fix(language-service): break the hover/definitions for two-way binding (#34564)

PR Close #34564

Author: ivanwonder

packages/language-service/src/locate_symbol.ts

@@ -6,7 +6,7 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import {AST, Attribute, BoundDirectivePropertyAst, BoundEventAst, CompileTypeSummary, CssSelector, DirectiveAst, ElementAst, SelectorMatcher, TemplateAstPath, tokenReference} from '@angular/compiler';
+import {AST, Attribute, BoundDirectivePropertyAst, BoundEventAst, CompileTypeSummary, CssSelector, DirectiveAst, ElementAst, RecursiveTemplateAstVisitor, SelectorMatcher, TemplateAst, TemplateAstPath, templateVisitAll, tokenReference} from '@angular/compiler';
 
 import {AstResult} from './common';
 import {getExpressionScope} from './expression_diagnostics';
@@ -148,14 +148,31 @@ function findAttribute(info: AstResult, position: number): Attribute|undefined {
   return path.first(Attribute);
 }
 
+function findParentOfDirectivePropertyAst(ast: TemplateAst[], binding: BoundDirectivePropertyAst) {
+  let res: DirectiveAst|undefined;
+  const visitor = new class extends RecursiveTemplateAstVisitor {
+    visitDirective(ast: DirectiveAst) {
+      const result = this.visitChildren(ast, visit => { visit(ast.inputs); });
+      return result;
+    }
+    visitDirectiveProperty(ast: BoundDirectivePropertyAst, context: any) {
+      if (ast === binding) {
+        res = context;
+      }
+    }
+  };
+  templateVisitAll(visitor, ast);
+  return res;
+}
+
 function findInputBinding(
     info: AstResult, path: TemplateAstPath, binding: BoundDirectivePropertyAst): Symbol|undefined {
-  const directive = path.parentOf(path.tail);
-  if (directive instanceof DirectiveAst) {
-    const invertedInput = invertMap(directive.directive.inputs);
+  const directiveAst = findParentOfDirectivePropertyAst(info.templateAst, binding);
+  if (directiveAst) {
+    const invertedInput = invertMap(directiveAst.directive.inputs);
     const fieldName = invertedInput[binding.templateName];
     if (fieldName) {
-      const classSymbol = info.template.query.getTypeSymbol(directive.directive.type.reference);
+      const classSymbol = info.template.query.getTypeSymbol(directiveAst.directive.type.reference);
       if (classSymbol) {
         return classSymbol.members().get(fieldName);
       }

packages/language-service/test/definitions_spec.ts

@@ -291,6 +291,42 @@ describe('definitions', () => {
     // Not asserting the textSpan of definition because it's external file
   });
 
+  it('should be able to find a two-way binding', () => {
+    const fileName = mockHost.addCode(`
+      @Component({
+        template: '<test-comp string-model ~{start-my}[(«model»)]="test"~{end-my}></test-comp>'
+      })
+      export class MyComponent {
+        test = "";
+      }`);
+    // Get the marker for «model» in the code added above.
+    const marker = mockHost.getReferenceMarkerFor(fileName, 'model');
+
+    const result = ngService.getDefinitionAt(fileName, marker.start);
+    expect(result).toBeDefined();
+    const {textSpan, definitions} = result !;
+
+    // Get the marker for bounded text in the code added above
+    const boundedText = mockHost.getLocationMarkerFor(fileName, 'my');
+    expect(textSpan).toEqual(boundedText);
+
+    // There should be exactly 1 definition
+    expect(definitions).toBeDefined();
+    expect(definitions !.length).toBe(1);
+    const def = definitions ![0];
+
+    const refFileName = '/app/parsing-cases.ts';
+    expect(def.fileName).toBe(refFileName);
+    expect(def.name).toBe('model');
+    expect(def.kind).toBe('property');
+    const content = mockHost.readFile(refFileName) !;
+    const ref = `@Input() model: string = 'model';`;
+    expect(def.textSpan).toEqual({
+      start: content.indexOf(ref),
+      length: ref.length,
+    });
+  });
+
   it('should be able to find a template from a url', () => {
     const fileName = mockHost.addCode(`
 	      @Component({

packages/language-service/test/hover_spec.ts

@@ -162,6 +162,22 @@ describe('hover', () => {
     expect(toText(displayParts)).toBe('(property) NgIf<T>.ngIf: T');
   });
 
+  it('should be able to find a reference to a two-way binding', () => {
+    const fileName = mockHost.addCode(`
+      @Component({
+        template: '<test-comp string-model «[(ᐱmodelᐱ)]="test"»></test-comp>'
+      })
+      export class MyComponent {
+        test = "";
+      }`);
+    const marker = mockHost.getDefinitionMarkerFor(fileName, 'model');
+    const quickInfo = ngLS.getHoverAt(fileName, marker.start);
+    expect(quickInfo).toBeTruthy();
+    const {textSpan, displayParts} = quickInfo !;
+    expect(textSpan).toEqual(marker);
+    expect(toText(displayParts)).toBe('(property) StringModel.model: string');
+  });
+
   it('should be able to ignore a reference declaration', () => {
     const fileName = mockHost.addCode(`
       @Component({