fix(@schematics/angular): handle aliased or existing environment import (#16377)

Closes: #16226

Author: arturovt

packages/schematics/angular/service-worker/index.ts

@@ -20,7 +20,7 @@ import {
 } from '@angular-devkit/schematics';
 import { NodePackageInstallTask } from '@angular-devkit/schematics/tasks';
 import * as ts from '../third_party/github.com/Microsoft/TypeScript/lib/typescript';
-import { addSymbolToNgModuleMetadata, insertImport, isImported } from '../utility/ast-utils';
+import { addSymbolToNgModuleMetadata, getEnvironmentExportName, insertImport, isImported } from '../utility/ast-utils';
 import { InsertChange } from '../utility/change';
 import { addPackageJsonDependency, getPackageJsonDependency } from '../utility/dependencies';
 import { getAppModulePath } from '../utility/ng-ast-utils';
@@ -71,10 +71,16 @@ function updateAppModule(mainPath: string): Rule {
     // add import for environments
     // import { environment } from '../environments/environment';
     moduleSource = getTsSourceFile(host, modulePath);
-    importModule = 'environment';
+    const environmentExportName = getEnvironmentExportName(moduleSource);
+    // if environemnt import already exists then use the found one
+    // otherwise use the default name
+    importModule = environmentExportName || 'environment';
     // TODO: dynamically find environments relative path
     importPath = '../environments/environment';
-    if (!isImported(moduleSource, importModule, importPath)) {
+
+    if (!environmentExportName) {
+      // if environment import was not found then insert the new one
+      // with default path and default export name
       const change = insertImport(moduleSource, modulePath, importModule, importPath);
       if (change) {
         const recorder = host.beginUpdate(modulePath);
@@ -85,7 +91,7 @@ function updateAppModule(mainPath: string): Rule {
 
     // register SW in app module
     const importText =
-      `ServiceWorkerModule.register('ngsw-worker.js', { enabled: environment.production })`;
+      `ServiceWorkerModule.register('ngsw-worker.js', { enabled: ${importModule}.production })`;
     moduleSource = getTsSourceFile(host, modulePath);
     const metadataChanges = addSymbolToNgModuleMetadata(
       moduleSource, modulePath, 'imports', importText);

packages/schematics/angular/service-worker/index_spec.ts

@@ -10,7 +10,7 @@ import { Schema as ApplicationOptions } from '../application/schema';
 import { Schema as WorkspaceOptions } from '../workspace/schema';
 import { Schema as ServiceWorkerOptions } from './schema';
 
-
+// tslint:disable-next-line:no-big-function
 describe('Service Worker Schematic', () => {
   const schematicRunner = new SchematicTestRunner(
     '@schematics/angular',
@@ -97,6 +97,64 @@ describe('Service Worker Schematic', () => {
     expect(pkgText).toContain(expectedText);
   });
 
+  it('should add the SW import to the NgModule imports with aliased environment', async () => {
+    const moduleContent = `
+      import { BrowserModule } from '@angular/platform-browser';
+      import { NgModule } from '@angular/core';
+
+      import { AppComponent } from './app.component';
+      import { environment as env } from '../environments/environment';
+
+      @NgModule({
+        declarations: [
+          AppComponent
+        ],
+        imports: [
+          BrowserModule
+        ],
+        bootstrap: [AppComponent]
+      })
+      export class AppModule {}
+    `;
+
+    appTree.overwrite('/projects/bar/src/app/app.module.ts', moduleContent);
+
+    const tree = await schematicRunner.runSchematicAsync('service-worker', defaultOptions, appTree)
+      .toPromise();
+    const pkgText = tree.readContent('/projects/bar/src/app/app.module.ts');
+    const expectedText = 'ServiceWorkerModule.register(\'ngsw-worker.js\', { enabled: env.production })';
+    expect(pkgText).toContain(expectedText);
+  });
+
+  it('should add the SW import to the NgModule imports with existing environment', async () => {
+    const moduleContent = `
+      import { BrowserModule } from '@angular/platform-browser';
+      import { NgModule } from '@angular/core';
+
+      import { AppComponent } from './app.component';
+      import { environment } from '../environments/environment';
+
+      @NgModule({
+        declarations: [
+          AppComponent
+        ],
+        imports: [
+          BrowserModule
+        ],
+        bootstrap: [AppComponent]
+      })
+      export class AppModule {}
+    `;
+
+    appTree.overwrite('/projects/bar/src/app/app.module.ts', moduleContent);
+
+    const tree = await schematicRunner.runSchematicAsync('service-worker', defaultOptions, appTree)
+      .toPromise();
+    const pkgText = tree.readContent('/projects/bar/src/app/app.module.ts');
+    const expectedText = 'ServiceWorkerModule.register(\'ngsw-worker.js\', { enabled: environment.production })';
+    expect(pkgText).toContain(expectedText);
+  });
+
   it('should put the ngsw-config.json file in the project root', async () => {
     const tree = await schematicRunner.runSchematicAsync('service-worker', defaultOptions, appTree)
       .toPromise();
@@ -188,5 +246,4 @@ describe('Service Worker Schematic', () => {
     expect(projects.foo.architect.build.configurations.production.ngswConfigPath)
       .toBe('ngsw-config.json');
   });
-
 });

packages/schematics/angular/utility/ast-utils.ts

@@ -574,6 +574,50 @@ export function isImported(source: ts.SourceFile,
   return matchingNodes.length > 0;
 }
 
+/**
+ * This function returns the name of the environment export
+ * whether this export is aliased or not. If the environment file
+ * is not imported, then it will return `null`.
+ */
+export function getEnvironmentExportName(source: ts.SourceFile): string | null {
+  // Initial value is `null` as we don't know yet if the user
+  // has imported `environment` into the root module or not.
+  let environmentExportName: string | null = null;
+
+  const allNodes = getSourceNodes(source);
+
+  allNodes
+    .filter(node => node.kind === ts.SyntaxKind.ImportDeclaration)
+    .filter(
+      (declaration: ts.ImportDeclaration) =>
+        declaration.moduleSpecifier.kind === ts.SyntaxKind.StringLiteral &&
+        declaration.importClause !== undefined,
+    )
+    .map((declaration: ts.ImportDeclaration) =>
+      // If `importClause` property is defined then the first
+      // child will be `NamedImports` object (or `namedBindings`).
+      (declaration.importClause as ts.ImportClause).getChildAt(0),
+    )
+    // Find those `NamedImports` object that contains `environment` keyword
+    // in its text. E.g. `{ environment as env }`.
+    .filter((namedImports: ts.NamedImports) => namedImports.getText().includes('environment'))
+    .forEach((namedImports: ts.NamedImports) => {
+      for (const specifier of namedImports.elements) {
+        // `propertyName` is defined if the specifier
+        // has an aliased import.
+        const name = specifier.propertyName || specifier.name;
+
+        // Find specifier that contains `environment` keyword in its text.
+        // Whether it's `environment` or `environment as env`.
+        if (name.text.includes('environment')) {
+          environmentExportName = specifier.name.text;
+        }
+      }
+    });
+
+  return environmentExportName;
+}
+
 /**
  * Returns the RouterModule declaration from NgModule metadata, if any.
  */