angular · crisbeto · Oct 29, 2024
diff --git a/packages/compiler-cli/src/ngtsc/annotations/common/src/standalone-default-value.ts b/packages/compiler-cli/src/ngtsc/annotations/common/src/standalone-default-value.ts
diff --git a/packages/compiler-cli/src/ngtsc/annotations/component/src/handler.ts b/packages/compiler-cli/src/ngtsc/annotations/component/src/handler.ts
@@ -258,6 +258,7 @@ export class ComponentDecoratorHandler
     private readonly i18nPreserveSignificantWhitespace: boolean,
     private readonly strictStandalone: boolean,
     private readonly enableHmr: boolean,
+    private readonly implicitStandaloneValue: boolean,
   ) {
     this.extractTemplateOptions = {
       enableI18nLegacyMessageIdFormat: this.enableI18nLegacyMessageIdFormat,
@@ -464,6 +465,7 @@ export class ComponentDecoratorHandler
       this.compilationMode,
       this.elementSchemaRegistry.getDefaultComponentElementName(),
       this.strictStandalone,
+      this.implicitStandaloneValue,
     );
     // `extractDirectiveMetadata` returns `jitForced = true` when the `@Component` has
     // set `jit: true`. In this case, compilation of the decorator is skipped. Returning

diff --git a/packages/compiler-cli/src/ngtsc/annotations/component/test/component_spec.ts b/packages/compiler-cli/src/ngtsc/annotations/component/test/component_spec.ts
@@ -159,6 +159,7 @@ function setup(
     /* i18nPreserveSignificantWhitespace */ true,
     /* strictStandalone */ false,
     /* enableHmr */ false,
+    /* implicitStandaloneValue */ true,
   );
   return {reflectionHost, handler, resourceLoader, metaRegistry};
 }

diff --git a/packages/compiler-cli/src/ngtsc/annotations/directive/src/handler.ts b/packages/compiler-cli/src/ngtsc/annotations/directive/src/handler.ts
@@ -137,6 +137,7 @@ export class DirectiveDecoratorHandler
     private readonly compilationMode: CompilationMode,
     private readonly jitDeclarationRegistry: JitDeclarationRegistry,
     private readonly strictStandalone: boolean,
+    private readonly implicitStandaloneValue: boolean,
   ) {}
 
   readonly precedence = HandlerPrecedence.PRIMARY;
@@ -192,6 +193,7 @@ export class DirectiveDecoratorHandler
       this.compilationMode,
       /* defaultSelector */ null,
       this.strictStandalone,
+      this.implicitStandaloneValue,
     );
     // `extractDirectiveMetadata` returns `jitForced = true` when the `@Directive` has
     // set `jit: true`. In this case, compilation of the decorator is skipped. Returning

diff --git a/packages/compiler-cli/src/ngtsc/annotations/directive/src/shared.ts b/packages/compiler-cli/src/ngtsc/annotations/directive/src/shared.ts
@@ -84,7 +84,6 @@ import {tryParseSignalInputMapping} from './input_function';
 import {tryParseSignalModelMapping} from './model_function';
 import {tryParseInitializerBasedOutput} from './output_function';
 import {tryParseSignalQueryFromInitializer} from './query_functions';
-import {NG_STANDALONE_DEFAULT_VALUE} from '../../common/src/standalone-default-value';
 
 const EMPTY_OBJECT: {[key: string]: string} = {};
 
@@ -117,6 +116,7 @@ export function extractDirectiveMetadata(
   compilationMode: CompilationMode,
   defaultSelector: string | null,
   strictStandalone: boolean,
+  implicitStandaloneValue: boolean,
 ):
   | {
       jitForced: false;
@@ -336,7 +336,7 @@ export function extractDirectiveMetadata(
         dep.token.value.name === 'TemplateRef',
     );
 
