refactor(compiler): rework and expose APIs to be used in schematics (#48730)

Reworks some of the existing compiler APIs to make them easier to use in a schematic and exposes a few new ones to surface information we already had. High-level list of changes:
* `getPotentialImportsFor` now requires a class reference, instead of a `PotentialDirective | PotentialPipe`.
* New `getNgModuleMetadata` method has been added to the type checker.
* New `getPipeMetadata` method has been added to the type checker.
* New `getUsedDirectives` method has been added to the type checker.
* New `getUsedPipes` method has been added to the type checker.
* The `decorator` property was exposed on the `TypeCheckableDirectiveMeta`. The property was already present at runtime, but it wasn't specified on the interface.

PR Close #48730

packages/compiler-cli/private/BUILD.bazel

@@ -14,6 +14,7 @@ ts_library(
         "//packages/compiler-cli/src/ngtsc/perf",
         "//packages/compiler-cli/src/ngtsc/reflection",
         "//packages/compiler-cli/src/ngtsc/sourcemaps",
+        "//packages/compiler-cli/src/ngtsc/typecheck/api",
         "//packages/compiler-cli/src/transformers/downlevel_decorators_transform",
         "@npm//typescript",
     ],

packages/compiler-cli/private/migrations.ts

@@ -15,3 +15,4 @@ export {forwardRefResolver} from '../src/ngtsc/annotations';
 export {Reference} from '../src/ngtsc/imports';
 export {DynamicValue, PartialEvaluator, ResolvedValue, ResolvedValueMap, StaticInterpreter} from '../src/ngtsc/partial_evaluator';
 export {reflectObjectLiteral, TypeScriptReflectionHost} from '../src/ngtsc/reflection';
+export {PotentialImport, PotentialImportKind, PotentialImportMode, TemplateTypeChecker} from '../src/ngtsc/typecheck/api';

packages/compiler-cli/src/ngtsc/typecheck/api/api.ts

@@ -26,6 +26,7 @@ export interface TypeCheckableDirectiveMeta extends DirectiveMeta, DirectiveType
   outputs: ClassPropertyMapping;
   isStandalone: boolean;
   hostDirectives: HostDirectiveMeta[]|null;
+  decorator: ts.Decorator|null;
 }
 
 export type TemplateId = string&{__brand: 'TemplateId'};

packages/compiler-cli/src/ngtsc/typecheck/api/checker.ts

@@ -11,10 +11,13 @@ import ts from 'typescript';
 
 import {AbsoluteFsPath} from '../../../../src/ngtsc/file_system';
 import {ErrorCode} from '../../diagnostics';
+import {Reference} from '../../imports';
+import {NgModuleMeta, PipeMeta} from '../../metadata';
+import {ClassDeclaration} from '../../reflection';
 
 import {FullTemplateMapping, NgTemplateDiagnostic, TypeCheckableDirectiveMeta} from './api';
 import {GlobalCompletion} from './completion';
-import {PotentialDirective, PotentialImport, PotentialPipe} from './scope';
+import {PotentialDirective, PotentialImport, PotentialImportMode, PotentialPipe} from './scope';
 import {ElementSymbol, Symbol, TcbLocation, TemplateSymbol} from './symbols';
 
 /**
@@ -150,8 +153,8 @@ export interface TemplateTypeChecker {
    * In the context of an Angular trait, generate potential imports for a directive.
    */
   getPotentialImportsFor(
-      toImport: PotentialDirective|PotentialPipe,
-      inComponent: ts.ClassDeclaration): ReadonlyArray<PotentialImport>;
+      toImport: Reference<ClassDeclaration>, inComponent: ts.ClassDeclaration,
+      importMode: PotentialImportMode): ReadonlyArray<PotentialImport>;
 
   /**
    * Get the primary decorator for an Angular class (such as @Component). This does not work for
@@ -184,6 +187,26 @@ export interface TemplateTypeChecker {
    */
   getDirectiveMetadata(dir: ts.ClassDeclaration): TypeCheckableDirectiveMeta|null;
 
