feat(language-service): completions support for tuple array (#33928)

PR Close #33928

packages/language-service/test/completions_spec.ts

@@ -125,6 +125,13 @@ describe('completions', () => {
       expectContain(completions, CompletionKind.PROPERTY, ['id', 'name']);
     });
 
+    it('should work with numeric index signatures (tuple arrays)', () => {
+      mockHost.override(TEST_TEMPLATE, `{{ tupleArray[1].~{tuple-array-number-index}}}`);
+      const marker = mockHost.getLocationMarkerFor(TEST_TEMPLATE, 'tuple-array-number-index');
+      const completions = ngLS.getCompletionsAt(TEST_TEMPLATE, marker.start);
+      expectContain(completions, CompletionKind.PROPERTY, ['id', 'name']);
+    });
+
     describe('with string index signatures', () => {
       it('should work with index notation', () => {
         mockHost.override(TEST_TEMPLATE, `{{ heroesByName['Jacky'].~{heroes-string-index}}}`);

packages/language-service/test/diagnostics_spec.ts

@@ -150,6 +150,15 @@ describe('diagnostics', () => {
     });
   });
 
+  it('should produce diagnostics for invalid tuple type property access', () => {
+    mockHost.override(TEST_TEMPLATE, `
+        {{tupleArray[1].badProperty}}`);
+    const diags = ngLS.getDiagnostics(TEST_TEMPLATE);
+    expect(diags.length).toBe(1);
+    expect(diags[0].messageText)
+        .toBe(`Identifier 'badProperty' is not defined. 'Hero' does not contain such a member`);
+  });
+
   it('should not produce errors on function.bind()', () => {
     mockHost.override(TEST_TEMPLATE, `
       <test-comp (test)="myClick.bind(this)">

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

@@ -189,6 +189,7 @@ export class TemplateReference {
   title = 'Some title';
   hero: Hero = {id: 1, name: 'Windstorm'};
   heroes: Hero[] = [this.hero];
+  tupleArray: [string, Hero] = ['test', this.hero];
   league: Hero[][] = [this.heroes];
   heroesByName: {[name: string]: Hero} = {};
   anyValue: any;