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.

13 files changed, 66 insertions, 46 deletions

diff --git a/Library/Formula/enchant.rb b/Library/Formula/enchant.rb
index 2d331c8e0..2a99f0571 100644
--- a/Library/Formula/enchant.rb
+++ b/Library/Formula/enchant.rb
@@ -21,28 +21,24 @@ class Enchant < Formula
                           "--prefix=#{prefix}",
                           "--disable-ispell",
                           "--disable-myspell"
-    system "make install"
+    system "make", "install"
 
-    if build.with? 'python'
+    python do
       # Now we handle the python bindings from the subformulae PyEnchant
       PyEnchant.new.brew do
         # Don't download and install distribute now
         inreplace 'setup.py', "distribute_setup.use_setuptools()", ""
-        python do
           ENV['PYENCHANT_LIBRARY_PATH'] = lib/'libenchant.dylib'
           system python, 'setup.py', 'install', "--prefix=#{prefix}",
                                 '--single-version-externally-managed',
                                 '--record=installed.txt'
-        end
       end
     end
   end
 
-  def test
-    if build.with? 'python'
-      python do
-        system python, "-c", "import enchant; d=enchant.Dict('en_US'); print(d.suggest('homebrew'))"
-      end
+  test do
+    python do
+      system python, "-c", "import enchant; d=enchant.Dict('en_US'); print(d.suggest('homebrew'))"
     end
   end
 end
diff --git a/Library/Formula/fontforge.rb b/Library/Formula/fontforge.rb
index bb8d9b7fe..dbe0688fe 100644
--- a/Library/Formula/fontforge.rb
+++ b/Library/Formula/fontforge.rb
@@ -85,12 +85,10 @@ class Fontforge < Formula
     system "make install"
   end
 
-  def test
+  test do
     system "#{bin}/fontforge", "-version"
-    if build.with? 'python'
-      python do
-        system python, "-c", "import fontforge"
-      end
+    python do
+      system python, "-c", "import fontforge"
     end
   end
 
diff --git a/Library/Formula/libvirt.rb b/Library/Formula/libvirt.rb
index 6b88d28a2..f47bb0b7e 100644
--- a/Library/Formula/libvirt.rb
+++ b/Library/Formula/libvirt.rb
@@ -63,12 +63,10 @@ class Libvirt < Formula
   end
 
   test do
-    if build.with? 'python'
-      python do
-        # Testing to import the mod because that is a .so file where linking
-        # can break.
-        system python, '-c', "import libvirtmod"
-      end
+    python do
+      # Testing to import the mod because that is a .so file where linking
+      # can break.
+      system python, '-c', "import libvirtmod"
     end
   end
 end
diff --git a/Library/Formula/libxml2.rb b/Library/Formula/libxml2.rb
index ff762f22e..f78d0a1c0 100644
--- a/Library/Formula/libxml2.rb
+++ b/Library/Formula/libxml2.rb
@@ -75,11 +75,8 @@ class Libxml2 < Formula
   end
 
   test do
-    if build.with? 'python'
+    python do
       system python, '-c', "import libxml2"
-    else
-      puts "No tests because built --without-python."
-      true
     end
   end
 end
diff --git a/Library/Formula/omniorb.rb b/Library/Formula/omniorb.rb
index 813da8ec3..a9b2a196e 100644
--- a/Library/Formula/omniorb.rb
+++ b/Library/Formula/omniorb.rb
@@ -38,8 +38,7 @@ class Omniorb < Formula
 
   test do
     system "#{bin}/omniidl", "-h"
-
-    if build.with? 'python'
+    python do
       system python, "-c", %(import omniORB; print 'omniORBpy', omniORB.__version__)
     end
   end
diff --git a/Library/Formula/portmidi.rb b/Library/Formula/portmidi.rb
index d24661f06..ccecfd766 100644
--- a/Library/Formula/portmidi.rb
+++ b/Library/Formula/portmidi.rb
@@ -43,8 +43,8 @@ class Portmidi < Formula
   end
 
   test do
-    if build.with?('python') || Tab.for_name('portmidi').with?('python')
-      system "python", "-c", "import pyportmidi; pyportmidi.init()"
+    python do
+      system python, "-c", "import pyportmidi; pyportmidi.init()"
     end
   end
 
diff --git a/Library/Formula/pygtkglext.rb b/Library/Formula/pygtkglext.rb
index 92e583bf8..326af30da 100644
--- a/Library/Formula/pygtkglext.rb
+++ b/Library/Formula/pygtkglext.rb
@@ -23,6 +23,8 @@ class Pygtkglext < Formula
   end
 
   test do
-    system "python", "-c", "import pygtk", "pygtk.require('2.0')", "import gtk.gtkgl"
+    python do
+      system python, "-c", "import pygtk", "pygtk.require('2.0')", "import gtk.gtkgl"
+    end
   end
 end
diff --git a/Library/Formula/pygtksourceview.rb b/Library/Formula/pygtksourceview.rb
index 485df897f..fe8de6245 100644
--- a/Library/Formula/pygtksourceview.rb
+++ b/Library/Formula/pygtksourceview.rb
@@ -22,6 +22,8 @@ class Pygtksourceview < Formula
   end
 
