Add fixtures to aruba

[ghost]

This PR adds the basics to support fixtures in aruba. Also see #219.

Things to discuss:

• Use of OpenStruct

  I used OpenStruct here to make both paths of a fixture available: The relative one which is used to find a fixture and the absolute one, which can be used by a consumer of the api like copy_file. I can replace this by a Hash if this is preferred. Though OpenStruct is part of ruby core distribution.

• Use of Pathname

  I like the relative_path_from-functionality of Pathname. It makes the intention of the author clear and is quite easy to use to build relative paths.

• Use of %/ as fixture path prefix

  It does not have a special meaning in ruby so far - besides percent classes which are not followed by /.

• Order of directories to be searched

  I use "my" preferred order here, but I'm open to change it.

• Commit Style

  I will refactor the "commits" after all things above are discussed to make sure that there's one commit for the tests and one commit for the implementation.

• Rubocop

  I think we will need to "guard" this line and that line here because of === (3x =). But === returns true'/falsefor bothStringANDRegexpand thus is more flexible than==`

[ghost]

Any comments about this one @jarl-dk ?

[ghost]

@jarl-dk ping... 😄

[maxmeyer]

This PR has been opened for a while.

@aslakhellesoy @mattwynne @jarl-dk Is there anyone willing to review this? I'm a bit frustrated waiting so long for feedback.

[mattwynne]

I don't understand what a fixture is in this context. Is there an example somewhere of how this feature would be used in practice? Maybe add something to the README?

[ghost]

This PR is a result of the discussion in #219.

I added an example to the readme. Though I must admit, that this PR only adds some more basic stuff which will become really useful when #219 (Add copy method) is finished and makes use of this. Until then the example in the readme feels a little bit unfinished.

[jarl-dk]

I'll take a look soon.

[jarl-dk]

@mattwynne : In this context a fixture is a constant byte sequence (stored as a file). Such fixture files are sometimes used to compare binary data against. It could be images or other binary static data that you verify against in a test. e.g.
check_binary_file_content('produced_file.jpeg','fixtures/expected_file_content.jpeg')
such fixtures are often stored in spec/fixtures, features/fixtures, or test/fixtures.
Does it make sense?

[mattwynne]

OK, understood. Thanks for the explanation.

[jarl-dk]

@mattwynne : As you can imagine the example
check_binary_file_content('produced_file.jpeg','fixtures/expected_file_content.jpeg') will not really work because fixtures are stored in spec/fixtures, features/fixtures, or test/fixtures and the above file paths (especially) the second parameter are relative to current working directory which is a new directory in every run (under tmp/aruba. So the purpose of this PR is to introduce a special character (just like ~ for HOME) that expands to the directory with fixtures. This specific PR proposes to use % for that turning the example into check_binary_file_content('produced_file.jpeg','%/expected_file_content.jpeg'), but other characters have been proposed (such as -, |, ^, >) starting at #219 (comment)
Personally I prefer a single character and |, <, and > may be confused with shell piping.

[jarl-dk]

Actually I have often used fixtures (images) to test web-applications using cucumber. So in some sense I see the fixture expansion feature (the purpose of this PR) to be more generally useful than just for CLI testing. So someday I see this feature being implemented in a more general ruby gem (cucumber or even better: mini-test). But maybe we should just start here in Aruba to demonstrate proof-of-concept.

[jarl-dk]

Making aruba root directory configurable is not related to this PR (as I see it). I suggest you take that out in a seperate PR.

[ghost]

I see, but it makes the configuration of the fixtures more cleaner. I added a new PR for this. Would you mind to merge it first, then?

[ghost]

I cleaned up the implementation and rebased it on master... BTW I left the root_directory-implementation within this PR, but opened a new PR #232 for adding it. I will rebase this PR when/if #232 is merged.

[jarl-dk]

I was a bit fast on criticising absolute_path. I see that it was already part of v0.6.2.

I am glad that you take the time to rename it and make absolute_path deprecated.

[jarl-dk]

Looks like copy paste code from chmod

[ghost]

ups again. Will be fixed...

[ghost]

@jarl-dk Fixed.

[ghost]

rebased with master. waiting for #232 to be merged and then I will rebase again.

[ghost]

@jarl-dk @mattwynne Anything missing here? Would love to see this merged soon. Please be aware that this PR includes code from #232. So it makes sense to merge #232 first.

[jarl-dk]

I have rework abit, @dg-ratiodata Please review my rework. Still I think this feature is not exploited in feature tests where I think it belongs most. Basically the new Aruba#expand_path should be used everywhere in lib/aruba/cucumber.rb so the fixtures file path can be used in feature steps. So some more work is needed there...