Added Promise wrap to async methods

README.md

@@ -60,7 +60,7 @@ require(["bcrypt"], function(bcrypt) {
 
 Usage - Sync
 ------------
-To hash a password: 
+To hash a password:
 
 ```javascript
 var bcrypt = require('bcryptjs');
@@ -69,7 +69,7 @@ var hash = bcrypt.hashSync("B4c0/\/", salt);
 // Store hash in your password DB.
 ```
 
-To check a password: 
+To check a password:
 
 ```javascript
 // Load hash from your password DB.
@@ -85,7 +85,7 @@ var hash = bcrypt.hashSync('bacon', 8);
 
 Usage - Async
 -------------
-To hash a password: 
+To hash a password:
 
 ```javascript
 var bcrypt = require('bcryptjs');
@@ -96,7 +96,7 @@ bcrypt.genSalt(10, function(err, salt) {
 });
 ```
 
-To check a password: 
+To check a password:
 
 ```javascript
 // Load hash from your password DB.
@@ -115,6 +115,46 @@ bcrypt.hash('bacon', 8, function(err, hash) {
 });
 ```
 
+Usage-Promises
+--------------
+When bcrypt async functions are called without a callback promise is returned.
+
+To hash a password:
+
+```javascript
+var bcrypt = require('bcryptjs');
+bcrypt.genSalt(10)
+.then(function(salt) {
+    return bcrypt.hash("B4c0/\/", salt);
+}, function(err) {//...})
+.then(function(hash) {
+    // Store hash in your password DB.
+}, function(err) {//...});
+```
+
+To check a password:
+
+```javascript
+// Load hash from your password DB.
+bcrypt.compare("B4c0/\/", hash)
+.then(function(res) {
+    // res == true
+},
+function(err) {//...});
+bcrypt.compare("not_bacon", hash)
+.then(function(res) {
+    // res == false
+},
+function(err) {//...});
+```
+
+Auto-gen a salt and hash:
+
+```javascript
+bcrypt.hash('bacon', 8)
+.then(function(hash) {}, function(err) {});
+```
+
 API
 ---
 ### setRandomFallback(random)
@@ -125,8 +165,8 @@ seeded properly!
 
 | Parameter       | Type            | Description
 |-----------------|-----------------|---------------
-| random          | *function(number):!Array.<number>* | Function taking the number of bytes to generate as its sole argument, returning the corresponding array of cryptographically secure random byte values. 
-| **@see**        |                 | http://nodejs.org/api/crypto.html 
+| random          | *function(number):!Array.<number>* | Function taking the number of bytes to generate as its sole argument, returning the corresponding array of cryptographically secure random byte values.
+| **@see**        |                 | http://nodejs.org/api/crypto.html
 | **@see**        |                 | http://www.w3.org/TR/WebCryptoAPI/
 
 **Hint:** You might use [isaac.js](https://github.com/rubycon/isaac.js) as a CSPRNG but you still have to make sure to
@@ -138,84 +178,84 @@ Synchronously generates a salt.
 
 | Parameter       | Type            | Description
 |-----------------|-----------------|---------------
-| rounds          | *number*        | Number of rounds to use, defaults to 10 if omitted 
-| seed_length     | *number*        | Not supported. 
-| **@returns**    | *string*        | Resulting salt 
-| **@throws**     | *Error*         | If a random fallback is required but not set 
+| rounds          | *number*        | Number of rounds to use, defaults to 10 if omitted
+| seed_length     | *number*        | Not supported.
+| **@returns**    | *string*        | Resulting salt
+| **@throws**     | *Error*         | If a random fallback is required but not set
 
 ### genSalt(rounds=, seed_length=, callback)
 
 Asynchronously generates a salt.
 
 | Parameter       | Type            | Description
 |-----------------|-----------------|---------------
-| rounds          | *number | function(Error, string=)* | Number of rounds to use, defaults to 10 if omitted 
-| seed_length     | *number | function(Error, string=)* | Not supported. 
-| callback        | *function(Error, string=)* | Callback receiving the error, if any, and the resulting salt 
+| rounds          | *number | function(Error, string=)* | Number of rounds to use, defaults to 10 if omitted
+| seed_length     | *number | function(Error, string=)* | Not supported.
+| callback        | *function(Error, string=)* | Callback receiving the error, if any, and the resulting salt
 
