cli_support.ts

/**
 * @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 * as path from './path';

/**
 * asserts that the given fileName is an absolute path.
 *
 * The TypeScript API works in absolute paths, so we must be careful to resolve
 * paths before handing them over to TypeScript.
 */
export function assertAbsolute(fileName: string) {
  if (!path.isAbsolute(fileName)) {
    throw new Error(`expected ${JSON.stringify(fileName)} to be absolute`);
  }
}

/**
 * Takes a context (ts.SourceFile.fileName of the current file) and the import URL of an ES6
 * import and generates a googmodule module name for the imported module.
 */
export function pathToModuleName(
  rootModulePath: string,
  context: string,
  fileName: string,
): string {
  fileName = fileName.replace(/(\.d)?\.[tj]s$/, '');

  if (fileName[0] === '.') {
    // './foo' or '../foo'.
    // Resolve the path against the dirname of the current module.
    fileName = path.join(path.dirname(context), fileName);
  }

  // TODO(evanm): various tests assume they can import relative paths like
  // 'foo/bar' and have them interpreted as root-relative; preserve that here.
  // Fix this by removing the next line.
  if (!path.isAbsolute(fileName)) {
    fileName = path.join(rootModulePath, fileName);
  }

  // TODO(evanm): various tests assume they can pass in a 'fileName' like
  // 'goog:foo.bar' and have this function do something reasonable.

  // For correctness, the above must have produced an absolute path.
  // assertAbsolute(fileName);

  if (rootModulePath) {
    fileName = path.relative(rootModulePath, fileName);
  }

  // Replace characters not supported by goog.module.
  const moduleName = fileName
    .replace(/\/|\\/g, '.')
    .replace(/^[^a-zA-Z_$]/, '_')
    .replace(/[^a-zA-Z0-9._$]/g, '_');

  return moduleName;
}