

For the structural directive, the 'path' will contain multiple `BoundDirectivePropertyAst` which depends on the number of directive property in the attribute value(e.g. '*ngFor="let item of []; trackBy: test;"', it has 2 `BoundDirectivePropertyAst`, 'ngForOf' and 'ngForTrackBy').

PR Close #34847

packages/language-service/src/locate_symbol.ts

@@ -29,6 +29,8 @@ export function locateSymbols(info: AstResult, position: number): SymbolInfo[] {
   const templatePosition = position - info.template.span.start;
   // TODO: update `findTemplateAstAt` to use absolute positions.
   const path = findTemplateAstAt(info.templateAst, templatePosition);
+  const attribute = findAttribute(info, position);
+
   if (!path.tail) return [];
 
   const narrowest = spanOf(path.tail);
@@ -38,6 +40,11 @@ export function locateSymbols(info: AstResult, position: number): SymbolInfo[] {
     toVisit.push(node);
   }
 
+  // For the structural directive, only care about the last template AST.
+  if (attribute?.name.startsWith('*')) {
+    toVisit.splice(0, toVisit.length - 1);
+  }
+
   return toVisit.map(ast => locateSymbol(ast, path, info))
       .filter((sym): sym is SymbolInfo => sym !== undefined);
 }

packages/language-service/test/definitions_spec.ts

@@ -311,7 +311,7 @@ describe('definitions', () => {
 
       expect(definitions).toBeDefined();
       // The two definitions are setter and getter of 'ngForTrackBy'.
-      expect(definitions !.length).toBe(4);
+      expect(definitions !.length).toBe(2);
 
       const refFileName = '/node_modules/@angular/common/common.d.ts';
       definitions !.forEach(def => {
@@ -335,7 +335,7 @@ describe('definitions', () => {
       expect(textSpan).toEqual(marker);
 
       expect(definitions).toBeDefined();
-      expect(definitions !.length).toBe(2);
+      expect(definitions !.length).toBe(1);
 
       const refFileName = '/app/parsing-cases.ts';
       const def = definitions ![0];