 ### hashSync(s, salt=)
 
 Synchronously generates a hash for the given string.
 
 | Parameter       | Type            | Description
 |-----------------|-----------------|---------------
-| s               | *string*        | String to hash 
-| salt            | *number | string* | Salt length to generate or salt to use, default to 10 
-| **@returns**    | *string*        | Resulting hash 
+| s               | *string*        | String to hash
+| salt            | *number | string* | Salt length to generate or salt to use, default to 10
+| **@returns**    | *string*        | Resulting hash
 
 ### hash(s, salt, callback, progressCallback=)
 
 Asynchronously generates a hash for the given string.
 
 | Parameter       | Type            | Description
 |-----------------|-----------------|---------------
-| s               | *string*        | String to hash 
-| salt            | *number | string* | Salt length to generate or salt to use 
-| callback        | *function(Error, string=)* | Callback receiving the error, if any, and the resulting hash 
-| progressCallback | *function(number)* | Callback successively called with the percentage of rounds completed (0.0 - 1.0), maximally once per `MAX_EXECUTION_TIME = 100` ms. 
+| s               | *string*        | String to hash
+| salt            | *number | string* | Salt length to generate or salt to use
+| callback        | *function(Error, string=)* | Callback receiving the error, if any, and the resulting hash
+| progressCallback | *function(number)* | Callback successively called with the percentage of rounds completed (0.0 - 1.0), maximally once per `MAX_EXECUTION_TIME = 100` ms.
 
 ### compareSync(s, hash)
 
 Synchronously tests a string against a hash.
 
 | Parameter       | Type            | Description
 |-----------------|-----------------|---------------
-| s               | *string*        | String to compare 
-| hash            | *string*        | Hash to test against 
-| **@returns**    | *boolean*       | true if matching, otherwise false 
-| **@throws**     | *Error*         | If an argument is illegal 
+| s               | *string*        | String to compare
+| hash            | *string*        | Hash to test against
+| **@returns**    | *boolean*       | true if matching, otherwise false
+| **@throws**     | *Error*         | If an argument is illegal
 
 ### compare(s, hash, callback, progressCallback=)
 
 Asynchronously compares the given data against the given hash.
 
 | Parameter       | Type            | Description
 |-----------------|-----------------|---------------
-| s               | *string*        | Data to compare 
-| hash            | *string*        | Data to be compared to 
-| callback        | *function(Error, boolean)* | Callback receiving the error, if any, otherwise the result 
-| progressCallback | *function(number)* | Callback successively called with the percentage of rounds completed (0.0 - 1.0), maximally once per `MAX_EXECUTION_TIME = 100` ms. 
-| **@throws**     | *Error*         | If the callback argument is invalid 
+| s               | *string*        | Data to compare
+| hash            | *string*        | Data to be compared to
+| callback        | *function(Error, boolean)* | Callback receiving the error, if any, otherwise the result
+| progressCallback | *function(number)* | Callback successively called with the percentage of rounds completed (0.0 - 1.0), maximally once per `MAX_EXECUTION_TIME = 100` ms.
+| **@throws**     | *Error*         | If the callback argument is invalid
 
 ### getRounds(hash)
 
 Gets the number of rounds used to encrypt the specified hash.
 
 | Parameter       | Type            | Description
 |-----------------|-----------------|---------------
-| hash            | *string*        | Hash to extract the used number of rounds from 
-| **@returns**    | *number*        | Number of rounds used 
-| **@throws**     | *Error*         | If hash is not a string 
+| hash            | *string*        | Hash to extract the used number of rounds from
+| **@returns**    | *number*        | Number of rounds used
+| **@throws**     | *Error*         | If hash is not a string
 
