when.js

When.js also provides Promise-related concepts.

This refers to joining and chaining.

When.js has a robust unit test suite.

What is new in this release:

• Fix when.settle unhandled rejection reporting case.

What is new in version 3.7.3:

• Fix when.settle unhandled rejection reporting case.

What is new in version 3.7.2:

• Fix when.settle unhandled rejection reporting case.

What is new in version 3.6.3:

• Fixed regression in when/callbacks introduced in 3.6.1.

What is new in version 3.5.2:

• Prevent minifiers from clobbering unhandled rejection reporting if they remove console.* calls. Unhandled rejections will be reported even when using Uglify drop_console.
• when/function.apply now handles passing an Arguments object directly, e.g. fn.apply(f, arguments);. Use with care: v8 will deoptimize any function where you pass arguments to another function.

What is new in version 3.4.4:

• Workaround for node 0.10.30 setTimeout bug.

What is new in version 3.4.1:

• Fix for promise.finally not waiting on returned promises.

What is new in version 3.3.1:

• Fixed argument ordering bug in when/node introduced in 3.3.0.

What is new in version 3.2.3:

• Report when previously unhandled rejections become handled, with an ID to correlate the two.
• Improve unhandled rejection reporting for cases where multiple different promise implementations interleave.

What is new in version 3.2.2:

• More mem and perf improvements.
• Improvements to unhandled rejection reporting.

What is new in version 3.2.1:

• Minor mem and perf tweaks for when.all.
• Defend against JSON.stringify exceptions when formatting unhandled rejection output.

What is new in version 3.0.0:

• New internal architecture with significant performance improvements and memory efficiency
• New APIs
• New ES6 Promise shim

What is new in version 2.8.0:

• Experimental ES6 generator support via new when/generator module, with lift, call, apply.

What is new in version 2.7.0:

• Added promise.catch and promise.finally as synonyms for promise.otherwise and promise.ensure.
• New browserify build for those using globals.
• Added ender support to package.json.
• Fix compatibility with PhantomJS's CommonJS module support.
• Fix Sauce Labs tests for pull requests.

What is new in version 2.6.0:

• New promise.done allows consuming the ultimate value at the end of a promise chain while ensuring that any errors are thrown to the host environment so you get loud stack traces.

What is new in version 2.5.1:

• ensure now ignores non-functions, like then does, for consistency.

What is new in version 2.4.1:

• New MutationObserver scheduler further reduces "time-to-first-handler" in modern browsers.

What is new in version 2.4.0:

• Experimental support for vert.x 2.x. Should now run in vert.x >= 1.1.0.
• New when.isPromiseLike as the more accurately-named synonym for when.isPromise.

What is new in version 2.3.0:

• New promise.tap for adding side effects to a promise chain.
• New MessageChannel scheduler reduces "time-to-first" handler, in environments that support it.
• Performance optimizations for promise resolution.

What is new in version 2.2.1:

• Fix for when.defer().reject() bypassing the unhandled rejection monitor.
• Fix for when/function, when/callbacks, and when/node/function not preserving thisArg.

What is new in version 2.2.0:

• New when.promise(resolver) promise creation API. A lighter alternative to the heavier when.defer().
• New bindCallback and liftCallback in when/node/function for more integration options with node-style callbacks.

What is new in version 2.1.1:

• Quote internal usages of promise.yield to workaround .NET minifier tools that don't yet understand ES5 identifier-as-property rules.

What is new in version 2.1.0:

• Fixed typo in README.

What is new in version 2.0.0:

• Fully asynchronous resolutions.
• Promises/A+ compliance.

What is new in version 1.8.0:

• New when/unfold, and when/unfold/list promise-aware anamorphic unfolds that can be used to generate and/or process unbounded lists.
• New when/poll promise-based periodic polling and task execution.

What is new in version 1.7.0:

• promise.yield(promiseOrValue) convenience API for substituting a new value into a promise chain.
• promise.spread(variadicFunction) convenience API for spreading an array onto a fulfill handler that accepts variadic arguments.
• Doc improvements.

What is new in version 1.6.1:

• Fixed for accidental coercion of non-promises.

What is new in version 1.5.1:

• Performance optimization for when.defer, up to 1.5x in some cases.

What is new in version 1.4.2:

• Fix for IE8 infinite recursion.

What is new in version 1.4.0:

• Create a resolved promise: when.resolve(value) creates a resolved promise for value.
• Resolve/reject return something useful: deferred.resolve and deferred.reject now return a promise for the fulfilled or rejected value.

What is new in version 1.3.1:

• npm install when - Yep, that's a thing.
• Fixed a deviation from the Promises/A spec where returning undefined from a callback or errback would cause the previous value to be forwarded.

What is new in version 1.3.0:

• Fixed a deviation from the Promises/A spec where returning undefined from a callback or errback would cause the previous value to be forwarded.

What is new in version 1.2.0:

• when/debug now detects exceptions that typically represent coding errors, such as SyntaxError, ReferenceError, etc. and propagates them to the host environment. In other words, you'll get a very loud stack trace.

What is new in version 1.1.1:

• Update changelog and version numbers.

What is new in version 1.1.0:

• Highly experimental when/debug module.

What is new in version 1.0.4:

• Fix for cancelable deferred not invoking progress callbacks.
• The promise returned by when.chain now rejects when the input promise rejects.

What is new in version 1.0.3:

• Fix for specific situation where null could incorrectly be used as a promise resolution value.

What is new in version 1.0.1:

• Fix for rejections propagating in some cases when they shouldn't have been.
• Using buster.js for unit tests now.

What is new in version 1.0.0:

• First official when.js release as a part of cujojs.
• Added when/cancelable decorator for creating cancelable deferreds
• Added when/delay and when/timeout helpers for creating delayed promises and promises that timeout and reject if not resolved first.

What is new in version 0.11.1:

• Added when/apply helper module for using arguments-based and variadic callbacks with when.all, when.some, when.map, or any promise that resolves to an array.
• .then(), when(), and all other methods that accept callback/errback/progress handlers will throw if you pass something that's not a function.

Requirements:

• JavaScript enabled on client side