angular · crisbeto · Feb 5, 2023 · Feb 5, 2023
diff --git a/packages/core/schematics/ng-generate/standalone-migration/index.ts b/packages/core/schematics/ng-generate/standalone-migration/index.ts
@@ -38,19 +38,30 @@ export default function(options: Options): Rule {
     const {buildPaths, testPaths} = await getProjectTsConfigPaths(tree);
     const basePath = process.cwd();
     const allPaths = [...buildPaths, ...testPaths];
+    // TS and Schematic use paths in POSIX format even on Windows. This is needed as otherwise
+    // string matching such as `sourceFile.fileName.startsWith(pathToMigrate)` might not work.
+    const pathToMigrate = normalizePath(join(basePath, options.path));
+    let migratedFiles = 0;
 
     if (!allPaths.length) {
       throw new SchematicsException(
           'Could not find any tsconfig file. Cannot run the standalone migration.');
     }
 
     for (const tsconfigPath of allPaths) {
-      standaloneMigration(tree, tsconfigPath, basePath, options);
+      migratedFiles += standaloneMigration(tree, tsconfigPath, basePath, pathToMigrate, options);
+    }
+
+    if (migratedFiles === 0) {
+      throw new SchematicsException(`Could not find any files to migrate under the path ${
+          pathToMigrate}. Cannot run the standalone migration.`);
     }
   };
 }
 
-function standaloneMigration(tree: Tree, tsconfigPath: string, basePath: string, options: Options) {
+function standaloneMigration(
+    tree: Tree, tsconfigPath: string, basePath: string, pathToMigrate: string,
+    options: Options): number {
   if (options.path.startsWith('..')) {
     throw new SchematicsException(
         'Cannot run standalone migration outside of the current project.');
@@ -64,11 +75,6 @@ function standaloneMigration(tree: Tree, tsconfigPath: string, basePath: string,
                   }) as NgtscProgram;
   const printer = ts.createPrinter();
 
-  // TS and Schematic use paths in POSIX format even on Windows.
-  // This is needed as otherwise string matching such as
-  // `sourceFile.fileName.startsWith(pathToMigrate)` will not work correctly.
-  const pathToMigrate = normalizePath(join(basePath, options.path));
-
   if (existsSync(pathToMigrate) && !statSync(pathToMigrate).isDirectory()) {
     throw new SchematicsException(`Migration path ${
         pathToMigrate} has to be a directory. Cannot run the standalone migration.`);
@@ -80,8 +86,7 @@ function standaloneMigration(tree: Tree, tsconfigPath: string, basePath: string,
   });
 
   if (sourceFiles.length === 0) {
-    throw new SchematicsException(`Could not find any files to migrate under the path ${
-        pathToMigrate}. Cannot run the standalone migration.`);
+    return 0;
   }
 
   let pendingChanges: ChangesByFile;
@@ -122,4 +127,6 @@ function standaloneMigration(tree: Tree, tsconfigPath: string, basePath: string,
       tree.delete(relative(basePath, file.fileName));
     }
   }
+
+  return sourceFiles.length;
 }
diff --git a/packages/core/schematics/ng-generate/standalone-migration/to-standalone.ts b/packages/core/schematics/ng-generate/standalone-migration/to-standalone.ts
@@ -310,6 +310,7 @@ function findImportLocation(
     target: Reference<NamedClassDeclaration>, inComponent: Reference<ts.ClassDeclaration>,
     importMode: PotentialImportMode, typeChecker: TemplateTypeChecker): PotentialImport|null {
   const importLocations = typeChecker.getPotentialImportsFor(target, inComponent.node, importMode);
+  let firstSameFileImport: PotentialImport|null = null;
   let firstModuleImport: PotentialImport|null = null;
 
   for (const location of importLocations) {
@@ -318,12 +319,17 @@ function findImportLocation(
     if (location.kind === PotentialImportKind.Standalone) {
       return location;
     }
-    if (location.kind === PotentialImportKind.NgModule && !firstModuleImport) {
+    if (!location.moduleSpecifier && !firstSameFileImport) {
+      firstSameFileImport = location;
+    }
+    if (location.kind === PotentialImportKind.NgModule && !firstModuleImport &&
+        // ɵ is used for some internal Angular modules that we want to skip over.
+        !location.symbolName.startsWith('ɵ')) {
       firstModuleImport = location;
     }
   }
 
-  return firstModuleImport;
+  return firstSameFileImport || firstModuleImport || importLocations[0] || null;
 }
 
 /**

diff --git a/packages/core/schematics/test/standalone_migration_spec.ts b/packages/core/schematics/test/standalone_migration_spec.ts
@@ -970,6 +970,52 @@ describe('standalone migration', () => {
     expect(myCompContent).toContain('imports: [ButtonModule]');
   });
 
+  it('should not reference internal modules', async () => {
+    writeFile('./should-migrate/module.ts', `
+      import {NgModule} from '@angular/core';
+      import {MyComp} from './comp';
+      import {ɵButtonModule} from '../do-not-migrate/button.module';
+
+      @NgModule({imports: [ɵButtonModule], declarations: [MyComp]})
+      export class Mod {}
+    `);
+
+    writeFile('./should-migrate/comp.ts', `
+      import {Component} from '@angular/core';
+
+      @Component({selector: 'my-comp', template: '<my-button>Hello</my-button>'})
+      export class MyComp {}
+    `);
+
+    writeFile('./do-not-migrate/button.module.ts', `
+      import {NgModule, forwardRef} from '@angular/core';
+      import {MyButton} from './button';
+
+      @NgModule({
+        imports: [forwardRef(() => ɵButtonModule)],
+        exports: [forwardRef(() => ɵButtonModule)]
+      })
+      export class ExporterModule {}
+
+      @NgModule({declarations: [MyButton], exports: [MyButton]})
+      export class ɵButtonModule {}
+    `);
+
+    writeFile('./do-not-migrate/button.ts', `
+      import {Component} from '@angular/core';
+
+      @Component({selector: 'my-button', template: '<ng-content></ng-content>'})
+      export class MyButton {}
+    `);
+
+    await runMigration('convert-to-standalone', './should-migrate');
+
+    const myCompContent = tree.readContent('./should-migrate/comp.ts');
+    expect(myCompContent)
+        .toContain(`import { ExporterModule } from '../do-not-migrate/button.module';`);
+    expect(myCompContent).toContain('imports: [ExporterModule]');
+  });
+
   it('should migrate tests with a component declared through TestBed', async () => {
     writeFile('app.spec.ts', `
       import {NgModule, Component} from '@angular/core';