Only override process.binding('fs')

tschaub · Nov 1, 2016 · 4426ebc · 4426ebc
1 parent 479d815
commit 4426ebc
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Showing 15 changed files with 31 additions and 24,532 deletions.
diff --git a/lib/index.js b/lib/index.js
@@ -1,83 +1,45 @@
 'use strict';
 
-var realFs = require('fs');
-var path = require('path');
-
-var rewire = require('rewire');
-var semver = require('semver');
-
 var Binding = require('./binding');
-var FileSystem = require('./filesystem');
 var FSError = require('./error');
-
-var versions = {
-  '0.8.x': 'fs-0.8.26.js',
-  '0.9.x': 'fs-0.9.12.js',
-  '0.10.x': 'fs-0.10.28.js',
-  '0.11 - 0.11.14': 'fs-0.11.13.js',
-  '0.11.15 - 0.12.x': 'fs-0.12.0.js',
-  '1.x.x': 'fs-1.1.0.js',
-  '2.x.x': 'fs-2.0.0.js',
-  '3.x.x': 'fs-3.0.0.js',
-  '4.x.x': 'fs-4.0.0.js',
-  '5.x.x': 'fs-5.0.0.js',
-  '6.x.x': 'fs-6.3.0.js',
-  '7.x.x': 'fs-7.0.0.js'
-};
-var nodeVersion = process.versions.node;
-var fsName;
-
-Object.keys(versions).some(function(version) {
-  if (semver.satisfies(nodeVersion, version)) {
-    fsName = versions[version];
-    return true;
-  }
-});
-
-if (!fsName) {
-  throw new Error('Unsupported Node version: ' + nodeVersion);
-}
+var FileSystem = require('./filesystem');
+var realBinding = process.binding('fs');
+var path = require('path');
 
 
-/**
- * Hijack the real fs module immediately so the binding can be swapped at will.
- * This works as expected in cases where mock-fs is required before any other
- * module that wraps fs exports.
- */
-var mockFs = rewire(path.join(__dirname, '..', 'node', fsName));
-var originalBinding = mockFs.__get__('binding');
-var originalStats = mockFs.Stats;
-for (var name in mockFs) {
-  var descriptor = Object.getOwnPropertyDescriptor(realFs, name);
-
-  if (!descriptor || descriptor && descriptor.writable) {
-    realFs[name] = (function(mockFunction, realFunction) {
-      return function() {
-        var stack = new Error().stack;
-        if (stack.indexOf('at Module.require (module') >= 0) {
-          return realFunction.apply(realFs, arguments);
-        } else {
-          return mockFunction.apply(realFs, arguments);
-        }
-      };
-    }(mockFs[name], realFs[name]));
-  }
-}
-var originalProcess = {
+var realBindingProps = Object.assign({}, realBinding);
+var realProcessProps = {
   cwd: process.cwd,
   chdir: process.chdir
 };
 
-function setBinding(binding, Stats) {
-  mockFs.__set__('binding', binding);
-  mockFs.Stats = realFs.Stats = Stats;
+
+function overrideBinding(binding) {
+  for (var key in binding) {
+    if (typeof binding[key] === 'function') {
+      realBinding[key] = binding[key].bind(binding);
+    } else {
+      realBinding[key] = binding[key];
+    }
+  }
 }
 
-function setProcess(cwd, chdir) {
+function overrideProcess(cwd, chdir) {
   process.cwd = cwd;
   process.chdir = chdir;
 }
 
+function restoreBinding() {
+  for (var key in realBindingProps) {
+    realBinding[key] = realBindingProps[key];
+  }
+}
+
+function restoreProcess() {
+  for (var key in realProcessProps) {
+    process[key] = realProcessProps[key];
+  }
+}
 
 /**
  * Swap out the fs bindings for a mock file system.
@@ -91,15 +53,15 @@ function setProcess(cwd, chdir) {
 var exports = module.exports = function mock(config, options) {
   var system = FileSystem.create(config, options);
   var binding = new Binding(system);
-  setBinding(binding, binding.Stats);
+  overrideBinding(binding);
 
   var currentPath = process.cwd();
-  setProcess(
+  overrideProcess(
     function cwd() {
       return currentPath;
     },
     function chdir(directory) {
-      if (!mockFs.statSync(directory).isDirectory()) {
+      if (!binding.stat(path._makeLong(directory)).isDirectory()) {
         throw new FSError('ENOTDIR');
       }
       currentPath = path.resolve(currentPath, directory);
@@ -112,33 +74,8 @@ var exports = module.exports = function mock(config, options) {
  * Restore the fs bindings for the real file system.
  */
 exports.restore = function() {
-  setBinding(originalBinding, originalStats);
-  setProcess(originalProcess.cwd, originalProcess.chdir);
-};
-
-
-/**
- * Create a mock fs module based on the given file system configuration.
- * @param {Object} config File system configuration.
- * @param {Object} options Any filesystem options.
- * @param {boolean} options.createCwd Create a directory for `process.cwd()`
- *     (defaults to `true`).
- * @param {boolean} options.createTmp Create a directory for `os.tmpdir()`
- *     (defaults to `true`).
- * @return {Object} A fs module with a mock file system.
- */
-exports.fs = function(config, options) {
-  var system = FileSystem.create(config, options);
-  var binding = new Binding(system);
-
-  // inject the mock binding
-  var newMockFs = rewire(path.join(__dirname, '..', 'node', fsName));
-  newMockFs.__set__('binding', binding);
-
-  // overwrite fs.Stats from original binding
-  newMockFs.Stats = binding.Stats;
-
-  return newMockFs;
+  restoreBinding();
+  restoreProcess();
 };