fix: copy loadEsmModule as not present in older angular versions (and…

… internal anyway)

schematics/migrations/2_0_0/index.ts

@@ -1,7 +1,7 @@
 import {Rule, SchematicContext, SchematicsException, Tree} from '@angular-devkit/schematics';
 import {updateWorkspace} from '@schematics/angular/utility/workspace';
-import {loadEsmModule} from '@angular-devkit/architect/node';
 import {Version} from '@angular/core';
+import {loadEsmModule} from '../../../src/loadEsmModule';
 
 function updateNpmScript(tree: Tree, logger: SchematicContext['logger']) {
     const pkgPath = '/package.json';

schematics/ng-add/index.ts

@@ -4,7 +4,7 @@ import {Schema} from './schema';
 import {JsonArray, JsonObject, normalize, Path, relative} from '@angular-devkit/core';
 
 import {Options} from '../../src/options';
-import {loadEsmModule} from '@angular-devkit/architect/node';
+import {loadEsmModule} from '../../src/loadEsmModule';
 import {Version} from '@angular/core';
 
 function getTargetFiles(i18nExtension: JsonObject | undefined): string[] {

src/builder.ts

@@ -8,8 +8,8 @@ import {TranslationFile, TranslationUnit} from './model/translationFileModels';
 import {Merger} from './merger';
 import {Options} from './options';
 import {doCollapseWhitespace} from './stringUtils';
-import {loadEsmModule} from '@angular-devkit/architect/node';
 import {Version} from '@angular/core';
+import {loadEsmModule} from './loadEsmModule';
 
 
 const STATE_INITIAL_XLF_2_0 = 'initial';

src/loadEsmModule.ts

@@ -0,0 +1,26 @@
+/**
+ * This uses a dynamic import to load a module which may be ESM.
+ * CommonJS code can load ESM code via a dynamic import. Unfortunately, TypeScript
+ * will currently, unconditionally downlevel dynamic import into a require call.
+ * require calls cannot load ESM code and will result in a runtime error. To workaround
+ * this, a Function constructor is used to prevent TypeScript from changing the dynamic import.
+ * Once TypeScript provides support for keeping the dynamic import this workaround can
+ * be dropped.
+ * This is only intended to be used with Angular framework packages.
+ *
+ * Copied from https://github.com/angular/angular/blob/e0015d3c456d584242269b0765878d598a550888/packages/core/schematics/utils/load_esm.ts#L11-L35
+ *
+ * @param modulePath The path of the module to load.
+ * @returns A Promise that resolves to the dynamically imported module.
+ */
+export async function loadEsmModule<T>(modulePath: string|URL): Promise<T> {
+    const namespaceObject =
+        (await new Function('modulePath', `return import(modulePath);`)(modulePath));
+
+    // If it is not ESM then the values needed will be stored in the `default` property.
+    if (namespaceObject.default) {
+        return namespaceObject.default;
+    } else {
+        return namespaceObject;
+    }
+}