callbackify - npm Package Compare versions

Comparing version 1.0.0 to 1.1.0

index.js

@@ -20,2 +20,21 @@ function callbackify(fn) {
 
+function callbackifyVariadic(fn) {
+  return function () {
+    var args = [].slice.call(arguments)
+    var ctx = this
+    if (args.length >= 1 &&
+        typeof args[args.length - 1] === 'function') {
+      // callback mode
+      var cb = args.pop()
+      fn.apply(this, args)
+        .then(function (val) { cb.call(ctx, null, val) },
+          function (err) { cb.call(ctx, err) })
+        return
+    }
+    // promise mode
+    return fn.apply(ctx, arguments)
+  }
+}
+
 module.exports = callbackify
+module.exports.variadic = callbackifyVariadic;

package.json

 {
   "name": "callbackify",
   "author": "jden <[e-mail]>",
-  "version": "1.0.0",
+  "version": "1.1.0",
   "description": "backwards compatibilify your callback functions while migrating apis to promises",
@@ -6,0 +6,0 @@ "keywords": [

README.md

@@ -35,4 +35,25 @@ # callbackify
 
-Note, `callbackify` only works on fixed-parameter length functions, not variadic functions. It determines whether or not you're passing in a continuation callback by counting parameters. If you can think of a more clever way, please send a PR!
+Normally, callbackify will only work with fixed-parameter-length functions, and will use the declared
+parameter length to determine if the extra callback argument is present.  If you need to use
+callbackify with variadic functions, or functions that don't declare their full argument
+list, you can use:
+```js
+// options argument is optional
+var getUserById = callbackify.variadic(function (id, options) {
+  if (options === undefined) { options = {} }
+  if (options.select) {
+    return db.users.byId(id).select(options.select).first()
+  } else {
+    return db.users.byId(id).first()
+  }
+})
 
+// we can do either of these
+getUserById(23, function (err, user) { })
+getUserById(23, { select: [ 'name' ] }, function (err, user) {} )
+```
+Note that this will not work if the last argument your function can take
+is a function, as that last argument will always be detected as a callback
+function.
+
 ## api
@@ -39,0 +60,0 @@

test/test.js

@@ -83,2 +83,14 @@ var chai = require('chai')
 
+  it('detects the callback with variadic functions', function (done) {
+    var foo = callbackify.variadic(function () {
+      return Promise.resolve(arguments[0])
+    })
+
+    foo(44, function (err, val) {
+      val.should.equal(44)
+      done()
+    })
+
+  })
+
 })

No alert changes

Improved metrics

Total package byte prevSize

6987

25.46%

Lines of code

109

32.93%

Number of lines in readme file

86

32.31%

No dependency changes