a couple tweaks to make things work on windows

.gitignore

@@ -0,0 +1 @@
+node_modules

index.js

@@ -11,25 +11,18 @@ var rimraf = require('rimraf')
 var path = require('path')
 var signalExit = require('signal-exit')
 var homedir = require('os-homedir')() + '/.node-spawn-wrap-'
+var winRebase = require('./lib/win-rebase')
 
 var pieces = process.execPath.split(path.sep)
 var cmdname = pieces[pieces.length - 1]
 
 var shim = '#!' + process.execPath + '\n' +
   fs.readFileSync(__dirname + '/shim.js')
 
-var cmdShim = 'SETLOCAL\r\n' +
-  'SET PATHEXT=%PATHEXT:;.JS;=;%\r\n' +
-  process.execPath + ' "%~dp0\\.\\node" %*\r\n'
+var isWindows = require('./lib/is-windows')()
 
-var isWindows = false
 var pathRe = /^PATH=/
-if (process.platform === 'win32' ||
-  process.env.OSTYPE === 'cygwin' ||
-  process.env.OSTYPE === 'msys') {
-  pathRe = /^PATH=/i
-  isWindows = true
-}
+if (isWindows) pathRe = /^PATH=/i
 
 var colon = isWindows ? ';' : ':'
 
@@ -80,19 +73,12 @@ function wrap (argv, env, workingDir) {
       }
     } else if (isWindows && (
         file === path.basename(process.env.comspec) ||
-        file === 'cmd.exe')) {
+        file === 'cmd.exe' ||
+        file === 'cmd'
+      )) {
       cmdi = options.args.indexOf('/c')
       if (cmdi !== -1) {
-        c = options.args[cmdi + 1]
-        re = new RegExp('^\\s*"([^\\s]*(?:node|iojs)) ')
-        match = c.match(re)
-        if (match) {
-          exe = path.basename(match[1]).replace(/\.exe$/, '')
-          if (exe === 'node' || exe === 'iojs' || exe === cmdname) {
-            c = c.replace(re, exe + ' ')
-            options.args[cmdi + 1] = c
-          }
-        }
+        options.args[cmdi + 1] = winRebase(options.args[cmdi + 1], workingDir + '/node.cmd')
       }
     } else if (file === 'node' || file === 'iojs' || cmdname === file) {
       // make sure it has a main script.
@@ -144,12 +130,31 @@ function wrap (argv, env, workingDir) {
       options.envPairs.push((isWindows ? 'Path=' : 'PATH=') + workingDir)
     }
 
+    if (isWindows) fixWindowsBins(workingDir, options)
+
     return spawn.call(this, options)
   }
 
   return unwrap
 }
 
+// by default Windows will reference the full
+// path to the node.exe or iojs.exe as the bin,
+// we should instead point spawn() at our .cmd shim.
+function fixWindowsBins (workingDir, options) {
+  var renode = new RegExp('.*node\\.exe$')
+  var reiojs = new RegExp('.*iojs\\.exe$')
+
+  options.file = options.file.replace(renode, workingDir + '/node.cmd')
+  options.file = options.file.replace(reiojs, workingDir + '/node.cmd')
+
+  options.args = options.args.map(function (a) {
+    a = a.replace(renode, workingDir + '/node.cmd')
+    a = a.replace(reiojs, workingDir + '/node.cmd')
+    return a
+  })
+}
+
 function setup (argv, env) {
   if (argv && typeof argv === 'object' && !env && !Array.isArray(argv)) {
     env = argv
@@ -215,6 +220,12 @@ function setup (argv, env) {
   mkdirp.sync(workingDir)
   workingDir = fs.realpathSync(workingDir)
   if (isWindows) {
+    var cmdShim =
+      '@echo off\r\n' +
+      'SETLOCAL\r\n' +
+      'SET PATHEXT=%PATHEXT:;.JS;=;%\r\n' +
+      '"' + process.execPath + '"' + ' "%~dp0\\.\\node" %*\r\n'
+
     fs.writeFileSync(workingDir + '/node.cmd', cmdShim)
     fs.chmodSync(workingDir + '/node.cmd', '0755')
     fs.writeFileSync(workingDir + '/iojs.cmd', cmdShim)