+  /**
+   * Retrieve the type checking engine's metadata for the given NgModule class, if available.
+   */
+  getNgModuleMetadata(module: ts.ClassDeclaration): NgModuleMeta|null;
+
+  /**
+   * Retrieve the type checking engine's metadata for the given pipe class, if available.
+   */
+  getPipeMetadata(pipe: ts.ClassDeclaration): PipeMeta|null;
+
+  /**
+   * Gets the directives that have been used in a component's template.
+   */
+  getUsedDirectives(component: ts.ClassDeclaration): TypeCheckableDirectiveMeta[]|null;
+
+  /**
+   * Gets the pipes that have been used in a component's template.
+   */
+  getUsedPipes(component: ts.ClassDeclaration): string[]|null;
+
   /**
    * Reset the `TemplateTypeChecker`'s state for the given class, so that it will be recomputed on
    * the next request.

packages/compiler-cli/src/ngtsc/typecheck/api/scope.ts

@@ -89,3 +89,18 @@ export interface PotentialPipe {
    */
   isInScope: boolean;
 }
+
+/**
+ * Possible modes in which to look up a potential import.
+ */
+export enum PotentialImportMode {
+  /** Whether an import is standalone is inferred based on its metadata. */
+  Normal,
+
+  /**
+   * An import is assumed to be standalone and is imported directly. This is useful for migrations
+   * where a declaration wasn't standalone when the program was created, but will become standalone
+   * as a part of the migration.
+   */
+  ForceDirect,
+}

packages/compiler-cli/src/ngtsc/typecheck/src/checker.ts

@@ -6,21 +6,21 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import {AST, CssSelector, DomElementSchemaRegistry, ExternalExpr, LiteralPrimitive, ParseSourceSpan, PropertyRead, SafePropertyRead, TmplAstElement, TmplAstNode, TmplAstReference, TmplAstTemplate, TmplAstTextAttribute, WrappedNodeExpr} from '@angular/compiler';
+import {AST, CssSelector, DomElementSchemaRegistry, ExternalExpr, LiteralPrimitive, ParseSourceSpan, PropertyRead, SafePropertyRead, TmplAstElement, TmplAstNode, TmplAstTemplate, TmplAstTextAttribute, WrappedNodeExpr} from '@angular/compiler';
 import ts from 'typescript';
 
 import {ErrorCode, ngErrorCode} from '../../diagnostics';
-import {absoluteFrom, absoluteFromSourceFile, AbsoluteFsPath, getSourceFileOrError} from '../../file_system';
+import {absoluteFromSourceFile, AbsoluteFsPath, getSourceFileOrError} from '../../file_system';
 import {Reference, ReferenceEmitKind, ReferenceEmitter} from '../../imports';
 import {IncrementalBuild} from '../../incremental/api';
-import {DirectiveMeta, MetadataReader, MetadataReaderWithIndex, MetaKind, NgModuleIndex, PipeMeta} from '../../metadata';
+import {DirectiveMeta, MetadataReader, MetadataReaderWithIndex, MetaKind, NgModuleIndex, NgModuleMeta, PipeMeta} from '../../metadata';
 import {PerfCheckpoint, PerfEvent, PerfPhase, PerfRecorder} from '../../perf';
 import {ProgramDriver, UpdateMode} from '../../program_driver';
 import {ClassDeclaration, DeclarationNode, isNamedClassDeclaration, ReflectionHost} from '../../reflection';
 import {ComponentScopeKind, ComponentScopeReader, TypeCheckScopeRegistry} from '../../scope';
 import {isShim} from '../../shims';
 import {getSourceFileOrNull, isSymbolWithValueDeclaration} from '../../util/src/typescript';
-import {ElementSymbol, FullTemplateMapping, GlobalCompletion, NgTemplateDiagnostic, OptimizeFor, PotentialDirective, PotentialImport, PotentialImportKind, PotentialPipe, ProgramTypeCheckAdapter, Symbol, TcbLocation, TemplateDiagnostic, TemplateId, TemplateSymbol, TemplateTypeChecker, TypeCheckableDirectiveMeta, TypeCheckingConfig} from '../api';
+import {ElementSymbol, FullTemplateMapping, GlobalCompletion, NgTemplateDiagnostic, OptimizeFor, PotentialDirective, PotentialImport, PotentialImportKind, PotentialImportMode, PotentialPipe, ProgramTypeCheckAdapter, Symbol, TcbLocation, TemplateDiagnostic, TemplateId, TemplateSymbol, TemplateTypeChecker, TypeCheckableDirectiveMeta, TypeCheckingConfig} from '../api';
 import {makeTemplateDiagnostic} from '../diagnostics';
 
 import {CompletionEngine} from './completion';
@@ -99,6 +99,14 @@ export class TemplateTypeCheckerImpl implements TemplateTypeChecker {
     return data.template;
   }
 
