refactor(compiler-cli): update ImportGenerator abstraction for new …

…manager (#54983)

`ImportGenerator` is the abstraction used by the translator functions to
insert imports for `ExternalExpr` in an AST-agnostic way.

This was built specifically for the linker which does not use any of the
complex import managers- but rather re-uses `ngImport` or uses
`ngImport.Bla`.

This commit also switches the linker AST-agnostic generator to follow
the new signatures. This was rather trivial.

PR Close #54983

packages/compiler-cli/linker/src/file_linker/emit_scopes/emit_scope.ts

@@ -36,15 +36,15 @@ export class EmitScope<TStatement, TExpression> {
    */
   translateDefinition(definition: LinkedDefinition): TExpression {
     const expression = this.translator.translateExpression(
-        definition.expression, new LinkerImportGenerator(this.ngImport));
+        definition.expression, new LinkerImportGenerator(this.factory, this.ngImport));
 
     if (definition.statements.length > 0) {
       // Definition statements must be emitted "after" the declaration for which the definition is
       // being emitted. However, the linker only transforms individual declaration calls, and can't
       // insert statements after definitions. To work around this, the linker transforms the
       // definition into an IIFE which executes the definition statements before returning the
       // definition expression.
-      const importGenerator = new LinkerImportGenerator(this.ngImport);
+      const importGenerator = new LinkerImportGenerator(this.factory, this.ngImport);
       return this.wrapInIifeWithStatements(
           expression,
           definition.statements.map(
@@ -59,7 +59,7 @@ export class EmitScope<TStatement, TExpression> {
    * Return any constant statements that are shared between all uses of this `EmitScope`.
    */
   getConstantStatements(): TStatement[] {
-    const importGenerator = new LinkerImportGenerator(this.ngImport);
+    const importGenerator = new LinkerImportGenerator(this.factory, this.ngImport);
     return this.constantPool.statements.map(
         statement => this.translator.translateStatement(statement, importGenerator));
   }

packages/compiler-cli/linker/src/file_linker/translator.ts

@@ -20,21 +20,23 @@ export class Translator<TStatement, TExpression> {
    * Translate the given output AST in the context of an expression.
    */
   translateExpression(
-      expression: o.Expression, imports: ImportGenerator<TExpression>,
+      expression: o.Expression, imports: ImportGenerator<null, TExpression>,
       options: TranslatorOptions<TExpression> = {}): TExpression {
     return expression.visitExpression(
-        new ExpressionTranslatorVisitor<TStatement, TExpression>(this.factory, imports, options),
+        new ExpressionTranslatorVisitor<null, TStatement, TExpression>(
+            this.factory, imports, null, options),
         new Context(false));
   }
 
   /**
    * Translate the given output AST in the context of a statement.
    */
   translateStatement(
-      statement: o.Statement, imports: ImportGenerator<TExpression>,
+      statement: o.Statement, imports: ImportGenerator<null, TExpression>,
       options: TranslatorOptions<TExpression> = {}): TStatement {
     return statement.visitStatement(
-        new ExpressionTranslatorVisitor<TStatement, TExpression>(this.factory, imports, options),
+        new ExpressionTranslatorVisitor<null, TStatement, TExpression>(
+            this.factory, imports, null, options),
         new Context(true));
   }
 }

packages/compiler-cli/linker/src/linker_import_generator.ts

@@ -5,7 +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 {ImportGenerator, NamedImport} from '../../src/ngtsc/translator';
+import {AstFactory, ImportGenerator, ImportRequest} from '../../src/ngtsc/translator';
 
 import {FatalLinkerError} from './fatal_linker_error';
 
@@ -17,17 +17,19 @@ import {FatalLinkerError} from './fatal_linker_error';
  * must be achieved by property access on an `ng` namespace identifier, which is passed in via the
  * constructor.
  */
-export class LinkerImportGenerator<TExpression> implements ImportGenerator<TExpression> {
-  constructor(private ngImport: TExpression) {}
-
-  generateNamespaceImport(moduleName: string): TExpression {
-    this.assertModuleName(moduleName);
-    return this.ngImport;
+export class LinkerImportGenerator<TStatement, TExpression> implements
+    ImportGenerator<null, TExpression> {
+  constructor(private factory: AstFactory<TStatement, TExpression>, private ngImport: TExpression) {
   }
 
