pivotal/jasmine — pull request #272 by dsuket (2012-08-17 06:02:03+00:00)
Title: Custom error message of Matcher

Usage:
```
var failMessage = 'obj.selected is not true. obj.id = ' + obj.id;
expect(obj.selected, failMessage).toBe(true)
```
By default, when obj.selected is false, "Expected false to be true" is printed. if you needs more information when test fail, that can show custom message.
I know get same effect to add message function to matcher object. but that is prolixity.