How to write tests for missing ''require'' in the Rails core?

Jeroen van Dijk
Sat, 27 Feb 2010 19:49:14 -0000

When hacking on rails 3 I have discovered some missing requires. For
example, when I wanted to use ActionDispatch::Integration::Session, it
get an error because Test::Unit::Assertions is used but ''test/unit/
assertions'' is not required.

So I have tried to build a patch for this situation. Well actually,
the creation of the patch is simple, but how do you test (with test/
unit) that we can use this class without requiring its dependency
''test/unit/assertions''? To have a real test case I would need
an
isolated environment which would require the class, but would not
require any other dependency. One thing that is hard, is that the
rails test suite itself already loads a lot of necessary dependencies
which would make it hard to write a failing test for these cases (see
''abstract_unit''  in actionpack/lib/test).

Anyhow, when I wrote a first test case I got a chain of dependency
issues so I think it is worth to investigate this, but I can''t really
think of a way to include it in the current test suite.

Any suggestions?

Jeroen