text: #!/usr/bin/env node
  /**
   * Copyright 2019 Google Inc. All rights reserved.
   * Modifications copyright (c) Microsoft Corporation.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  const ts = require('typescript');
  const path = require('path');
  const Source = require('./doclint/Source');
  
  async function checkDeps() {
    const root = path.normalize(path.join(__dirname, '..'));
    const src = path.normalize(path.join(__dirname, '..', 'src'));
    const sources = await Source.readdir(src);
    const program = ts.createProgram({
      options: {
        allowJs: true,
        target: ts.ScriptTarget.ESNext,
        strict: true,
      },
      rootNames: sources.map(source => source.filePath()),
    });
    const sourceFiles = program.getSourceFiles();
    const errors = [];
    sourceFiles.filter(x => !x.fileName.includes('node_modules')).map(x => visit(x, x.fileName));
    for (const error of errors)
      console.log(error);
    if (errors.length) {
      console.log(`--------------------------------------------------------`);
      console.log(`Changing the project structure or adding new components?`);
      console.log(`Update DEPS in //${path.relative(root, __filename)}.`);
      console.log(`--------------------------------------------------------`);
    }
    process.exit(errors.length ? 1 : 0);
  
    function visit(node, fileName) {
      if (ts.isImportDeclaration(node) && ts.isStringLiteral(node.moduleSpecifier)) {
        const importName = node.moduleSpecifier.text;
        const importPath = path.resolve(path.dirname(fileName), importName) + '.ts';
        if (!allowImport(fileName, importPath))
          errors.push(`Disallowed import from ${path.relative(root, fileName)} to ${path.relative(root, importPath)}`);
      }
      ts.forEachChild(node, x => visit(x, fileName));
    }
  
    function allowImport(from, to) {
      from = from.substring(from.indexOf('src' + path.sep)).replace(/\\/g, '/');
      to = to.substring(to.indexOf('src' + path.sep)).replace(/\\/g, '/');
      const fromDirectory = from.substring(0, from.lastIndexOf('/') + 1);
      const toDirectory = to.substring(0, to.lastIndexOf('/') + 1);
      if (fromDirectory === toDirectory)
        return true;
  
      while (!DEPS[from]) {
        if (from.endsWith('/'))
          from = from.substring(0, from.length - 1);
        if (from.lastIndexOf('/') === -1)
          throw new Error(`Cannot find DEPS for ${fromDirectory}`);
        from = from.substring(0, from.lastIndexOf('/') + 1);
      }
  
      for (const dep of DEPS[from]) {
        if (to === dep || toDirectory === dep)
          return true;
        if (dep.endsWith('**')) {
          const parent = dep.substring(0, dep.length - 2);
          if (to.startsWith(parent))
            return true;
        }
      }
      return false;
    }
  }
  
  const DEPS = {};
  
  DEPS['src/protocol/'] = ['src/utils/'];
  DEPS['src/install/'] = ['src/utils/'];
  
  // Client depends on chromium protocol for types.
  DEPS['src/client/'] = ['src/utils/', 'src/protocol/', 'src/server/chromium/protocol.ts'];
  
  DEPS['src/dispatchers/'] = ['src/utils/', 'src/protocol/', 'src/server/**'];
  
  // Generic dependencies for server-side code.
  DEPS['src/server/'] = [
    'src/utils/',
    'src/generated/',
    // Can depend on files directly in the server directory.
    'src/server/',
    // Can depend on any files in these subdirectories.
    'src/server/common/**',
    'src/server/injected/**',
  ];
  
  // No dependencies for code shared between node and page.
  DEPS['src/server/common/'] = [];
  // Strict dependencies for injected code.
  DEPS['src/server/injected/'] = ['src/server/common/'];
  
  // Electron and Clank use chromium internally.
  DEPS['src/server/electron/'] = [...DEPS['src/server/'], 'src/server/chromium/'];
  DEPS['src/server/clank/'] = [...DEPS['src/server/'], 'src/server/chromium/'];
  
  DEPS['src/server/playwright.ts'] = [...DEPS['src/server/'], 'src/server/chromium/', 'src/server/webkit/', 'src/server/firefox/', 'src/server/clank/'];
  DEPS['src/driver.ts'] = DEPS['src/inprocess.ts'] = DEPS['src/browserServerImpl.ts'] = ['src/**'];
  
  // Tracing is a client/server plugin, nothing should depend on it.
  DEPS['src/trace/'] = ['src/utils/', 'src/client/**', 'src/server/**'];
  
  // Debug is a server plugin, nothing should depend on it.
  DEPS['src/debug/'] = ['src/utils/', 'src/generated/', 'src/server/**', 'src/debug/**'];
  
  checkDeps();
  