Add tests for ARGV.filter_for_dependencies

Library/Homebrew/test/test_ARGV.rb

@@ -44,4 +44,22 @@ class ARGVTests < Test::Unit::TestCase
     assert !ARGV.switch?('-n')
   end
 
+  def test_filter_for_dependencies_clears_flags
+    ARGV.unshift("--debug")
+    ARGV.filter_for_dependencies do
+      assert ARGV.empty?
+    end
+  end
+
+  def test_filter_for_dependencies_ensures_argv_restored
+    ARGV.expects(:replace).with(ARGV.clone)
+    begin
+      ARGV.filter_for_dependencies { raise Exception }
+    rescue Exception
+    end
+  end
+
+  def test_filter_for_dependencies_returns_block_value
+    assert_equal 1, ARGV.filter_for_dependencies { 1 }
+  end
 end