From 707195e4aa5cd1dd9279c2431685870d53d1589b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?C=C3=A9sar=20Carruitero?= <ccarruitero@protonmail.com>
Date: Thu, 18 Jun 2020 19:46:44 -0500
Subject: [PATCH] fix(make_it_modular): use proxyquire for mock fs

to avoid fail verification when use destructuring assignment
---
 exercises/make_it_modular/verify.js     | 21 ++++++++++-----------
 package.json                            |  1 +
 test/make_it_modular/module_valid_03.js | 13 +++++++++++++
 test/make_it_modular/valid_03.js        |  9 +++++++++
 4 files changed, 33 insertions(+), 11 deletions(-)
 create mode 100644 test/make_it_modular/module_valid_03.js
 create mode 100644 test/make_it_modular/valid_03.js

diff --git a/exercises/make_it_modular/verify.js b/exercises/make_it_modular/verify.js
index ec7aaf33..091d8644 100644
--- a/exercises/make_it_modular/verify.js
+++ b/exercises/make_it_modular/verify.js
@@ -1,7 +1,7 @@
-const fs = require('fs')
 const path = require('path')
 const util = require('util')
 const files = require('../filtered_ls/file-list')
+const proxyquire = require('proxyquire')
 
 function validateModule (modFile, callback) {
   const exercise = this
@@ -48,12 +48,14 @@ function validateModule (modFile, callback) {
   exercise.emit('pass', __n('pass.arguments', mod.length))
 
   // ---- Mock `fs.readdir` and check that an error bubbles back up through the cb
-
-  fs.$readdir = fs.readdir
-  fs.readdir = function (dir, optionalEncoding, callback) {
-    callback = callback || optionalEncoding
-    callback(error)
-  }
+  const mockMod = proxyquire(modFile, {
+    fs: {
+      readdir: function (dir, optionalEncoding, callback) {
+        callback = callback || optionalEncoding
+        callback(error)
+      }
+    }
+  })
 
   function noerr () {
     return modFileError(__('fail.mod.missing_error'))
@@ -61,7 +63,7 @@ function validateModule (modFile, callback) {
 
   callbackUsed = false
   try {
-    mod('/foo/bar/', 'wheee', function (err) {
+    mockMod('/foo/bar/', 'wheee', function (err) {
       if (err !== error) {
         return noerr()
       }
@@ -89,9 +91,6 @@ function validateModule (modFile, callback) {
 
     exercise.emit('pass', __('pass.callback'))
 
-    // replace the mock readdir
-    fs.readdir = fs.$readdir
-
     callbackUsed = false
 
     // a special follow-up for when we detect they are not passing back
diff --git a/package.json b/package.json
index 1addd8c8..caf62f0a 100644
--- a/package.json
+++ b/package.json
@@ -66,6 +66,7 @@
     "concat-stream": "^2.0.0",
     "duplexer": "^0.1.1",
     "hyperquest": "^2.1.3",
+    "proxyquire": "^2.1.3",
     "rimraf": "^3.0.0",
     "through2": "^3.0.1",
     "through2-map": "^3.0.0",
diff --git a/test/make_it_modular/module_valid_03.js b/test/make_it_modular/module_valid_03.js
new file mode 100644
index 00000000..de1d42a4
--- /dev/null
+++ b/test/make_it_modular/module_valid_03.js
@@ -0,0 +1,13 @@
+const { readdir } = require('fs')
+const { extname } = require('path')
+
+module.exports = (directory, extension, callback) => {
+  const isExtension = (file) => extname(file) === `.${extension}`
+
+  readdir(directory, (err, files) => {
+    if (err) return callback(err)
+
+    const matchingFiles = files.filter(isExtension)
+    callback(null, matchingFiles)
+  })
+}
diff --git a/test/make_it_modular/valid_03.js b/test/make_it_modular/valid_03.js
new file mode 100644
index 00000000..b1eea7bd
--- /dev/null
+++ b/test/make_it_modular/valid_03.js
@@ -0,0 +1,9 @@
+const mod = require('./module_valid_03')
+
+mod(process.argv[2], process.argv[3], (error, list) => {
+  if (error) return console.log(error)
+
+  list.forEach((entry) => {
+    console.log(entry)
+  })
+})