fakefs/README.markdown

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FakeFS
======
Mocha is great. But when your library is all about manipulating the
filesystem, you really want to test the behavior and not the implementation.
If you're mocking and stubbing every call to FileUtils or File, you're
tightly coupling your tests with the implementation.
def test_creates_directory
FileUtils.expects(:mkdir).with("directory").once
Library.add "directory"
end
The above test will break if we decide to use `mkdir_p` in our code. Refactoring
code shouldn't necessitate refactoring tests.
With FakeFS:
def test_creates_directory
Library.add "directory"
assert File.directory?("directory")
end
Woot.
Usage
-----
require 'fakefs'
# That's it.
Don't Fake the FS Immediately
-----------------------------
require 'fakefs/safe'
FakeFS.activate!
# your code
FakeFS.deactivate!
# or
FakeFS do
# your code
end
RSpec
-----------------------------
The above approach works with RSpec as well. In addition you may include
FakeFS::SpecHelpers to turn FakeFS on and off in a given example group:
require 'fakefs/spec_helpers'
describe "my spec" do
include FakeFS::SpecHelpers
end
See lib/fakefs/spec_helpers.rb for more info.
How is this different than MockFS?
----------------------------------
FakeFS provides a test suite and works with symlinks. It's also strictly a
test-time dependency: your actual library does not need to use or know about
FakeFS.
Caveats
-------
FakeFS internally uses the `Pathname` and `FileUtils` constants. If you use
these in your app, be certain you're properly requiring them and not counting
on FakeFS' own require.
Speed?
------
<http://gist.github.com/156091>
Installation
------------
### [Gemcutter](http://gemcutter.org/)
$ gem install fakefs
### [Rip](http://hellorip.com)
$ rip install git://github.com/defunkt/fakefs.git
Meta
----
* Code: `git clone git://github.com/defunkt/fakefs.git`
* Home: <http://github.com/defunkt/fakefs>
* Docs: <http://defunkt.github.com/fakefs>
* Bugs: <http://github.com/defunkt/fakefs/issues>
* List: <http://groups.google.com/group/fakefs>
* Test: <http://runcoderun.com/defunkt/fakefs>
* Gems: <http://gemcutter.org/gems/fakefs>
* Boss: Chris Wanstrath :: <http://github.com/defunkt>