-  let isStandalone = NG_STANDALONE_DEFAULT_VALUE;
+  let isStandalone = implicitStandaloneValue;
   if (directive.has('standalone')) {
     const expr = directive.get('standalone')!;
     const resolved = evaluator.evaluate(expr);

diff --git a/packages/compiler-cli/src/ngtsc/annotations/directive/test/directive_spec.ts b/packages/compiler-cli/src/ngtsc/annotations/directive/test/directive_spec.ts
@@ -215,6 +215,7 @@ runInEachFileSystem(() => {
       /*compilationMode */ CompilationMode.FULL,
       jitDeclarationRegistry,
       /* strictStandalone */ false,
+      /* implicitStandaloneValue */ true,
     );
 
     const DirNode = getDeclaration(program, _('/entry.ts'), dirName, isNamedClassDeclaration);

diff --git a/packages/compiler-cli/src/ngtsc/annotations/src/pipe.ts b/packages/compiler-cli/src/ngtsc/annotations/src/pipe.ts
@@ -49,7 +49,6 @@ import {
   unwrapExpression,
   wrapTypeReference,
 } from '../common';
-import {NG_STANDALONE_DEFAULT_VALUE} from '../common/src/standalone-default-value';
 
 export interface PipeHandlerData {
   meta: R3PipeMetadata;
@@ -97,6 +96,7 @@ export class PipeDecoratorHandler
     private readonly compilationMode: CompilationMode,
     private readonly generateExtraImportsInLocalMode: boolean,
     private readonly strictStandalone: boolean,
+    private readonly implicitStandaloneValue: boolean,
   ) {}
 
   readonly precedence = HandlerPrecedence.PRIMARY;
@@ -177,7 +177,7 @@ export class PipeDecoratorHandler
       pure = pureValue;
     }
 
-    let isStandalone = NG_STANDALONE_DEFAULT_VALUE;
+    let isStandalone = this.implicitStandaloneValue;
     if (pipe.has('standalone')) {
       const expr = pipe.get('standalone')!;
       const resolved = this.evaluator.evaluate(expr);

diff --git a/packages/compiler-cli/src/ngtsc/core/src/compiler.ts b/packages/compiler-cli/src/ngtsc/core/src/compiler.ts
@@ -391,6 +391,7 @@ export class NgCompiler {
   private readonly enableLetSyntax: boolean;
   private readonly angularCoreVersion: string | null;
   private readonly enableHmr: boolean;
+  private readonly implicitStandaloneValue: boolean;
 
   /**
    * `NgCompiler` can be reused for multiple compilations (for resource-only changes), and each
@@ -455,14 +456,20 @@ export class NgCompiler {
     readonly usePoisonedData: boolean,
     private livePerfRecorder: ActivePerfRecorder,
   ) {
+    this.angularCoreVersion = options['_angularCoreVersion'] ?? null;
     this.delegatingPerfRecorder = new DelegatingPerfRecorder(this.perfRecorder);
     this.usePoisonedData = usePoisonedData || !!options._compilePoisonedComponents;
     this.enableTemplateTypeChecker =
       enableTemplateTypeChecker || !!options._enableTemplateTypeChecker;
     // TODO(crisbeto): remove this flag and base `enableBlockSyntax` on the `angularCoreVersion`.
     this.enableBlockSyntax = options['_enableBlockSyntax'] ?? true;
     this.enableLetSyntax = options['_enableLetSyntax'] ?? true;
-    this.angularCoreVersion = options['_angularCoreVersion'] ?? null;
+    // Standalone by default is enabled since v19. We need to toggle it here,
+    // because the language service extension may be running with the latest
+    // version of the compiler against an older version of Angular.
+    this.implicitStandaloneValue =
+      this.angularCoreVersion === null ||
+      coreVersionSupportsFeature(this.angularCoreVersion, '>= 19.0.0-0');
     this.enableHmr = !!options['_enableHmr'];
     this.constructionDiagnostics.push(
       ...this.adapter.constructionDiagnostics,
@@ -1494,6 +1501,7 @@ export class NgCompiler {
         this.options.i18nPreserveWhitespaceForLegacyExtraction ?? true,
         !!this.options.strictStandalone,
         this.enableHmr,
+        this.implicitStandaloneValue,
       ),
 