 ### getSalt(hash)
 
 Gets the salt portion from a hash. Does not validate the hash.
 
 | Parameter       | Type            | Description
 |-----------------|-----------------|---------------
-| hash            | *string*        | Hash to extract the salt from 
-| **@returns**    | *string*        | Extracted salt part 
-| **@throws**     | *Error*         | If `hash` is not a string or otherwise invalid 
+| hash            | *string*        | Hash to extract the salt from
+| **@returns**    | *string*        | Extracted salt part
+| **@throws**     | *Error*         | If `hash` is not a string or otherwise invalid
 
 
 Command line

dist/bcrypt.js

@@ -1220,5 +1220,60 @@
      */
     bcrypt.decodeBase64 = base64_decode;
 
+    /**
+     * Names of async bcrypt methods
+     * @type {Array.<string>}
+     * @inner
+     */
+    var asyncMethodNames = [
+      'hash',
+      'genSalt',
+      'compare'
+    ];
+
+    asyncMethodNames.forEach(function(methodName) {
+      bcrypt[methodName] = makePromisePolyfill(bcrypt[methodName]);
+    });
+
+    /**
+     * Curries original method
+     * Returns a promise if last argument passed to the curried function is a function
+     * Calls a callback-style function if last argument passed to the curried function is not a function
+     * @function
+     * @param {function(data1,data2,callback,?progressCallback)} async bcrypt method
+     * @returns {?Promise}
+     * @inner
+     */
+    function makePromisePolyfill(method) {
+      return function() {
+        var args = Array.prototype.slice.call(arguments);
+        var isPromise = typeof args[args.length] !== 'function';
+
+        if (isPromise) return makePromise(method, args);
+        else           return method.apply(bcrypt, args);
+      }
+    }
+
+    /**
+     * Wraps callback-style function in a promise
+     * @function
+     * @param {function(data1,data2,callback,?progressCallback)} callee method
+     * @param {!Array.<(string|number|function)=>} array of callee method's arguments
+     * @returns {Promise}
+     * @inner
+     */
+    function makePromise(method, args) {
+      return new Promise(function(resolve, reject) {
+        function callback(err, res) {
+          if (err) return reject(err);
+
+          resolve(res);
+        }
+
+        args.push(callback);
+        method.apply(bcrypt, args);
+      });
+    }
+
     return bcrypt;
 }));

src/promisePolyfill.js

@@ -0,0 +1,55 @@
+/**
+ * Names of async bcrypt methods
+ * @type {Array.<string>}
+ * @inner
+ */
+var asyncMethodNames = [
+  'hash',
+  'genSalt',
+  'compare'
+];
+
+asyncMethodNames.forEach(function(methodName) {
+  bcrypt[methodName] = makePromisePolyfill(bcrypt[methodName]);
+});
+
+/**
+ * Curries original method
+ * Returns a promise if last argument passed to the curried function is a function
+ * Calls a callback-style function if last argument passed to the curried function is not a function
+ * @function
+ * @param {function(data1,data2,callback,?progressCallback)} async bcrypt method
+ * @returns {?Promise}
+ * @inner
+ */
+function makePromisePolyfill(method) {
+  return function() {
+    var args = Array.prototype.slice.call(arguments);
+    var isPromise = typeof args[args.length] !== 'function';
+    var promisesSupported = typeof Promise !== 'undefined';
+
+    if (isPromise && promisesSupported) return makePromise(method, args);
+    else                                return method.apply(bcrypt, args);
+  }
+}
+
+/**
+ * Wraps callback-style function in a promise
+ * @function
+ * @param {function(data1,data2,callback,?progressCallback)} callee method
+ * @param {!Array.<(string|number|function)=>} array of callee method's arguments
+ * @returns {Promise}
+ * @inner
+ */
+function makePromise(method, args) {
+  return new Promise(function(resolve, reject) {
+    function callback(err, res) {
+      if (err) return reject(err);
+
+      resolve(res);
+    }
+
+    args.push(callback);
+    method.apply(bcrypt, args);
+  });
+}

src/wrap.js

@@ -46,5 +46,7 @@
 
     //? include("bcrypt.js");
 
+    //? include("promisePolyfill.js");
+
     return bcrypt;
 }));