This is a pre-release version of Immutable.js. Please try it at your own risk and report any issues you encounter so an official release can be shipped with great confidence.

As a pre-release, this changelog doesn't contain everything that has changed. Take a look at the commit log for a complete view, and expect a more thorough changelog for the official release.

Breaking Changes

• The Iterable class has been renamed to Collection, and isIterable() has been renamed to isCollection(). Aliases with the existing names exist to make transitioning code easier.

• The "predicate" functions, isCollection, isKeyed, isIndexed, isAssociative have been moved from Iterable. to the top level exports.

• Record is no longer an Immutable Collection type.

  • Now isCollection(myRecord) returns false instead of true.
  • The sequence API (such as map, filter, forEach) no longer exist on Records.
  • delete() and clear() no longer exist on Records.

• The toJSON() method is now a shallow conversion (previously it was an alias for toJS(), which remains a deep conversion).

• Some minor implementation details have changed, which may require updates to libraries which deeply integrate with Immutable.js's private APIs.

• The Cursor API is officially deprecated. Use immutable-cursor instead.

New Stuff!

• A new predicate function isValueObject() helps to detect objects which implement equals() and hashCode(), and type definitions now define the interface ValueObject which you can implement in your own code to create objects which behave as values and can be keys in Maps or entries in Sets.

• The Flowtype and TypeScript type definitions have been completely rewritten with much higher quality and accuracy, taking advantage of the latest features from both amazing tools.

• Using fromJS() with a "reviver" function now provides access to the key path to each translated value. (#1118)

Bug fixes

• Numerous bug fixes have gone into this release.