[Rubygems-developers] The path to Environmentally Clean Test

[Chad Fowler]

On 12/4/2004, at 9:38 PM, Jim Weirich wrote:

> I feel like the EPA, espousing environmental protection and all that 
> :-)
>
> I'm working on getting the tests to run cleanly without referencing 
> the normal desktop environment.  This is important because (a) we want 
> the tests to test what is in the working directory, not the installed 
> version of RubyGems, and (b) when you have dependencies on the 
> environment, the tests will run differently on different machines.
>
> So, here's a quick summary of the changes I just committed.
>
> (1) The rake file used to use a library function to run the tests. 
> Since Rake can be a gem, it may need to run require_gem to get to its 
> library.  Unfortunately require_gem is what we are testing, so we 
> can't depend upon it working.  So I moved the rake library function to 
> a scripts directory and updated the Rakefile to run the tests 
> "inline". Thus, better separation between test and environment.
>
> (NOTE:  Normally Rake runs in its own Ruby "VM" and there is no 
> problem.  In the unit tests, the library code (using the installed 
> gem) needed to be loaded in the same VM as the test code (using the 
> non-installed VM).  Did that make sense?)
>
> (2) The next big environment dependency are the gem directories where 
> stuff is installed.  This is controlled by Gem.dir and $GEM_PATH and 
> are calculated at load time (well, $GEM_PATH at least).  I changed 
> $GEM_PATH to Gem.path everywhere in the code, and made both calculated 
> upon demand.  I also added a GEM_HOME environment variable.
>
> Gem.dir is the directory where installs will take place.  There is a 
> default value (in the ruby dist directory), but if you give a value 
> for GEM_PATH, it will be used instead.  This allows our tests to 
> target installs into temp directories without messing up installed 
> stuff.
>
> Gem.path is a list of gem directories to search for gems.  It should 
> include Gem.dir (usually as the last entry).  If you set the RUBY_GEMS 
> environment variable with a path-style list, this list will be used 
> for Gem.path.  The Gem.dir directory will be appended to the list if 
> it is not already there.
>
> Tests have been added for Gem.dir/Gem.path.  If this behavior doesn't 
> make sense, we can easily change it.
>
> Oh, Gem.clear_paths and Gem.use_paths are provided for making testing 
> easier.  Gem.clear_paths clears the Gem.dir and Gem.path values so 
> that the next time they are needed they will be recalculated from 
> scratch. Gem.use_path(home, path_list) allows us to set the Gem.dir 
> and Gem.path values directly in a unit test without mucking around 
> with environment variables.
>

This all looks great to me.  I just made a change on the wiki docs to 
reflect Gem.path vs. $GEM_PATH.

> This is just the start to enable Environment clean testing.  We need 
> to start using them now.  At least *two* tests are still 
> environmentally sensitive because they were failing until I installed 
> the latest CVS, then they started passing (they were remote installer 
> related).
>

I'll add this to my list, though it may be tomorrow night before I can 
get to it.  Feel free to fix it before then if you're motivated. :)

> Finally, just one more thing.
>
> For some reason 'assert_raise' doesn't work on my system, but 
> 'assert_raises' does.  Is the is Test::Unit compatibility thing?  I'm 
> not sure.
>

This was changed on Jan. 9.  I'm working from ruby 1.9, so it's my 
fault that we have assert_raise.  What do you think we should do?  It 
would be nice to test on both 1.8.1 and 1.9.*.

Chad