Since the MakePluginDir function takes the TestSuite as receiver, we
don't need to additionally pass in a reference to testing.T, since the
test suite already contains one instance, and offers a function to get
it from.
The PluginVersionConfig structure was first introduced when building
the early versions of the test package, but it was an unnecessary
abstraction over go-version.Version.
So we remove that structure definition, and instead we directly use the
version for building those temporary plugins.
The CopyFile function is essentially a go recreation of the `cp'
command, which copies one file from a source path to a destination
directory or file.
This can be used for several tests in the future.
When creating a temporary plugin directory, we had to build a cleanup
function, which could be as simple as `os.Mkdirall` without any kind of
warning that a directory failed to be cleaned-up, or we could do some
more work in order to report the possible issues around this.
That code would quickly be redundant, as there's not a ton of
variability in the code that can be written for this step, so we
abstract it through a pre-defined cancellation function which can be
safely defer invoked.
Acceptance testing, i.e. running Packer core commands in a controlled
environment and ensuring the behaviour is consistent to what we
expect/document, is not something we have a robust and usable framework
for at the moment.
This commit is a proposal for a base testing framework of the sort, that
is meant to be shipped with packer core, and which will eventually host
most of the tests we currently do in command where we mock an
environment.
Lucas Bajolet