Improve python tests for brew bots

Allow `build.with?` and similar methods to be used during the test
phase. The BuildOptions (`build`) are initialized with the
`Tab.used_options` unless explicitly overwritten on the command line.

So basically `build.with?` works in `def install` and in `test do` as
one would naively expect. (For the test, gramatically it should be
`built.with?` but who cares)

If a formula was installed `--with-python`, now the tests are also
run `--with-python`. This enables us to use the `python do ... end` in
a meaningful manner.

Using `python do ... end` blocks for the tests, because the bot.brew.sh has
system python per default and we need to set the PYTHONPATH for the test.
Potentially to different values for Python 2.x and 3.x.

1 files changed, 3 insertions, 3 deletions

diff --git a/Library/Homebrew/python_helper.rb b/Library/Homebrew/python_helper.rb
index 8ebf0b794..bace441fc 100644
--- a/Library/Homebrew/python_helper.rb
+++ b/Library/Homebrew/python_helper.rb
@@ -16,11 +16,11 @@
 def python_helper(options={:allowed_major_versions => [2, 3]}, &block)
   if !block_given? and !@current_python.nil?
     # We are already inside of a `python do ... end` block, so just return
-    # the current_python or false if the version.major is not allowed.
+    # the current_python or nil if the version.major is not allowed.
     if options[:allowed_major_versions].include?(@current_python.version.major)
       return @current_python
     else
-      return false
+      return nil
     end
   end
 
@@ -42,7 +42,7 @@ def python_helper(options={:allowed_major_versions => [2, 3]}, &block)
   end
 
   # Allow to use an else-branch like so: `if python do ... end; else ... end`.
-  return false if filtered_python_reqs.empty?
+  return nil if filtered_python_reqs.empty?
 
   # Sort by version, so the older 2.x will be used first and if no
   # block_given? then 2.x is preferred because it is returned.