-  generateNamedImport(moduleName: string, originalSymbol: string): NamedImport<TExpression> {
-    this.assertModuleName(moduleName);
-    return {moduleImport: this.ngImport, symbol: originalSymbol};
+  addImport(request: ImportRequest<null>): TExpression {
+    this.assertModuleName(request.exportModuleSpecifier);
+
+    if (request.exportSymbolName === null) {
+      return this.ngImport;
+    }
+
+    return this.factory.createPropertyAccess(this.ngImport, request.exportSymbolName);
   }
 
   private assertModuleName(moduleName: string): void {

packages/compiler-cli/linker/test/file_linker/translator_spec.ts

@@ -6,21 +6,30 @@
  * found in the LICENSE file at https://angular.io/license
  */
 import * as o from '@angular/compiler';
-import {ImportGenerator, NamedImport, TypeScriptAstFactory} from '@angular/compiler-cli/src/ngtsc/translator';
+import {TypeScriptAstFactory} from '@angular/compiler-cli/src/ngtsc/translator';
 import ts from 'typescript';
 
 import {Translator} from '../../src/file_linker/translator';
+import {LinkerImportGenerator} from '../../src/linker_import_generator';
+
 import {generate} from './helpers';
 
+const ngImport = ts.factory.createIdentifier('ngImport');
+
 describe('Translator', () => {
   let factory: TypeScriptAstFactory;
-  beforeEach(() => factory = new TypeScriptAstFactory(/* annotateForClosureCompiler */ false));
+  let importGenerator: LinkerImportGenerator<ts.Statement, ts.Expression>;
+
+  beforeEach(() => {
+    factory = new TypeScriptAstFactory(/* annotateForClosureCompiler */ false);
+    importGenerator = new LinkerImportGenerator<ts.Statement, ts.Expression>(factory, ngImport);
+  });
 
   describe('translateExpression()', () => {
     it('should generate expression specific output', () => {
       const translator = new Translator<ts.Statement, ts.Expression>(factory);
       const outputAst = new o.WriteVarExpr('foo', new o.LiteralExpr(42));
-      const translated = translator.translateExpression(outputAst, new MockImportGenerator());
+      const translated = translator.translateExpression(outputAst, importGenerator);
       expect(generate(translated)).toEqual('(foo = 42)');
     });
   });
@@ -29,19 +38,8 @@ describe('Translator', () => {
     it('should generate statement specific output', () => {
       const translator = new Translator<ts.Statement, ts.Expression>(factory);
       const outputAst = new o.ExpressionStatement(new o.WriteVarExpr('foo', new o.LiteralExpr(42)));
-      const translated = translator.translateStatement(outputAst, new MockImportGenerator());
+      const translated = translator.translateStatement(outputAst, importGenerator);
       expect(generate(translated)).toEqual('foo = 42;');
     });
   });
-  class MockImportGenerator implements ImportGenerator<ts.Expression> {
-    generateNamespaceImport(moduleName: string): ts.Expression {
-      return factory.createLiteral(moduleName);
-    }
-    generateNamedImport(moduleName: string, originalSymbol: string): NamedImport<ts.Expression> {
-      return {
-        moduleImport: factory.createLiteral(moduleName),
-        symbol: originalSymbol,
-      };
-    }
-  }
 });

packages/compiler-cli/linker/test/linker_import_generator_spec.ts

@@ -5,37 +5,62 @@
  * 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 ts from 'typescript';
+
+import {TypeScriptAstFactory} from '../../src/ngtsc/translator';
 import {LinkerImportGenerator} from '../src/linker_import_generator';
 
-const ngImport = {
-  ngImport: true
-};
+const ngImport = ts.factory.createIdentifier('ngImport');
 
 describe('LinkerImportGenerator<TExpression>', () => {
   describe('generateNamespaceImport()', () => {
     it('should error if the import is not `@angular/core`', () => {
-      const generator = new LinkerImportGenerator(ngImport);
-      expect(() => generator.generateNamespaceImport('other/import'))
+      const generator = new LinkerImportGenerator<ts.Statement, ts.Expression>(
+          new TypeScriptAstFactory(false), ngImport);
+
+      expect(
+          () => generator.addImport(
+              {exportModuleSpecifier: 'other/import', exportSymbolName: null, requestedFile: null}))
           .toThrowError(`Unable to import from anything other than '@angular/core'`);
     });
 
     it('should return the ngImport expression for `@angular/core`', () => {
-      const generator = new LinkerImportGenerator(ngImport);
-      expect(generator.generateNamespaceImport('@angular/core')).toBe(ngImport);
+      const generator = new LinkerImportGenerator<ts.Statement, ts.Expression>(
+          new TypeScriptAstFactory(false), ngImport);
+
+      expect(generator.addImport({
+        exportModuleSpecifier: '@angular/core',
+        exportSymbolName: null,
+        requestedFile: null
+      })).toBe(ngImport);
     });
   });
 
