testing/checkers: more informative DeepEquals

testing/checkers: more informative DeepEquals

I have spent too long delving into the output of gc.DeepEquals
results looking for differences. This changes jc.DeepEquals
to say what you want to know.

Trivial example:

	c.Assert([]int{1,3,5}, jc.DeepEquals, []int{1,3,7})

produces:

	tst_test.go:17:
	    c.Assert([]int{1, 3, 5}, jc.DeepEquals, []int{1, 3, 7})
	... obtained []int = []int{1, 3, 5}
	... expected []int = []int{1, 3, 7}
	... mismatch at [2]: unequal; obtained 5; expected 7

https://code.launchpad.net/~rogpeppe/juju-core/481-testing-deepequals/+merge/201432

(do not edit description out of merge proposal)

[rog, 2014-01-13 15:13:39]

Please take a look.

[dimitern, 2014-01-13 15:28:04]

Excellent! LGTM with a minor grumble about more expressive tests.

https://codereview.appspot.com/51480043/diff/20001/testing/checkers/bool_test.go
File testing/checkers/bool_test.go (right):

https://codereview.appspot.com/51480043/diff/20001/testing/checkers/bool_test...
testing/checkers/bool_test.go:110: func (s *BoolSuite) TestDeepEquals(c *gc.C) {
I'd like to see a couple of tests that illustrate the differences between
jc.DeepEquals and gc.DeepEquals (like in the description).

[rog, 2014-01-13 16:06:15]

Please take a look.

[rog, 2014-01-13 16:09:14]

https://codereview.appspot.com/51480043/diff/20001/testing/checkers/bool_test.go
File testing/checkers/bool_test.go (right):

https://codereview.appspot.com/51480043/diff/20001/testing/checkers/bool_test...
testing/checkers/bool_test.go:110: func (s *BoolSuite) TestDeepEquals(c *gc.C) {
On 2014/01/13 15:28:04, dimitern wrote:
> I'd like to see a couple of tests that illustrate the differences between
> jc.DeepEquals and gc.DeepEquals (like in the description).

Done.