Merge pull request #2841 from mistydemeo/formula_assertions_constant

Define a custom assertion failure error for cross-version compat

Library/Homebrew/dev-cmd/test.rb

@@ -83,7 +83,7 @@ module Homebrew
             exec(*args)
           end
         end
-      rescue MiniTest::Assertion => e
+      rescue ::Test::Unit::AssertionFailedError => e
         ofail "#{f.full_name}: failed"
         puts e.message
       rescue Exception => e

Library/Homebrew/formula_assertions.rb

@@ -3,6 +3,11 @@ module Homebrew
     require "test/unit/assertions"
     include ::Test::Unit::Assertions
 
+    # TODO: remove this when we no longer support Ruby 2.0.
+    unless defined?(Test::Unit::AssertionFailedError)
+      Test::Unit::AssertionFailedError = MiniTest::Assertion
+    end
+
     # Returns the output of running cmd, and asserts the exit status
     def shell_output(cmd, result = 0)
       ohai cmd