feat(ivy): ngcc - implement CommonJsRenderingFormatter (#30200)

PR Close #30200

packages/compiler-cli/ngcc/src/rendering/commonjs_rendering_formatter.ts

@@ -0,0 +1,70 @@
+/**
+ * @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, relative} from 'canonical-path';
+import * as ts from 'typescript';
+import MagicString from 'magic-string';
+import {Import, ImportManager} from '../../../src/ngtsc/translator';
+import {ExportInfo} from '../analysis/private_declarations_analyzer';
+import {isRequireCall} from '../host/commonjs_host';
+import {NgccReflectionHost} from '../host/ngcc_host';
+import {Esm5RenderingFormatter} from './esm5_rendering_formatter';
+import {stripExtension} from './utils';
+
+/**
+ * A RenderingFormatter that works with CommonJS files, instead of `import` and `export` statements
+ * the module is an IIFE with a factory function call with dependencies, which are defined in a
+ * wrapper function for AMD, CommonJS and global module formats.
+ */
+export class CommonJsRenderingFormatter extends Esm5RenderingFormatter {
+  constructor(protected commonJsHost: NgccReflectionHost, isCore: boolean) {
+    super(commonJsHost, isCore);
+  }
+
+  /**
+   *  Add the imports below any in situ imports as `require` calls.
+   */
+  addImports(output: MagicString, imports: Import[], file: ts.SourceFile): void {
+    const insertionPoint = this.findEndOfImports(file);
+    const renderedImports =
+        imports.map(i => `var ${i.qualifier} = require('${i.specifier}');\n`).join('');
+    output.appendLeft(insertionPoint, renderedImports);
+  }
+
+  /**
+   * Add the exports to the bottom of the file.
+   */
+  addExports(
+      output: MagicString, entryPointBasePath: string, exports: ExportInfo[],
+      importManager: ImportManager, file: ts.SourceFile): void {
+    exports.forEach(e => {
+      const basePath = stripExtension(e.from);
+      const relativePath = './' + relative(dirname(entryPointBasePath), basePath);
+      const namedImport = entryPointBasePath !== basePath ?
+          importManager.generateNamedImport(relativePath, e.identifier) :
+          {symbol: e.identifier, moduleImport: null};
+      const importNamespace = namedImport.moduleImport ? `${namedImport.moduleImport}.` : '';
+      const exportStr = `\nexports.${e.identifier} = ${importNamespace}${namedImport.symbol};`;
+      output.append(exportStr);
+    });
+  }
+
+  protected findEndOfImports(sf: ts.SourceFile): number {
+    for (const statement of sf.statements) {
+      if (ts.isExpressionStatement(statement) && isRequireCall(statement.expression)) {
+        continue;
+      }
+      const declarations = ts.isVariableStatement(statement) ?
+          Array.from(statement.declarationList.declarations) :
+          [];
+      if (declarations.some(d => !d.initializer || !isRequireCall(d.initializer))) {
+        return statement.getStart();
+      }
+    }
+    return 0;
+  }
+}