add more test

Closes #514.

Signed-off-by: Xu Cheng <xucheng@me.com>

Library/Homebrew/test/test_formulary.rb

@@ -90,12 +90,17 @@ class FormularyFactoryTest < Homebrew::TestCase
     alias_dir.rmtree
   end
 
-  def test_factory_from_rack
+  def test_factory_from_rack_and_from_keg
     formula = Formulary.factory(@path)
     installer = FormulaInstaller.new(formula)
     shutup { installer.install }
     keg = Keg.new(formula.prefix)
-    assert_kind_of Formula, Formulary.from_rack(formula.rack)
+    f = Formulary.from_rack(formula.rack)
+    assert_kind_of Formula, f
+    assert_kind_of Tab, f.build
+    f = Formulary.from_keg(keg)
+    assert_kind_of Formula, f
+    assert_kind_of Tab, f.build
   ensure
     keg.unlink
     keg.uninstall

Library/Homebrew/test/test_tab.rb

@@ -29,6 +29,9 @@ class TabTests < Homebrew::TestCase
     assert_empty tab.used_options
     refute_predicate tab, :built_as_bottle
     refute_predicate tab, :poured_from_bottle
+    assert_predicate tab, :stable?
+    refute_predicate tab, :devel?
+    refute_predicate tab, :head?
     assert_nil tab.tap
     assert_nil tab.time
     assert_nil tab.HEAD
@@ -74,6 +77,9 @@ class TabTests < Homebrew::TestCase
     assert_equal @unused.sort, tab.unused_options.sort
     refute_predicate tab, :built_as_bottle
     assert_predicate tab, :poured_from_bottle
+    assert_predicate tab, :stable?
+    refute_predicate tab, :devel?
+    refute_predicate tab, :head?
     assert_equal "homebrew/core", tab.tap.name
     assert_equal :stable, tab.spec
     refute_nil tab.time
@@ -90,6 +96,9 @@ class TabTests < Homebrew::TestCase
     assert_equal @unused.sort, tab.unused_options.sort
     refute_predicate tab, :built_as_bottle
     assert_predicate tab, :poured_from_bottle
+    assert_predicate tab, :stable?
+    refute_predicate tab, :devel?
+    refute_predicate tab, :head?
     assert_equal "homebrew/core", tab.tap.name
     assert_equal :stable, tab.spec
     refute_nil tab.time