   describe('generateNamedImport()', () => {
     it('should error if the import is not `@angular/core`', () => {
-      const generator = new LinkerImportGenerator(ngImport);
-      expect(() => generator.generateNamedImport('other/import', 'someSymbol'))
-          .toThrowError(`Unable to import from anything other than '@angular/core'`);
+      const generator = new LinkerImportGenerator<ts.Statement, ts.Expression>(
+          new TypeScriptAstFactory(false), ngImport);
+
+      expect(() => generator.addImport({
+        exportModuleSpecifier: 'other/import',
+        exportSymbolName: 'someSymbol',
+        requestedFile: null,
+      })).toThrowError(`Unable to import from anything other than '@angular/core'`);
     });
 
     it('should return a `NamedImport` object containing the ngImport expression', () => {
-      const generator = new LinkerImportGenerator(ngImport);
-      expect(generator.generateNamedImport('@angular/core', 'someSymbol'))
-          .toEqual({moduleImport: ngImport, symbol: 'someSymbol'});
+      const generator = new LinkerImportGenerator<ts.Statement, ts.Expression>(
+          new TypeScriptAstFactory(false), ngImport);
+
+      const result = generator.addImport({
+        exportModuleSpecifier: '@angular/core',
+        exportSymbolName: 'someSymbol',
+        requestedFile: null,
+      });
+
+      expect(ts.isPropertyAccessExpression(result)).toBe(true);
+      expect((result as ts.PropertyAccessExpression).name.text).toBe('someSymbol');
+      expect((result as ts.PropertyAccessExpression).expression).toBe(ngImport);
     });
   });
 });

packages/compiler-cli/src/ngtsc/annotations/common/test/metadata_spec.ts

@@ -135,7 +135,7 @@ runInEachFileSystem(() => {
     const sf = getSourceFileOrError(program, _('/index.ts'));
     const im = new ImportManager(new NoopImportRewriter(), 'i');
     const stmt = compileClassMetadata(call).toStmt();
-    const tsStatement = translateStatement(stmt, im);
+    const tsStatement = translateStatement(sf, stmt, im);
     const res = ts.createPrinter().printNode(ts.EmitHint.Unspecified, tsStatement, sf);
     return res.replace(/\s+/g, ' ');
   }

packages/compiler-cli/src/ngtsc/transform/src/transform.ts

@@ -118,14 +118,19 @@ class IvyTransformationVisitor extends Visitor {
     const statements: ts.Statement[] = [];
     const members = [...node.members];
 
+    // Note: Class may be already transformed by e.g. Tsickle and
+    // not have a direct reference to the source file.
+    const sourceFile = ts.getOriginalNode(node).getSourceFile();
+
     for (const field of this.classCompilationMap.get(node)!) {
       // Type-only member.
       if (field.initializer === null) {
         continue;
       }
 
       // Translate the initializer for the field into TS nodes.
-      const exprNode = translateExpression(field.initializer, this.importManager, translateOptions);
+      const exprNode =
+          translateExpression(sourceFile, field.initializer, this.importManager, translateOptions);
 
       // Create a static property declaration for the new field.
       const property = ts.factory.createPropertyDeclaration(
@@ -142,7 +147,8 @@ class IvyTransformationVisitor extends Visitor {
             /* hasTrailingNewLine */ false);
       }
 
-      field.statements.map(stmt => translateStatement(stmt, this.importManager, translateOptions))
+      field.statements
+          .map(stmt => translateStatement(sourceFile, stmt, this.importManager, translateOptions))
           .forEach(stmt => statements.push(stmt));
 
       members.push(property);
@@ -313,7 +319,7 @@ function transformIvySourceFile(
   // to the ImportManager.
   const downlevelTranslatedCode = getLocalizeCompileTarget(context) < ts.ScriptTarget.ES2015;
   const constants =
-      constantPool.statements.map(stmt => translateStatement(stmt, importManager, {
+      constantPool.statements.map(stmt => translateStatement(file, stmt, importManager, {
                                     recordWrappedNode,
                                     downlevelTaggedTemplates: downlevelTranslatedCode,
                                     downlevelVariableDeclarations: downlevelTranslatedCode,

