react-native/packager/react-packager/src/node-haste/__mocks__/graceful-fs.js

A framework for building native apps using React

/**
 * Copyright (c) 2015-present, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 */
'use strict';

const {dirname} = require.requireActual('path');
const fs = jest.genMockFromModule('fs');
const path = require('path');
const stream = require.requireActual('stream');

const noop = () => {};

function asyncCallback(cb) {
  return function() {
    setImmediate(() => cb.apply(this, arguments));
  };
}

const mtime = {
  getTime: () => Math.ceil(Math.random() * 10000000),
};

fs.realpath.mockImpl((filepath, callback) => {
  callback = asyncCallback(callback);
  let node;
  try {
    node = getToNode(filepath);
  } catch (e) {
    return callback(e);
  }
  if (node && typeof node === 'object' && node.SYMLINK != null) {
    return callback(null, node.SYMLINK);
  }
  callback(null, filepath);
});

fs.readdirSync.mockImpl((filepath) => Object.keys(getToNode(filepath)));

fs.readdir.mockImpl((filepath, callback) => {
  callback = asyncCallback(callback);
  let node;
  try {
    node = getToNode(filepath);
    if (node && typeof node === 'object' && node.SYMLINK != null) {
      node = getToNode(node.SYMLINK);
    }
  } catch (e) {
    return callback(e);
  }

  if (!(node && typeof node === 'object' && node.SYMLINK == null)) {
    return callback(new Error(filepath + ' is not a directory.'));
  }

  callback(null, Object.keys(node));
});

fs.readFile.mockImpl(function(filepath, encoding, callback) {
  callback = asyncCallback(callback);
  if (arguments.length === 2) {
    callback = encoding;
    encoding = null;
  }

  let node;
  try {
    node = getToNode(filepath);
    // dir check
    if (node && typeof node === 'object' && node.SYMLINK == null) {
      callback(new Error('Error readFile a dir: ' + filepath));
    }
    if (node == null) {
      callback(Error('No such file: ' + filepath));
    } else {
      callback(null, node);
    }
  } catch (e) {
    return callback(e);
  }
});

fs.readFileSync.mockImpl(function(filepath, encoding) {
  const node = getToNode(filepath);
  // dir check
  if (node && typeof node === 'object' && node.SYMLINK == null) {
    throw new Error('Error readFileSync a dir: ' + filepath);
  }
  return node;
});

fs.stat.mockImpl((filepath, callback) => {
  callback = asyncCallback(callback);
  let node;
  try {
    node = getToNode(filepath);
  } catch (e) {
    callback(e);
    return;
  }

  if (node.SYMLINK) {
    fs.stat(node.SYMLINK, callback);
    return;
  }

  if (node && typeof node === 'object') {
    callback(null, {
      isDirectory: () => true,
      isSymbolicLink: () => false,
      mtime,
    });
  } else {
    callback(null, {
      isDirectory: () => false,
      isSymbolicLink: () => false,
      mtime,
    });
  }
});

fs.statSync.mockImpl((filepath) => {
  const node = getToNode(filepath);

  if (node.SYMLINK) {
    return fs.statSync(node.SYMLINK);
  }

  return {
    isDirectory: () => node && typeof node === 'object',
    isSymbolicLink: () => false,
    mtime,
  };
});

fs.lstat.mockImpl((filepath, callback) => {
  callback = asyncCallback(callback);
  let node;
  try {
    node = getToNode(filepath);
  } catch (e) {
    callback(e);
    return;
  }

  if (node && typeof node === 'object') {
    callback(null, {
      isDirectory: () => true,
      isSymbolicLink: () => false,
      mtime,
    });
  } else {
    callback(null, {
      isDirectory: () => false,
      isSymbolicLink: () => false,
      mtime,
    });
  }
});

fs.lstatSync.mockImpl((filepath) => {
  const node = getToNode(filepath);

  if (node.SYMLINK) {
    return {
      isDirectory: () => false,
      isSymbolicLink: () => true,
      mtime,
    };
  }

  return {
    isDirectory: () => node && typeof node === 'object',
    isSymbolicLink: () => false,
    mtime,
  };
});

fs.open.mockImpl(function(filepath) {
  const callback = arguments[arguments.length - 1] || noop;
  let data, error, fd;
  try {
    data = getToNode(filepath);
  } catch (e) {
    error = e;
  }

  if (error || data == null) {
    error = Error(`ENOENT: no such file or directory, open ${filepath}`);
  }
  if (data != null) {
    /* global Buffer: true */
    fd = {buffer: new Buffer(data, 'utf8'), position: 0};
  }

  callback(error, fd);
});

fs.read.mockImpl((fd, buffer, writeOffset, length, position, callback = noop) => {
  let bytesWritten;
  try {
    if (position == null || position < 0) {
      ({position} = fd);
    }
    bytesWritten = fd.buffer.copy(buffer, writeOffset, position, position + length);
    fd.position = position + bytesWritten;
  } catch (e) {
    callback(Error('invalid argument'));
    return;
  }
  callback(null, bytesWritten, buffer);
});

fs.close.mockImpl((fd, callback = noop) => {
  try {
    fd.buffer = fs.position = undefined;
  } catch (e) {
    callback(Error('invalid argument'));
    return;
  }
  callback(null);
});

let filesystem;

fs.createReadStream.mockImpl(filepath => {
  if (!filepath.startsWith('/')) {
    throw Error('Cannot open file ' + filepath);
  }

  const parts = filepath.split('/').slice(1);
  let file = filesystem;

  for (const part of parts) {
    file = file[part];
    if (!file) {
      break;
    }
  }

  if (typeof file !== 'string') {
    throw Error('Cannot open file ' + filepath);
  }

  return new stream.Readable({
    read() {
      this.push(file, 'utf8');
      this.push(null);
    }
  });
});

fs.createWriteStream.mockImpl(file => {
  let node;
  try {
    node = getToNode(dirname(file));
  } finally {
    if (typeof node === 'object') {
      const writeStream = new stream.Writable({
        write(chunk) {
          this.__chunks.push(chunk);
        }
      });
      writeStream.__file = file;
      writeStream.__chunks = [];
      writeStream.end = jest.fn(writeStream.end);
      fs.createWriteStream.mock.returned.push(writeStream);
      return writeStream;
    } else {
      throw new Error('Cannot open file ' + file);
    }
  }
});
fs.createWriteStream.mock.returned = [];


fs.__setMockFilesystem = (object) => (filesystem = object);

function getToNode(filepath) {
  // Ignore the drive for Windows paths.
  if (filepath.match(/^[a-zA-Z]:\\/)) {
    filepath = filepath.substring(2);
  }

  if (filepath.endsWith(path.sep)) {
    filepath = filepath.slice(0, -1);
  }
  const parts = filepath.split(/[\/\\]/);
  if (parts[0] !== '') {
    throw new Error('Make sure all paths are absolute.');
  }
  let node = filesystem;
  parts.slice(1).forEach((part) => {
    if (node && node.SYMLINK) {
      node = getToNode(node.SYMLINK);
    }
    node = node[part];
  });

  return node;
}

module.exports = fs;