react-native-devtools-frontend/test/shared/debug-check.ts

// Copyright 2020 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import {readFileSync} from 'fs';
import {join} from 'path';

const isDebug = /^\s*is_debug\s*=\s*(.*)/;

/**
 * Tests the args.gn file to ensure that the is_debug flag is set to true.
 * We don't cover every case here, for example where is_debug is redefined
 * in the gn.args several times. Instead we use the first declaration of
 * is_debug's value.
 */
export function debugCheck(dirName: string): boolean {
  const argsFile = join(dirName, '..', '..', 'args.gn');
  try {
    const fileDetails = readFileSync(argsFile, {encoding: 'utf8'});
    for (const line of fileDetails.split('\n')) {
      if (!isDebug.test(line)) {
        continue;
      }

      const matches = isDebug.exec(line);
      // For any match we expect:
      // 0: the whole line
      // 1: the value itself
      if (!matches || matches.length < 2) {
        return false;
      }

      const value = matches[1].toLowerCase();
      if (value === 'true' || value === '1') {
        return true;
      }

      return false;
    }
    // By default, a DevTools build is always a debug build,
    // unless `is_debug` is explicitly set to false
    return true;
  } catch {
    return false;
  }
}