feat(language-service): expose determining the NgModule of a Directive (#32710)

This sets up the Language Service to support #32565.
This PR exposes a `getDirectiveModule` method on `TypeScriptServiceHost`
that returns the NgModule owning a Directive given the Directive's
TypeScript node or its Angular `StaticSymbol`. Both types are supported
to reduce extraneous helper methods.

PR Close #32710

packages/language-service/src/typescript_host.ts

@@ -441,6 +441,14 @@ export class TypeScriptServiceHost implements LanguageServiceHost {
     return astResult;
   }
 
+  /**
+   * Gets a StaticSymbol from a file and symbol name.
+   * @return Angular StaticSymbol matching the file and name, if any
+   */
+  getStaticSymbol(file: string, name: string): StaticSymbol|undefined {
+    return this.reflector.getStaticSymbol(file, name);
+  }
+
   /**
    * Find the NgModule which the directive associated with the `classSymbol`
    * belongs to, then return its schema and transitive directives and pipes.

packages/language-service/test/typescript_host_spec.ts

@@ -170,4 +170,24 @@ describe('TypeScriptServiceHost', () => {
     const newModules = ngLSHost.getAnalyzedModules();
     expect(newModules).toBe(oldModules);
   });
+
+  it('should get the correct StaticSymbol for a Directive', () => {
+    const tsLSHost = new MockTypescriptHost(['/app/app.component.ts', '/app/main.ts'], toh);
+    const tsLS = ts.createLanguageService(tsLSHost);
+    const ngLSHost = new TypeScriptServiceHost(tsLSHost, tsLS);
+    ngLSHost.getAnalyzedModules();  // modules are analyzed lazily
+    const sf = ngLSHost.getSourceFile('/app/app.component.ts');
+    expect(sf).toBeDefined();
+    const directiveDecl = sf !.forEachChild(n => {
+      if (ts.isClassDeclaration(n) && n.name && n.name.text === 'AppComponent') return n;
+    });
+
+    expect(directiveDecl).toBeDefined();
+    expect(directiveDecl !.name).toBeDefined();
+    const fileName = directiveDecl !.getSourceFile().fileName;
+    const symbolName = directiveDecl !.name !.getText();
+    const directiveSymbol = ngLSHost.getStaticSymbol(fileName, symbolName);
+    expect(directiveSymbol).toBeDefined();
+    expect(directiveSymbol !.name).toBe('AppComponent');
+  });
 });