feat(language-service): support to fix invalid banana in box

The Angular compiler will report the invalid banana in box, this code fixes
will try to fix the error and all the same errors in the selected file.

packages/language-service/src/codefixes/all_codefixes_metas.ts

@@ -6,7 +6,11 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
+import {fixInvalidBananaInBoxMeta} from './fix_invalid_banana_in_box';
 import {missingMemberMeta} from './fix_missing_member';
 import {CodeActionMeta} from './utils';
 
-export const ALL_CODE_FIXES_METAS: CodeActionMeta[] = [missingMemberMeta];
+export const ALL_CODE_FIXES_METAS: CodeActionMeta[] = [
+  missingMemberMeta,
+  fixInvalidBananaInBoxMeta,
+];

packages/language-service/src/codefixes/code_fixes.ts

@@ -98,7 +98,8 @@ export class CodeFixes {
       preferences,
       tsLs: this.tsLS,
       scope,
-      diagnostics,
+      // only pass the diagnostics the `meta` cares about.
+      diagnostics: diagnostics.filter(diag => meta.errorCodes.includes(diag.code)),
     });
   }
 }

packages/language-service/src/codefixes/fix_invalid_banana_in_box.ts

@@ -0,0 +1,128 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+import {ErrorCode, ngErrorCode} from '@angular/compiler-cli/src/ngtsc/diagnostics';
+import {isExternalResource} from '@angular/compiler-cli/src/ngtsc/metadata';
+import {BoundEvent} from '@angular/compiler/src/render3/r3_ast';
+import * as tss from 'typescript/lib/tsserverlibrary';
+
+import {getTargetAtPosition, TargetNodeKind} from '../template_target';
+import {getTemplateInfoAtPosition, TemplateInfo} from '../utils';
+
+import {CodeActionMeta, FixIdForCodeFixesAll} from './utils';
+
+/**
+ * fix [invalid banana-in-box](https://angular.io/extended-diagnostics/NG8101)
+ */
+export const fixInvalidBananaInBoxMeta: CodeActionMeta = {
+  errorCodes: [ngErrorCode(ErrorCode.INVALID_BANANA_IN_BOX)],
+  getCodeActions({start, templateInfo, compiler}) {
+    const resource = compiler.getComponentResources(templateInfo.component)?.template;
+    if (resource === undefined) {
+      return [];
+    }
+
+    let fileName = resource.expression.getSourceFile().fileName;
+    if (isExternalResource(resource)) {
+      fileName = resource.path;
+    }
+
+    const boundEvent = getTheBoundEventAtPosition(templateInfo, start);
+    if (boundEvent === null) {
+      return [];
+    }
+    const textChanges = convertBoundEventToTsTextChange(boundEvent);
+    return [{
+      fixName: FixIdForCodeFixesAll.FIX_INVALID_BANANA_IN_BOX,
+      fixId: FixIdForCodeFixesAll.FIX_INVALID_BANANA_IN_BOX,
+      fixAllDescription: 'fix all invalid banana-in-box',
+      description: `fix invalid banana-in-box for '${boundEvent.sourceSpan.toString()}'`,
+      changes: [{
+        fileName,
+        textChanges,
+      }],
+    }];
+  },
+  fixIds: [FixIdForCodeFixesAll.FIX_INVALID_BANANA_IN_BOX],
+  getAllCodeActions({diagnostics, compiler}) {
+    const fileNameToTextChangesMap = new Map<string, tss.TextChange[]>();
+    for (const diag of diagnostics) {
+      const fileName = diag.file?.fileName;
+      if (fileName === undefined) {
+        continue;
+      }
+      const start = diag.start;
+      if (start === undefined) {
+        continue;
+      }
+      const templateInfo = getTemplateInfoAtPosition(fileName, start, compiler);
+      if (templateInfo === undefined) {
+        continue;
+      }
+      const boundEvent = getTheBoundEventAtPosition(templateInfo, start);
+      if (boundEvent === null) {
+        continue;
+      }
+
+      if (!fileNameToTextChangesMap.has(fileName)) {
+        fileNameToTextChangesMap.set(fileName, []);
+      }
+      const fileTextChanges = fileNameToTextChangesMap.get(fileName)!;
+      const textChanges = convertBoundEventToTsTextChange(boundEvent);
+      fileTextChanges.push(...textChanges);
+    }
+
+    const fileTextChanges: tss.FileTextChanges[] = [];
+    for (const [fileName, textChanges] of fileNameToTextChangesMap) {
+      fileTextChanges.push({
+        fileName,
+        textChanges,
+      });
+    }
+    return {
+      changes: fileTextChanges,
+    };
+  },
+};
+
+function getTheBoundEventAtPosition(templateInfo: TemplateInfo, start: number): BoundEvent|null {
+  // It's safe to get the bound event at the position `start + 1` because the `start` is at the
+  // start of the diagnostic, and the node outside the attribute key and value spans are skipped by
+  // the function `getTargetAtPosition`.
+  // https://github.com/angular/vscode-ng-language-service/blob/8553115972ca40a55602747667c3d11d6f47a6f8/server/src/session.ts#L220
+  // https://github.com/angular/angular/blob/4e10a7494130b9bb4772ee8f76b66675867b2145/packages/language-service/src/template_target.ts#L347-L356
+  const positionDetail = getTargetAtPosition(templateInfo.template, start + 1);
+  if (!positionDetail) {
+    return null;
+  }
+
+  let node: BoundEvent|null = null;
+
+  if (positionDetail.context.kind === TargetNodeKind.AttributeInKeyContext &&
+      positionDetail.context.node instanceof BoundEvent) {
+    node = positionDetail.context.node;
+  }
+
+  return node;
+}
+
+function convertBoundEventToTsTextChange(node: BoundEvent): readonly tss.TextChange[] {
+  const name = node.name;
+  const boundSyntax = node.sourceSpan.toString();
+  const expectedBoundSyntax = boundSyntax.replace(`(${name})`, `[(${name.slice(1, -1)})]`);
+
+  return [
+    {
+      span: {
+        start: node.sourceSpan.start.offset,
+        length: boundSyntax.length,
+      },
+      newText: expectedBoundSyntax,
+    },
+  ];
+}

