From 5c8059ac6662c2984e7c3584afbb22decfc353d4 Mon Sep 17 00:00:00 2001
From: Marwan Hilmi <mhilmi@gmail.com>
Date: Wed, 20 Jan 2016 23:34:05 -0800
Subject: [PATCH 1/2] Overwrite option

---
 index.js     | 20 ++++++++++++++++++--
 package.json |  1 +
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/index.js b/index.js
index 8367535..f86fa7d 100644
--- a/index.js
+++ b/index.js
@@ -7,6 +7,7 @@ var debug = require('debug')('extract-zip')
 
 module.exports = function (zipPath, opts, cb) {
   debug('creating target directory', opts.dir)
+  opts.overwrite = opts.overwrite || false
 
   mkdirp(opts.dir, function (err) {
     if (err) return cb(err)
@@ -122,11 +123,15 @@ module.exports = function (zipPath, opts, cb) {
               console.log('read err', err)
             })
 
-            if (symlink) writeSymlink()
+            if (symlink) {
+              if (opts.overwrite) overwriteExistingSymlink()
+              else writeSymlink()
+            }
             else writeStream()
 
             function writeStream () {
-              var writeStream = fs.createWriteStream(dest, {mode: procMode})
+              var writeFlag = opts.overwrite ? 'w' : 'wx'
+              var writeStream = fs.createWriteStream(dest, {mode: procMode, flag: writeFlag})
               readStream.pipe(writeStream)
 
               writeStream.on('finish', function () {
@@ -139,6 +144,17 @@ module.exports = function (zipPath, opts, cb) {
                 return done(err)
               })
             }
+            // Attempt to delete an existing symlink before attempting to write
+            function overwriteExistingSymlink () {
+              fs.unlink(dest, function (err) {
+                if (err) {
+                  if (err.code === 'ENOENT') return writeSymlink()
+                  cancelled = true
+                  done(err)
+                }
+                writeSymlink()
+              })
+            }
 
             // AFAICT the content of the symlink file itself is the symlink target filename string
             function writeSymlink () {
diff --git a/package.json b/package.json
index 0432504..672cf7a 100644
--- a/package.json
+++ b/package.json
@@ -28,6 +28,7 @@
     "concat-stream": "1.5.0",
     "debug": "0.7.4",
     "mkdirp": "0.5.0",
+    "path-exists": "^1.0.0",
     "yauzl": "2.4.1"
   },
   "devDependencies": {

From 5d7eca63f3e70ee346d33d0f99a194fc6b9f040f Mon Sep 17 00:00:00 2001
From: Marwan Hilmi <mhilmi@gmail.com>
Date: Thu, 21 Jan 2016 00:24:58 -0800
Subject: [PATCH 2/2] Add some tests

---
 index.js     |  4 ++--
 package.json |  1 -
 test/test.js | 32 ++++++++++++++++++++++++++++++--
 3 files changed, 32 insertions(+), 5 deletions(-)

diff --git a/index.js b/index.js
index f86fa7d..df4e9b4 100644
--- a/index.js
+++ b/index.js
@@ -7,7 +7,7 @@ var debug = require('debug')('extract-zip')
 
 module.exports = function (zipPath, opts, cb) {
   debug('creating target directory', opts.dir)
-  opts.overwrite = opts.overwrite || false
+  opts.overwrite = (typeof opts.overwrite === 'undefined') ? true : opts.overwrite
 
   mkdirp(opts.dir, function (err) {
     if (err) return cb(err)
@@ -131,7 +131,7 @@ module.exports = function (zipPath, opts, cb) {
 
             function writeStream () {
               var writeFlag = opts.overwrite ? 'w' : 'wx'
-              var writeStream = fs.createWriteStream(dest, {mode: procMode, flag: writeFlag})
+              var writeStream = fs.createWriteStream(dest, {mode: procMode, flags: writeFlag})
               readStream.pipe(writeStream)
 
               writeStream.on('finish', function () {
diff --git a/package.json b/package.json
index 672cf7a..0432504 100644
--- a/package.json
+++ b/package.json
@@ -28,7 +28,6 @@
     "concat-stream": "1.5.0",
     "debug": "0.7.4",
     "mkdirp": "0.5.0",
-    "path-exists": "^1.0.0",
     "yauzl": "2.4.1"
   },
   "devDependencies": {
diff --git a/test/test.js b/test/test.js
index 4d8032d..3a32d75 100644
--- a/test/test.js
+++ b/test/test.js
@@ -28,6 +28,25 @@ test('extract cat zip', function (t) {
   })
 })
 
+test('extract cat zip to same dir without overwrite', function (t) {
+  console.log('extracting again to', targetA)
+
+  extract(sourceA, {dir: targetA, overwrite: false}, function (err) {
+    if (err) t.ok(true, 'error passed')
+    t.end()
+  })
+})
+
+test('extract cat zip to same dir with overwrite', function (t) {
+  console.log('extracting again to', targetA)
+
+  extract(sourceA, {dir: targetA, overwrite: true}, function (err) {
+    if (err) throw err
+    t.false(err, 'no error')
+    t.end()
+  })
+})
+
 test('files', function (t) {
   t.plan(1)
 
@@ -95,6 +114,16 @@ test('verify extraction worked', function (t) {
   })
 })
 
+test('extract github zip again without overwrite', function (t) {
+  console.log('extracting again to', targetB)
+  t.plan(1)
+
+  extract(sourceB, {dir: targetB, overwrite: false}, function (err) {
+    if (err) t.ok(true, 'error passed')
+    t.end()
+  })
+})
+
 test('callback called once', function (t) {
   rimraf.sync(targetC)
 
@@ -106,9 +135,8 @@ test('callback called once', function (t) {
     if (err) throw err
 
     // this triggers an error due to symlink creation
-    extract(sourceC, {dir: targetC}, function (err) {
+    extract(sourceC, {dir: targetC, overwrite: false}, function (err) {
       if (err) t.ok(true, 'error passed')
-
       t.ok(true, 'callback called')
     })
   })