       // TODO(alxhub): understand why the cast here is necessary (something to do with `null`
@@ -1517,6 +1525,7 @@ export class NgCompiler {
         compilationMode,
         jitDeclarationRegistry,
         !!this.options.strictStandalone,
+        this.implicitStandaloneValue,
       ) as Readonly<DecoratorHandler<unknown, unknown, SemanticSymbol | null, unknown>>,
       // Pipe handler must be before injectable handler in list so pipe factories are printed
       // before injectable factories (so injectable factories can delegate to them)
@@ -1532,6 +1541,7 @@ export class NgCompiler {
         compilationMode,
         !!this.options.generateExtraImportsInLocalMode,
         !!this.options.strictStandalone,
+        this.implicitStandaloneValue,
       ),
       new InjectableDecoratorHandler(
         reflector,

diff --git a/packages/compiler-cli/test/ngtsc/ngtsc_spec.ts b/packages/compiler-cli/test/ngtsc/ngtsc_spec.ts
@@ -13,7 +13,7 @@ import {platform} from 'os';
 import ts from 'typescript';
 
 import {ErrorCode, ngErrorCode} from '../../src/ngtsc/diagnostics';
-import {absoluteFrom, NgtscCompilerHost} from '../../src/ngtsc/file_system';
+import {absoluteFrom} from '../../src/ngtsc/file_system';
 import {runInEachFileSystem} from '../../src/ngtsc/file_system/testing';
 import {loadStandardTestFiles} from '../../src/ngtsc/testing';
 import {
@@ -10928,6 +10928,82 @@ runInEachFileSystem((os: string) => {
         expect(env.getContents('/test.js')).toContain(`* @fileoverview Closure comment`);
       });
     });
+
+    describe('standalone by default opt-out', () => {
+      it('should consider declarations as standalone by default', () => {
+        env.write(
+          '/test.ts',
+          `
+            import {Directive, Component, Pipe, NgModule} from '@angular/core';
+
+            @Directive()
+            export class TestDir {}
+
+            @Component({template: ''})
+            export class TestComp {}
+
+            @Pipe({name: 'test'})
+            export class TestPipe {}
+
+            @NgModule({
+              declarations: [TestDir, TestComp, TestPipe]
+            })
+            export class TestModule {}
+          `,
+        );
+
+        const diags = env.driveDiagnostics();
+        expect(diags.length).toBe(3);
+        expect(diags[0].messageText).toContain(
+          'Directive TestDir is standalone, and cannot be declared in an NgModule.',
+        );
+        expect(diags[1].messageText).toContain(
+          'Component TestComp is standalone, and cannot be declared in an NgModule.',
+        );
+        expect(diags[2].messageText).toContain(
+          'Pipe TestPipe is standalone, and cannot be declared in an NgModule.',
+        );
+      });
+
+      it('should disable standalone by default on versions older than 19', () => {
+        env.tsconfig({
+          _angularCoreVersion: '18.2.10',
+        });
+
+        env.write(
+          '/test.ts',
+          `
+            import {Directive, Component, Pipe, NgModule} from '@angular/core';
+
+            @Directive()
+            export class TestDir {}
+
+            @Component({template: ''})
+            export class TestComp {}
+
+            @Pipe({name: 'test'})
+            export class TestPipe {}
+
+            @NgModule({
+              imports: [TestDir, TestComp, TestPipe]
+            })
+            export class TestModule {}
+          `,
+        );
+
+        const diags = env.driveDiagnostics();
+        expect(diags.length).toBe(3);
+        expect(diags[0].messageText).toContain(
+          `The directive 'TestDir' appears in 'imports', but is not standalone`,
+        );
+        expect(diags[1].messageText).toContain(
+          `The component 'TestComp' appears in 'imports', but is not standalone`,
+        );
+        expect(diags[2].messageText).toContain(
+          `The pipe 'TestPipe' appears in 'imports', but is not standalone`,
+        );
+      });
+    });
   });
 
   function expectTokenAtPosition<T extends ts.Node>(