   test do
-    system "python", "-c", "import gtksourceview2"
+    python do
+      system python, "-c", "import gtksourceview2"
+    end
   end
 end
diff --git a/Library/Formula/shiboken.rb b/Library/Formula/shiboken.rb
index fe01e19b9..171a666a2 100644
--- a/Library/Formula/shiboken.rb
+++ b/Library/Formula/shiboken.rb
@@ -49,10 +49,8 @@ class Shiboken < Formula
   end
 
   test do
-    if build.with? 'python'
-      python do
-        system python, "-c", "import shiboken"
-      end
+    python do
+      system python, "-c", "import shiboken"
     end
   end
 end
diff --git a/Library/Homebrew/build_options.rb b/Library/Homebrew/build_options.rb
index 0cd3a5a46..441a81bc2 100644
--- a/Library/Homebrew/build_options.rb
+++ b/Library/Homebrew/build_options.rb
@@ -100,13 +100,26 @@ class BuildOptions
   # implicit_options are needed because `depends_on 'spam' => 'with-stuff'`
   # complains if 'spam' has stuff as default and only defines `--without-stuff`.
   def implicit_options
-    implicit = unused_options.map do |o|
-      if o.name =~ /^with-(.+)$/ && without?($1)
-        Option.new("without-#{$1}")  # we lose the description, but that's ok
-      elsif o.name =~ /^without-(.+)$/ && with?($1)
-        Option.new("with-#{$1}")
-      end
+    implicit = unused_options.map do |option|
+      opposite_of option unless has_opposite_of? option
     end.compact
     Options.new(implicit)
   end
+
+  def has_opposite_of? option
+    true if args.include? opposite_of option
+  end
+
+  def opposite_of option
+    option = Option.new option
+    if option.name =~ /^with-(.+)$/
+      Option.new("without-#{$1}")
+    elsif option.name =~ /^without-(.+)$/
+      Option.new("with-#{$1}")
+    elsif option.name =~ /^enable-(.+)$/
+      Option.new("disable-#{$1}")
+    elsif option.name =~ /^disable-(.+)$/
+      Option.new("enable-#{$1}")
+    end
+  end
 end
diff --git a/Library/Homebrew/formula.rb b/Library/Homebrew/formula.rb
index 39bea8ee6..e5b071c0f 100644
--- a/Library/Homebrew/formula.rb
+++ b/Library/Homebrew/formula.rb
@@ -515,6 +515,9 @@ class Formula
   def test
     require 'test/unit/assertions'
     extend(Test::Unit::Assertions)
+    # Adding the used options allows us to use `build.with?` inside of tests
+    tab = Tab.for_name(name)
+    tab.used_options.each { |opt| build.args << opt unless build.has_opposite_of? opt }
     ret = nil
     mktemp do
       @testpath = Pathname.pwd
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.
diff --git a/Library/Homebrew/test/test_build_options.rb b/Library/Homebrew/test/test_build_options.rb
index cc5fd01d7..9e2a9e06f 100644
--- a/Library/Homebrew/test/test_build_options.rb
+++ b/Library/Homebrew/test/test_build_options.rb
@@ -1,9 +1,9 @@
-require 'testing_env'
+  require 'testing_env'
 require 'build_options'
 
 class BuildOptionsTests < Test::Unit::TestCase
   def setup
-    args = %w{--with-foo --with-bar --without-qux}
+    args = %w{--with-foo --with-bar --without-qux} # args fake the command line
     @build = BuildOptions.new(args)
     @build.add("with-foo")
     @build.add("with-bar")
@@ -44,7 +44,7 @@ class BuildOptionsTests < Test::Unit::TestCase
   end
 
   def test_implicit_options
-    # --without-baz is not explicitly specified on the command line
+    # --without-baz is not explicitly specified on the command line (i.e. args)
     # therefore --with-baz should be implicitly assumed:
     assert @build.implicit_options.include?("--with-baz")
     # But all these should not be in the implict_options:
@@ -53,4 +53,18 @@ class BuildOptionsTests < Test::Unit::TestCase
     assert !@build.implicit_options.include?("--without-bar")
     assert !@build.implicit_options.include?("--with-qux")
   end
+
+  def test_opposite_of
+    assert @build.opposite_of(Option.new("with-foo")) == Option.new("without-foo")
+    assert @build.opposite_of("without-foo") == Option.new("with-foo")
+    assert @build.opposite_of(Option.new("enable-spam")) == Option.new("disable-spam")
+    assert @build.opposite_of("disable-beer") == Option.new("enable-beer")
+  end
+
+  def test_has_opposite_of?
+    assert @build.has_opposite_of?("--without-foo")
+    assert @build.has_opposite_of?(Option.new("--with-qux"))
+    assert !@build.has_opposite_of?("--without-qux")
+    assert !@build.has_opposite_of?("--without-nonexisting")
+  end
 end