lib/is-windows.js

@@ -0,0 +1,5 @@
+module.exports = function () {
+  return process.platform === 'win32' ||
+    process.env.OSTYPE === 'cygwin' ||
+    process.env.OSTYPE === 'msys'
+}

lib/win-rebase.js

@@ -0,0 +1,7 @@
+var re = new RegExp(/(.*((node\.exe($| ))|(node($| ))|(iojs($| ))|(iojs\.exe($| )))) ?(.*)$/)
+
+module.exports = function (path, rebase) {
+  var m = path.match(re)
+  if (!m) return path
+  return path.replace(m[1].trim(), rebase)
+}

test/basic.js

@@ -1,7 +1,7 @@
 var sw = require('../')
 var onExit = require('signal-exit')
 
-var cp = require('child_process')
+var spawn = require('child_process').spawn
 var fixture = require.resolve('./fixtures/script.js')
 var fs = require('fs')
 var path = require('path')
@@ -38,7 +38,7 @@ var expect = 'WRAP ["{{FIXTURE}}","xyz"]\n' +
   'EXIT [0,null]\n'
 
 t.test('spawn execPath', function (t) {
-  var child = cp.spawn(process.execPath, [fixture, 'xyz'])
+  var child = spawn(process.execPath, [fixture, 'xyz'])
 
   var out = ''
   child.stdout.on('data', function (c) {
@@ -53,7 +53,7 @@ t.test('spawn execPath', function (t) {
 })
 
 t.test('exec shebang', function (t) {
-  var child = cp.exec(fixture + ' xyz')
+  var child = spawn(fixture, ['xyz'])
 
   var out = ''
   child.stdout.on('data', function (c) {
@@ -68,7 +68,7 @@ t.test('exec shebang', function (t) {
 })
 
 t.test('SIGHUP', function (t) {
-  var child = cp.exec(fixture + ' xyz')
+  var child = spawn(fixture, ['xyz'])
 
   var out = ''
   child.stdout.on('data', function (c) {
@@ -88,7 +88,7 @@ t.test('SIGHUP', function (t) {
 })
 
 t.test('SIGINT', function (t) {
-  var child = cp.exec(fixture + ' xyz')
+  var child = spawn(fixture, ['xyz'])
 
   var out = ''
   child.stdout.on('data', function (c) {
@@ -114,7 +114,7 @@ t.test('SIGINT', function (t) {
 
 t.test('--harmony', function (t) {
   var node = process.execPath
-  var child = cp.spawn(node, ['--harmony', fixture, 'xyz'])
+  var child = spawn(node, ['--harmony', fixture, 'xyz'])
   var out = ''
   child.stdout.on('data', function (c) {
     out += c
@@ -135,7 +135,7 @@ t.test('node exe with different name', function(t) {
   var data = fs.readFileSync(process.execPath)
   fs.writeFileSync(fp, data)
   fs.chmodSync(fp, '0775')
-  var child = cp.spawn(process.execPath, [fixture, 'xyz'])
+  var child = spawn(process.execPath, [fixture, 'xyz'])
 
   var out = ''
   child.stdout.on('data', function (c) {

test/win-rebase.js

@@ -0,0 +1,20 @@
+var t = require('tap')
+var winRebase = require('../lib/win-rebase')
+
+t.test('it replaces path to node bin', function (t) {
+  var result = winRebase('C:\\Program Files\\nodejs\\node.exe', 'C:\\foo')
+  t.equal(result, 'C:\\foo')
+  t.done()
+})
+
+t.test('it does not replace path if it references an unknown bin', function (t) {
+  var result = winRebase('C:\\Program Files\\nodejs\\banana', 'C:\\foo')
+  t.equal(result, 'C:\\Program Files\\nodejs\\banana')
+  t.done()
+})
+
+t.test('replaces node bin and leaves the script being executed', function (t) {
+  var result = winRebase('C:\\Program Files\\nodejs\\node.exe foo.js', 'C:\\foo')
+  t.equal(result, 'C:\\foo foo.js')
+  t.done()
+})