+  getUsedDirectives(component: ts.ClassDeclaration): TypeCheckableDirectiveMeta[]|null {
+    return this.getLatestComponentState(component).data?.boundTarget.getUsedDirectives() || null;
+  }
+
+  getUsedPipes(component: ts.ClassDeclaration): string[]|null {
+    return this.getLatestComponentState(component).data?.boundTarget.getUsedPipes() || null;
+  }
+
   private getLatestComponentState(component: ts.ClassDeclaration):
       {data: TemplateData|null, tcb: ts.Node|null, tcbPath: AbsoluteFsPath, tcbIsShim: boolean} {
     this.ensureShimForComponent(component);
@@ -598,6 +606,20 @@ export class TemplateTypeCheckerImpl implements TemplateTypeChecker {
     return this.typeCheckScopeRegistry.getTypeCheckDirectiveMetadata(new Reference(dir));
   }
 
+  getNgModuleMetadata(module: ts.ClassDeclaration): NgModuleMeta|null {
+    if (!isNamedClassDeclaration(module)) {
+      return null;
+    }
+    return this.metaReader.getNgModuleMetadata(new Reference(module));
+  }
+
+  getPipeMetadata(pipe: ts.ClassDeclaration): PipeMeta|null {
+    if (!isNamedClassDeclaration(pipe)) {
+      return null;
+    }
+    return this.metaReader.getPipeMetadata(new Reference(pipe));
+  }
+
   getPotentialElementTags(component: ts.ClassDeclaration): Map<string, PotentialDirective|null> {
     if (this.elementTagCache.has(component)) {
       return this.elementTagCache.get(component)!;
@@ -712,18 +734,18 @@ export class TemplateTypeCheckerImpl implements TemplateTypeChecker {
   }
 
   getPotentialImportsFor(
-      toImport: PotentialDirective|PotentialPipe,
-      inContext: ts.ClassDeclaration): ReadonlyArray<PotentialImport> {
+      toImport: Reference<ClassDeclaration>, inContext: ts.ClassDeclaration,
+      importMode: PotentialImportMode): ReadonlyArray<PotentialImport> {
     const imports: PotentialImport[] = [];
 
-    const meta = this.metaReader.getDirectiveMetadata(toImport.ref) ??
-        this.metaReader.getPipeMetadata(toImport.ref);
+    const meta =
+        this.metaReader.getDirectiveMetadata(toImport) ?? this.metaReader.getPipeMetadata(toImport);
     if (meta === null) {
       return imports;
     }
 
-    if (meta.isStandalone) {
-      const emitted = this.emit(PotentialImportKind.Standalone, toImport.ref, inContext);
+    if (meta.isStandalone || importMode === PotentialImportMode.ForceDirect) {
+      const emitted = this.emit(PotentialImportKind.Standalone, toImport, inContext);
       if (emitted !== null) {
         imports.push(emitted);
       }
@@ -732,7 +754,7 @@ export class TemplateTypeCheckerImpl implements TemplateTypeChecker {
     const exportingNgModules = this.ngModuleIndex.getNgModulesExporting(meta.ref.node);
     if (exportingNgModules !== null) {
       for (const exporter of exportingNgModules) {
-        const emittedRef = this.emit(PotentialImportKind.Standalone, exporter, inContext);
+        const emittedRef = this.emit(PotentialImportKind.NgModule, exporter, inContext);
         if (emittedRef !== null) {
           imports.push(emittedRef);
         }

packages/compiler-cli/src/ngtsc/typecheck/testing/index.ts

@@ -663,6 +663,7 @@ function getDirectiveMetaFromDeclaration(
     isStandalone: !!decl.isStandalone,
     baseClass: null,
     animationTriggerNames: null,
+    decorator: null,
     hostDirectives: decl.hostDirectives === undefined ? null : decl.hostDirectives.map(hostDecl => {
       return {
         directive: new Reference(resolveDeclaration(hostDecl.directive)),