packages/compiler-cli/src/ngtsc/translator/src/api/import_generator.ts

@@ -6,17 +6,6 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-/**
- * The symbol name and import namespace of an imported symbol,
- * which has been registered through the ImportGenerator.
- */
-export interface NamedImport<TExpression> {
-  /** The import namespace containing this imported symbol. */
-  moduleImport: TExpression|null;
-  /** The (possibly rewritten) name of the imported symbol. */
-  symbol: string;
-}
-
 /**
  * A request to import a given symbol from the given module.
  */
@@ -49,7 +38,6 @@ export interface ImportRequest<TFile> {
  * Implementations of these methods return a specific identifier that corresponds to the imported
  * module.
  */
-export interface ImportGenerator<TExpression> {
-  generateNamespaceImport(moduleName: string): TExpression;
-  generateNamedImport(moduleName: string, originalSymbol: string): NamedImport<TExpression>;
+export interface ImportGenerator<TFile, TExpression> {
+  addImport(request: ImportRequest<TFile>): TExpression;
 }

packages/compiler-cli/src/ngtsc/translator/src/translator.ts

@@ -46,15 +46,16 @@ export interface TranslatorOptions<TExpression> {
   annotateForClosureCompiler?: boolean;
 }
 
-export class ExpressionTranslatorVisitor<TStatement, TExpression> implements o.ExpressionVisitor,
-                                                                             o.StatementVisitor {
+export class ExpressionTranslatorVisitor<TFile, TStatement, TExpression> implements
+    o.ExpressionVisitor, o.StatementVisitor {
   private downlevelTaggedTemplates: boolean;
   private downlevelVariableDeclarations: boolean;
   private recordWrappedNode: RecordWrappedNodeFn<TExpression>;
 
   constructor(
       private factory: AstFactory<TStatement, TExpression>,
-      private imports: ImportGenerator<TExpression>, options: TranslatorOptions<TExpression>) {
+      private imports: ImportGenerator<TFile, TExpression>, private contextFile: TFile,
+      options: TranslatorOptions<TExpression>) {
     this.downlevelTaggedTemplates = options.downlevelTaggedTemplates === true;
     this.downlevelVariableDeclarations = options.downlevelVariableDeclarations === true;
     this.recordWrappedNode = options.recordWrappedNode || (() => {});
@@ -210,11 +211,11 @@ export class ExpressionTranslatorVisitor<TStatement, TExpression> implements o.E
   private createES5TaggedTemplateFunctionCall(
       tagHandler: TExpression, {elements, expressions}: TemplateLiteral<TExpression>): TExpression {
     // Ensure that the `__makeTemplateObject()` helper has been imported.
-    const {moduleImport, symbol} =
-        this.imports.generateNamedImport('tslib', '__makeTemplateObject');
-    const __makeTemplateObjectHelper = (moduleImport === null) ?
-        this.factory.createIdentifier(symbol) :
-        this.factory.createPropertyAccess(moduleImport, symbol);
+    const __makeTemplateObjectHelper = this.imports.addImport({
+      exportModuleSpecifier: 'tslib',
+      exportSymbolName: '__makeTemplateObject',
+      requestedFile: this.contextFile,
+    });
 
     // Collect up the cooked and raw strings into two separate arrays.
     const cooked: TExpression[] = [];
@@ -244,20 +245,21 @@ export class ExpressionTranslatorVisitor<TStatement, TExpression> implements o.E
       if (ast.value.moduleName === null) {
         throw new Error('Invalid import without name nor moduleName');
       }
-      return this.imports.generateNamespaceImport(ast.value.moduleName);
+      return this.imports.addImport({
+        exportModuleSpecifier: ast.value.moduleName,
+        exportSymbolName: null,
+        requestedFile: this.contextFile,
+      });
     }
     // If a moduleName is specified, this is a normal import. If there's no module name, it's a
     // reference to a global/ambient symbol.
     if (ast.value.moduleName !== null) {
       // This is a normal import. Find the imported module.
-      const {moduleImport, symbol} =
-          this.imports.generateNamedImport(ast.value.moduleName, ast.value.name);
-      if (moduleImport === null) {
-        // The symbol was ambient after all.
-        return this.factory.createIdentifier(symbol);
-      } else {
-        return this.factory.createPropertyAccess(moduleImport, symbol);
-      }
+      return this.imports.addImport({
+        exportModuleSpecifier: ast.value.moduleName,
+        exportSymbolName: ast.value.name,
+        requestedFile: this.contextFile,
+      });
     } else {
       // The symbol is ambient, so just reference it.
       return this.factory.createIdentifier(ast.value.name);