fix(language-service): bug of accessing a string index signature using dot notation (#34177)

PR Close #34177

packages/language-service/src/typescript_symbols.ts

@@ -308,6 +308,10 @@ class TypeWrapper implements Symbol {
   }
 }
 
+class StringIndexTypeWrappr extends TypeWrapper {
+  public readonly type = new TypeWrapper(this.tsType, this.context);
+}
+
 class SymbolWrapper implements Symbol {
   private symbol: ts.Symbol;
   private _members?: SymbolTable;
@@ -506,10 +510,11 @@ class SymbolTableWrapper implements SymbolTable {
       //   obj.stringIndex // equivalent to obj['stringIndex'];
       //
       // In this case, return the type indexed by an arbitrary string key.
-      const symbol = this.stringIndexType.getSymbol();
-      if (symbol) {
-        return new SymbolWrapper(symbol, this.context, this.stringIndexType);
-      }
+
+      // if stringIndexType is js primitive type(e.g. 'string'), the Symbol is undefined;
+      // and In AstType.resolvePropertyRead method, the Symbol.type should get the right type.
+      // so I add a new Symbol type, 'StringIndexTypeWrappr'
+      return new StringIndexTypeWrappr(this.stringIndexType, this.context);
     }
 
     return undefined;

packages/language-service/test/diagnostics_spec.ts

@@ -172,6 +172,14 @@ describe('diagnostics', () => {
         expect(diags[0].messageText)
             .toBe(`Identifier 'badProperty' is not defined. 'Hero' does not contain such a member`);
       });
+
+      it('should not produce errors with dot notation if stringIndexType is js primitive type',
+         () => {
+           mockHost.override(TEST_TEMPLATE, `
+        {{primitiveType.test}}`);
+           const diags = ngLS.getDiagnostics(TEST_TEMPLATE);
+           expect(diags.length).toBe(0);
+         });
     });
   });
 

packages/language-service/test/project/app/parsing-cases.ts

@@ -192,6 +192,7 @@ export class TemplateReference {
   tupleArray: [string, Hero] = ['test', this.hero];
   league: Hero[][] = [this.heroes];
   heroesByName: {[name: string]: Hero} = {};
+  primitiveType: {[name: string]: string} = {};
   anyValue: any;
   myClick(event: any) {}
 }