packages/compiler-cli/test/ngtsc/ls_typecheck_helpers_spec.ts

@@ -5,6 +5,7 @@
  * 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 {PotentialImportMode} from '@angular/compiler-cli/src/ngtsc/typecheck/api';
 import ts from 'typescript';
 
 import {DiagnosticCategoryLabel} from '../../src/ngtsc/core/api';
@@ -34,7 +35,7 @@ runInEachFileSystem(() => {
       it('for components', () => {
         env.write('test.ts', `
 		 import {Component} from '@angular/core';
- 
+
 		 @Component({
 			 standalone: true,
 			 selector: 'test-cmp',
@@ -52,7 +53,7 @@ runInEachFileSystem(() => {
       it('for pipes', () => {
         env.write('test.ts', `
 		 import {Pipe, PipeTransform} from '@angular/core';
- 
+
 		 @Pipe({name: 'expPipe'})
 		 export class ExpPipe implements PipeTransform {
 			 transform(value: number, exponent = 1): number {
@@ -70,7 +71,7 @@ runInEachFileSystem(() => {
       it('for NgModules', () => {
         env.write('test.ts', `
 			 import {NgModule} from '@angular/core';
- 
+
 			 @NgModule({
 				 declarations: [],
 				 imports: [],
@@ -91,7 +92,7 @@ runInEachFileSystem(() => {
       it('for components', () => {
         env.write('test.ts', `
 			  import {Component, NgModule} from '@angular/core';
-  
+
 			  @NgModule({
 				  declarations: [AppCmp],
 				  imports: [],
@@ -99,7 +100,7 @@ runInEachFileSystem(() => {
 				  bootstrap: [AppCmp]
 			  })
 			  export class AppModule {}
-	
+
 			  @Component({
 				  selector: 'app-cmp',
 				  template: '<div></div>',
@@ -118,7 +119,7 @@ runInEachFileSystem(() => {
       it('for standalone components (which should be null)', () => {
         env.write('test.ts', `
 			  import {Component, NgModule} from '@angular/core';
-  
+
 			  @NgModule({
 				  declarations: [AppCmp],
 				  imports: [],
@@ -126,7 +127,7 @@ runInEachFileSystem(() => {
 				  bootstrap: [AppCmp]
 			  })
 			  export class AppModule {}
-	
+
 			  @Component({
 				  selector: 'app-cmp',
 				  template: '<div></div>',
@@ -146,14 +147,14 @@ runInEachFileSystem(() => {
       it('for pipes', () => {
         env.write('test.ts', `
 			  import {Component, NgModule, Pipe, PipeTransform} from '@angular/core';
-  
+
 			  @NgModule({
 				  declarations: [ExpPipe],
 				  imports: [],
 				  providers: [],
 			  })
 			  export class PipeModule {}
-	
+
 			  @Pipe({name: 'expPipe'})
 			  export class ExpPipe implements PipeTransform {
 				  transform(value: number, exponent = 1): number {
@@ -175,7 +176,7 @@ runInEachFileSystem(() => {
       it('which are out of scope', () => {
         env.write('one.ts', `
 		   import {Component} from '@angular/core';
-   
+
 		   @Component({
 			   standalone: true,
 			   selector: 'one-cmp',
@@ -186,7 +187,7 @@ runInEachFileSystem(() => {
 
         env.write('two.ts', `
 		   import {Component} from '@angular/core';
-   
+
 		   @Component({
 			   standalone: true,
 			   selector: 'two-cmp',
@@ -206,7 +207,7 @@ runInEachFileSystem(() => {
       it('which are out of scope', () => {
         env.write('one.ts', `
 			 import {Pipe} from '@angular/core';
-	 
+
 			 @Pipe({
 				name: 'foo-pipe',
 				standalone: true,
@@ -217,7 +218,7 @@ runInEachFileSystem(() => {
 
         env.write('two.ts', `
 			 import {Component} from '@angular/core';
-	 
+
 			 @Component({
 				 standalone: true,
 				 selector: 'two-cmp',
@@ -237,7 +238,7 @@ runInEachFileSystem(() => {
       it('for out of scope standalone components', () => {
         env.write('one.ts', `
 			 import {Component} from '@angular/core';
-	 
+
 			 @Component({
 				 standalone: true,
 				 selector: 'one-cmp',
@@ -248,7 +249,7 @@ runInEachFileSystem(() => {
 