packages/language-service/src/codefixes/utils.ts

@@ -132,4 +132,5 @@ export function isFixAllAvailable(meta: CodeActionMeta, diagnostics: tss.Diagnos
 export enum FixIdForCodeFixesAll {
   FIX_SPELLING = 'fixSpelling',
   FIX_MISSING_MEMBER = 'fixMissingMember',
+  FIX_INVALID_BANANA_IN_BOX = 'fixInvalidBananaInBox',
 }

packages/language-service/test/code_fixes_spec.ts

@@ -8,6 +8,7 @@
 
 import {initMockFileSystem} from '@angular/compiler-cli/src/ngtsc/file_system/testing';
 
+import {FixIdForCodeFixesAll} from '../src/codefixes/utils';
 import {createModuleAndProjectWithDeclarations, LanguageServiceTestEnv} from '../testing';
 
 describe('code fixes', () => {
@@ -157,6 +158,74 @@ describe('code fixes', () => {
       fileName: 'app.ts'
     });
   });
+
+  it('should fix invalid banana-in-box error', () => {
+    const files = {
+      'app.ts': `
+      import {Component, NgModule} from '@angular/core';
+
+      @Component({
+        templateUrl: './app.html'
+      })
+      export class AppComponent {
+        title = '';
+      }
+    `,
+      'app.html': `<input ([ngModel])="title">`,
+    };
+
+    const project = createModuleAndProjectWithDeclarations(env, 'test', files);
+    const diags = project.getDiagnosticsForFile('app.html');
+    const appFile = project.openFile('app.html');
+    appFile.moveCursorToText('¦([ngModel');
+
+    const codeActions =
+        project.getCodeFixesAtPosition('app.html', appFile.cursor, appFile.cursor, [diags[0].code]);
+    expectIncludeReplacementText({
+      codeActions,
+      content: appFile.contents,
+      text: `([ngModel])="title"`,
+      newText: `[(ngModel)]="title"`,
+      fileName: 'app.html',
+      description: `fix invalid banana-in-box for '([ngModel])="title"'`
+    });
+  });
+
+  it('should fix all invalid banana-in-box errors', () => {
+    const files = {
+      'app.ts': `
+      import {Component, NgModule} from '@angular/core';
+
+      @Component({
+        template: '<input ([ngModel])="title"><input ([value])="title">',
+      })
+      export class AppComponent {
+        title = '';
+        banner = '';
+      }
+    `,
+    };
+
+    const project = createModuleAndProjectWithDeclarations(env, 'test', files);
+    const appFile = project.openFile('app.ts');
+
+    const fixesAllActions =
+        project.getCombinedCodeFix('app.ts', FixIdForCodeFixesAll.FIX_INVALID_BANANA_IN_BOX);
+    expectIncludeReplacementTextForFileTextChange({
+      fileTextChanges: fixesAllActions.changes,
+      content: appFile.contents,
+      text: `([ngModel])="title"`,
+      newText: `[(ngModel)]="title"`,
+      fileName: 'app.ts'
+    });
+    expectIncludeReplacementTextForFileTextChange({
+      fileTextChanges: fixesAllActions.changes,
+      content: appFile.contents,
+      text: `([value])="title"`,
+      newText: `[(value)]="title"`,
+      fileName: 'app.ts'
+    });
+  });
 });
 
 function expectNotIncludeFixAllInfo(codeActions: readonly ts.CodeFixAction[]) {
@@ -166,14 +235,22 @@ function expectNotIncludeFixAllInfo(codeActions: readonly ts.CodeFixAction[]) {
   }
 }
 
-function expectIncludeReplacementText({codeActions, content, text, newText, fileName}: {
-  codeActions: readonly ts.CodeAction[]; content: string; text: string; newText: string;
-  fileName: string;
-}) {
+/**
+ * The `description` is optional because if the description comes from the ts server, no need to
+ * check it.
+ */
+function expectIncludeReplacementText(
+    {codeActions, content, text, newText, fileName, description}: {
+      codeActions: readonly ts.CodeAction[]; content: string; text: string; newText: string;
+      fileName: string;
+      description?: string;
+    }) {
   let includeReplacementText = false;
   for (const codeAction of codeActions) {
-    includeReplacementText = includeReplacementTextInChanges(
-        {fileTextChanges: codeAction.changes, content, text, newText, fileName});
+    includeReplacementText =
+        includeReplacementTextInChanges(
+            {fileTextChanges: codeAction.changes, content, text, newText, fileName}) &&
+        (description === undefined ? true : (description === codeAction.description));
     if (includeReplacementText) {
       return;
     }