testing: add FakeRootSuite

testing: add FakeRootSuite

Use it where appropriate. This fixes various places
where tests were dependent on $HOME containing
an accessible .ssh directory.

https://code.launchpad.net/~rogpeppe/juju-core/141-test-HOME-independence/+merge/134112

Requires: https://code.launchpad.net/~rogpeppe/juju-core/142-jujutest-attrs/+merge/134080

(do not edit description out of merge proposal)

[rog, 2012-11-13 14:41:20]

Please take a look.

[TheMue, 2012-11-13 15:11:47]

Mostly OK, but one comment and one question.

https://codereview.appspot.com/6853043/diff/2001/environs/config_test.go
File environs/config_test.go (right):

https://codereview.appspot.com/6853043/diff/2001/environs/config_test.go#newc...
environs/config_test.go:100: func (s *suite) TestInvalidEnv(c *C) {
Like in line 56 "s" isn't need. But IMHO this here looks better and I would add
an "s" there too. Nevertheless, it's no error.

https://codereview.appspot.com/6853043/diff/2001/juju/testing/conn.go
File juju/testing/conn.go (right):

https://codereview.appspot.com/6853043/diff/2001/juju/testing/conn.go#newcode142
juju/testing/conn.go:142: panic("DataDir called out of test context")
Why that context check here? Seems natural to me that it has to be used in test
context, like others too.

https://codereview.appspot.com/6853043/diff/2001/juju/testing/conn.go#newcode150
juju/testing/conn.go:150: panic("WriteConfig called outside test context")
Dito.

[rog, 2012-11-13 15:35:42]

https://codereview.appspot.com/6853043/diff/2001/juju/testing/conn.go
File juju/testing/conn.go (right):

https://codereview.appspot.com/6853043/diff/2001/juju/testing/conn.go#newcode142
juju/testing/conn.go:142: panic("DataDir called out of test context")
On 2012/11/13 15:11:47, TheMue wrote:
> Why that context check here? Seems natural to me that it has to be used in
test
> context, like others too.

The reason is defensive programming - if this is called out of context, we could
potentially alter the real directory and change important files.

https://codereview.appspot.com/6853043/diff/2001/juju/testing/conn.go#newcode150
juju/testing/conn.go:150: panic("WriteConfig called outside test context")
On 2012/11/13 15:11:47, TheMue wrote:
> Dito.

ditto.

[niemeyer, 2012-11-15 00:28:27]

https://codereview.appspot.com/6853043/diff/2001/juju/conn_test.go
File juju/conn_test.go (right):

https://codereview.appspot.com/6853043/diff/2001/juju/conn_test.go#newcode31
juju/conn_test.go:31: cs.FakeRootSuite.SetUpTest(c)
As we discussed on IRC, the whole is getting deeper, and there isn't a clear
benefit. None of the tests below needed the fake root, and now we're adding more
harness, and more logic, just because we can.