support callback

child_process.js

@@ -1,5 +1,5 @@
 
-require('thenify-all')(
+require('thenify-all').withCallback(
   require('child_process'),
   exports, [
     'exec',

crypto.js

@@ -1,5 +1,5 @@
 
-require('thenify-all')(
+require('thenify-all').withCallback(
   require('crypto'),
   exports, [
     'pbkdf2',

dns.js

@@ -1,5 +1,5 @@
 
-require('thenify-all')(
+require('thenify-all').withCallback(
   require('dns'),
   exports, [
     'lookup',

fs.js

@@ -40,10 +40,16 @@ var api = [
 
 typeof fs.access === 'function' && api.push('access')
 
-require('thenify-all')(fs, exports, api)
+require('thenify-all').withCallback(fs, exports, api)
 
-// don't know enough about promises to do this haha
-exports.exists = function (filename) {
+exports.exists = function (filename, callback) {
+  // callback
+  if (typeof callback === 'function') {
+    return fs.stat(filename, function (err) {
+      callback(null, !err);
+    })
+  }
+  // or promise
   return new Promise(function (resolve) {
     fs.stat(filename, function (err) {
       resolve(!err)

test/mz.js

@@ -27,6 +27,24 @@ describe('fs', function () {
     var exists = fs.existsSync(__filename)
     assert(exists)
   })
+
+  describe('callback support', function () {
+    it('.stat()', function (done) {
+      fs.stat(__filename, function (err, stats) {
+        assert(!err)
+        assert.equal(typeof stats.size, 'number')
+        done()
+      })
+    })
+
+    it('.exists()', function (done) {
+      fs.exists(__filename, function (err, exists) {
+        assert(!err)
+        assert(exists)
+        done()
+      })
+    })
+  })
 })
 
 describe('child_process', function () {
@@ -44,6 +62,22 @@ describe('child_process', function () {
       done()
     })
   })
+
+  describe('callback support', function () {
+    it('.exec() success', function (done) {
+      cp.exec('node --version', function (err, stdout) {
+        assert.equal(stdout.toString('utf8')[0], 'v')
+        done()
+      })
+    })
+
+    it('.exec() err', function (done) {
+      cp.exec('lkajsdfkljalskdfjalsdf', function (err) {
+        assert(err)
+        done()
+      })
+    })
+  })
 })
 
 describe('crypto', function () {
@@ -55,6 +89,16 @@ describe('crypto', function () {
       done()
     })
   })
+
+  describe('callback support', function () {
+    it('.randomBytes()', function (done) {
+      crypto.randomBytes(8, function (err, buf) {
+        assert(!err)
+        assert.equal(buf.length, 8)
+        done()
+      })
+    })
+  })
 })
 
 describe('zlib', function () {
@@ -68,4 +112,18 @@ describe('zlib', function () {
       done()
     })
   })
+
+  describe('callback support', function () {
+    it('.gzip() and .gunzip()', function (done) {
+      zlib.gzip('lol', function (err, res) {
+        assert(!err)
+        assert(Buffer.isBuffer(res))
+        zlib.gunzip(res, function (err, string) {
+          assert(!err)
+          assert.equal(string, 'lol')
+          done()
+        })
+      })
+    })
+  })
 })

zlib.js

@@ -1,5 +1,5 @@
 
-require('thenify-all')(
+require('thenify-all').withCallback(
   require('zlib'),
   exports, [
     'deflate',