         env.write('two.ts', `
 			 import {Component} from '@angular/core';
-	 
+
 			 @Component({
 				 standalone: true,
 				 selector: 'two-cmp',
@@ -263,7 +264,8 @@ runInEachFileSystem(() => {
 
         const TwoCmpDir = checker.getPotentialTemplateDirectives(OneCmpClass)
                               .filter(d => d.selector === 'two-cmp')[0];
-        const imports = checker.getPotentialImportsFor(TwoCmpDir, OneCmpClass);
+        const imports =
+            checker.getPotentialImportsFor(TwoCmpDir.ref, OneCmpClass, PotentialImportMode.Normal);
 
         expect(imports.length).toBe(1);
         expect(imports[0].moduleSpecifier).toBe('./two');
@@ -273,7 +275,7 @@ runInEachFileSystem(() => {
       it('for out of scope ngModules', () => {
         env.write('one.ts', `
 			 import {Component} from '@angular/core';
-	 
+
 			 @Component({
 				 standalone: true,
 				 selector: 'one-cmp',
@@ -284,7 +286,7 @@ runInEachFileSystem(() => {
 
         env.write('two.ts', `
 			 import {Component} from '@angular/core';
-	 
+
 			 @Component({
 				 selector: 'two-cmp',
 				 template: '<div></div>',
@@ -296,7 +298,7 @@ runInEachFileSystem(() => {
 			import { NgModule } from '@angular/core';
 			import { CommonModule } from '@angular/common';
 			import { TwoCmp } from './two';
-			
+
 			@NgModule({
 			declarations: [
 				TwoCmp
@@ -318,7 +320,8 @@ runInEachFileSystem(() => {
 
         const TwoNgMod = checker.getPotentialTemplateDirectives(OneCmpClass)
                              .filter(d => d.selector === 'two-cmp')[0];
-        const imports = checker.getPotentialImportsFor(TwoNgMod, OneCmpClass);
+        const imports =
+            checker.getPotentialImportsFor(TwoNgMod.ref, OneCmpClass, PotentialImportMode.Normal);
 
         expect(imports.length).toBe(1);
         expect(imports[0].moduleSpecifier).toBe('./twomod');

packages/compiler/src/render3/view/t2_binder.ts

@@ -331,8 +331,6 @@ class DirectiveBinder<DirectiveT extends DirectiveMeta> implements Visitor {
 class TemplateBinder extends RecursiveAstVisitor implements Visitor {
   private visitNode: (node: Node) => void;
 
-  private pipesUsed: string[] = [];
-
   private constructor(
       private bindings: Map<AST, Reference|Variable>,
       private symbols: Map<Reference|Variable, Template>, private usedPipes: Set<string>,

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

@@ -8,7 +8,7 @@
 
 import {ASTWithName} from '@angular/compiler';
 import {ErrorCode as NgCompilerErrorCode, ngErrorCode} from '@angular/compiler-cli/src/ngtsc/diagnostics/index';
-import {PotentialDirective, PotentialPipe} from '@angular/compiler-cli/src/ngtsc/typecheck/api';
+import {PotentialDirective, PotentialImportMode, PotentialPipe} from '@angular/compiler-cli/src/ngtsc/typecheck/api';
 import * as t from '@angular/compiler/src/render3/r3_ast';  // t for template AST
 import ts from 'typescript';
 
@@ -72,7 +72,8 @@ function getCodeActions(
   }
   for (const currMatch of matches.values()) {
     const currMatchSymbol = currMatch.tsSymbol.valueDeclaration!;
-    const potentialImports = checker.getPotentialImportsFor(currMatch, importOn);
+    const potentialImports =
+        checker.getPotentialImportsFor(currMatch.ref, importOn, PotentialImportMode.Normal);
     for (let potentialImport of potentialImports) {
       let [fileImportChanges, importName] = updateImportsForTypescriptFile(
           tsChecker, importOn.getSourceFile(), potentialImport, currMatchSymbol.getSourceFile());