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