feat(ivy): ngcc - support creating a new copy of the entry-point format (#29092)

This commit adds a `NewEntryPointFileWriter` that will be used in
webpack integration. Instead of overwriting files in-place, this `FileWriter`
will make a copy of the TS program files and write the transformed files
there. It also updates the package.json with new properties that can be
used to access the new entry-point format.

FW-1121

PR Close #29092

packages/compiler-cli/ngcc/src/writing/new_entry_point_file_writer.ts

@@ -0,0 +1,72 @@
+
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * 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 {dirname, join, relative} from 'canonical-path';
+import {writeFileSync} from 'fs';
+import {cp, mkdir} from 'shelljs';
+
+import {AbsoluteFsPath} from '../../../src/ngtsc/path';
+import {isDtsPath} from '../../../src/ngtsc/util/src/typescript';
+import {EntryPoint, EntryPointJsonProperty} from '../packages/entry_point';
+import {EntryPointBundle} from '../packages/entry_point_bundle';
+import {FileInfo} from '../rendering/renderer';
+
+import {InPlaceFileWriter} from './in_place_file_writer';
+
+const NGCC_DIRECTORY = '__ivy_ngcc__';
+
+/**
+ * This FileWriter creates a copy of the original entry-point, then writes the transformed
+ * files onto the files in this copy, and finally updates the package.json with a new
+ * entry-point format property that points to this new entry-point.
+ *
+ * If there are transformed typings files in this bundle, they are updated in-place (see the
+ * `InPlaceFileWriter`).
+ */
+export class NewEntryPointFileWriter extends InPlaceFileWriter {
+  writeBundle(entryPoint: EntryPoint, bundle: EntryPointBundle, transformedFiles: FileInfo[]) {
+    // The new folder is at the root of the overall package
+    const relativeEntryPointPath = relative(entryPoint.package, entryPoint.path);
+    const relativeNewDir = join(NGCC_DIRECTORY, relativeEntryPointPath);
+    const newDir = AbsoluteFsPath.fromUnchecked(join(entryPoint.package, relativeNewDir));
+    this.copyBundle(bundle, entryPoint.path, newDir);
+    transformedFiles.forEach(file => this.writeFile(file, entryPoint.path, newDir));
+    this.updatePackageJson(entryPoint, bundle.formatProperty, newDir);
+  }
+
+  protected copyBundle(
+      bundle: EntryPointBundle, entryPointPath: AbsoluteFsPath, newDir: AbsoluteFsPath) {
+    bundle.src.program.getSourceFiles().forEach(sourceFile => {
+      const relativePath = relative(entryPointPath, sourceFile.fileName);
+      const newFilePath = join(newDir, relativePath);
+      mkdir('-p', dirname(newFilePath));
+      cp(sourceFile.fileName, newFilePath);
+    });
+  }
+
+  protected writeFile(file: FileInfo, entryPointPath: AbsoluteFsPath, newDir: AbsoluteFsPath):
+      void {
+    if (isDtsPath(file.path)) {
+      super.writeFileAndBackup(file);
+    } else {
+      const relativePath = relative(entryPointPath, file.path);
+      const newFilePath = join(newDir, relativePath);
+      mkdir('-p', dirname(newFilePath));
+      writeFileSync(newFilePath, file.contents, 'utf8');
+    }
+  }
+
+  protected updatePackageJson(
+      entryPoint: EntryPoint, formatProperty: EntryPointJsonProperty, newDir: AbsoluteFsPath) {
+    const bundlePath = entryPoint.packageJson[formatProperty] !;
+    const newBundlePath = relative(entryPoint.path, join(newDir, bundlePath));
+    (entryPoint.packageJson as any)[formatProperty + '_ivy_ngcc'] = newBundlePath;
+    writeFileSync(join(entryPoint.path, 'package.json'), JSON.stringify(entryPoint.packageJson));
+  }
+}