fix(fs): Use graceful-fs instead of fs directly (#221)

Prevent `'EMFILE'` errors amongst others by using graceful-fs as a drop-in replacement for file system IO.

package.json

@@ -48,6 +48,7 @@
     "escodegen": "^1.8.0",
     "esprima": "^2.7.0",
     "glob": "^7.0.3",
+    "graceful-fs": "^4.1.11",
     "istanbul": "^0.4.5",
     "lodash": "^3.10.1",
     "log4js": "^0.6.33",
@@ -62,6 +63,7 @@
     "@types/esprima": "^2.1.31",
     "@types/estree": "0.0.32",
     "@types/glob": "^5.0.29",
+    "@types/graceful-fs": "^2.0.29",
     "@types/istanbul": "^0.4.29",
     "@types/karma": "^0.13.32",
     "@types/lodash": "^4.14.34",

src/PluginLoader.ts

@@ -1,4 +1,4 @@
-import * as fs from 'fs';
+import * as fs from 'graceful-fs';
 import * as path from 'path';
 import * as log4js from 'log4js';
 import * as _ from 'lodash';

src/utils/StrykerTempFolder.ts

@@ -1,5 +1,5 @@
 import * as os from 'os';
-import * as fs from 'fs';
+import * as fs from 'graceful-fs';
 import * as path from 'path';
 import * as mkdirp from 'mkdirp';
 import * as fileUtils from './fileUtils';
@@ -77,7 +77,7 @@ function writeFile(filename: string, data: string): Promise<void> {
  * Copies a file.
  * @param fromFilename The path to the existing file.
  * @param toFilename The path to copy the file to.
- * @param instrumenter An optional additional intrumenter to stream the file through
+ * @param instrumenter An optional additional instrumenter to stream the file through
  * @returns A promise to eventually copy the file.
  */
 function copyFile(fromFilename: string, toFilename: string, instrumenter?: NodeJS.ReadWriteStream): Promise<void> {

src/utils/fileUtils.ts

@@ -1,9 +1,7 @@
-'use strict';
-
+import * as path from 'path';
+import * as os from 'os';
+import * as fs from 'graceful-fs';
 import * as _ from 'lodash';
-import fs = require('fs');
-import os = require('os');
-import path = require('path');
 import * as nodeGlob from 'glob';
 import * as mkdirp from 'mkdirp';
 

test/integration/utils/fileUtilsSpec.ts

@@ -1,4 +1,4 @@
-import * as fs from 'fs';
+import * as fs from 'graceful-fs';
 import { expect } from 'chai';
 import * as sinon from 'sinon';
 import * as fileUtils from '../../../src/utils/fileUtils';

test/unit/PluginLoaderSpec.ts

@@ -1,10 +1,10 @@
-import PluginLoader from '../../src/PluginLoader';
-import {expect} from 'chai';
+import * as path from 'path';
+import * as fs from 'graceful-fs';
 import * as sinon from 'sinon';
+import { expect } from 'chai';
 import * as fileUtils from '../../src/utils/fileUtils';
+import PluginLoader from '../../src/PluginLoader';
 import log from '../helpers/log4jsMock';
-import * as fs from 'fs';
-import * as path from 'path';
 
 describe('PluginLoader', () => {
   let sut: PluginLoader;