/** * Load and modify part of fs to ensure writeFile will crash after writing 5000 bytes */ var fs = require('fs'); function rethrow() { // Only enable in debug mode. A backtrace uses ~1000 bytes of heap space and // is fairly slow to generate. if (DEBUG) { var backtrace = new Error(); return function(err) { if (err) { backtrace.stack = err.name + ': ' + err.message + backtrace.stack.substr(backtrace.name.length); throw backtrace; } }; } return function(err) { if (err) { throw err; // Forgot a callback but don't know where? Use NODE_DEBUG=fs } }; } function maybeCallback(cb) { return typeof cb === 'function' ? cb : rethrow(); } function isFd(path) { return (path >>> 0) === path; } function assertEncoding(encoding) { if (encoding && !Buffer.isEncoding(encoding)) { throw new Error('Unknown encoding: ' + encoding); } } var onePassDone = false; function writeAll(fd, isUserFd, buffer, offset, length, position, callback_) { var callback = maybeCallback(arguments[arguments.length - 1]); if (onePassDone) { process.exit(1); } // Crash on purpose before rewrite done var l = Math.min(5000, length); // Force write by chunks of 5000 bytes to ensure data will be incomplete on crash // write(fd, buffer, offset, length, position, callback) fs.write(fd, buffer, offset, l, position, function(writeErr, written) { if (writeErr) { if (isUserFd) { if (callback) callback(writeErr); } else { fs.close(fd, function() { if (callback) callback(writeErr); }); } } else { onePassDone = true; if (written === length) { if (isUserFd) { if (callback) callback(null); } else { fs.close(fd, callback); } } else { offset += written; length -= written; if (position !== null) { position += written; } writeAll(fd, isUserFd, buffer, offset, length, position, callback); } } }); } fs.writeFile = function(path, data, options, callback_) { var callback = maybeCallback(arguments[arguments.length - 1]); if (!options || typeof options === 'function') { options = { encoding: 'utf8', mode: 438, flag: 'w' }; // Mode 438 == 0o666 (compatibility with older Node releases) } else if (typeof options === 'string') { options = { encoding: options, mode: 438, flag: 'w' }; // Mode 438 == 0o666 (compatibility with older Node releases) } else if (typeof options !== 'object') { throwOptionsError(options); } assertEncoding(options.encoding); var flag = options.flag || 'w'; if (isFd(path)) { writeFd(path, true); return; } fs.open(path, flag, options.mode, function(openErr, fd) { if (openErr) { if (callback) callback(openErr); } else { writeFd(fd, false); } }); function writeFd(fd, isUserFd) { var buffer = (data instanceof Buffer) ? data : new Buffer('' + data, options.encoding || 'utf8'); var position = /a/.test(flag) ? null : 0; writeAll(fd, isUserFd, buffer, 0, buffer.length, position, callback); } }; // End of fs modification var Nedb = require('../lib/datastore.js') , db = new Nedb({ filename: 'workspace/lac.db' }) ; db.loadDatabase();