missing: add tests for not missing and hide

Library/Homebrew/test/test_missing.rb

@@ -1,11 +1,34 @@
 require "helper/integration_command_test_case"
 
 class IntegrationCommandTestMissing < IntegrationCommandTestCase
-  def test_missing
+  def setup
+    super
+
     setup_test_formula "foo"
     setup_test_formula "bar"
+  end
+
+  def make_prefix(name)
+    (HOMEBREW_CELLAR/name/"1.0").mkpath
+  end
+
+  def test_missing_missing
+    make_prefix "bar"
 
-    (HOMEBREW_CELLAR/"bar/1.0").mkpath
     assert_match "foo", cmd("missing")
   end
+
+  def test_missing_not_missing
+    make_prefix "foo"
+    make_prefix "bar"
+
+    assert_empty cmd("missing")
+  end
+
+  def test_missing_hide
+    make_prefix "foo"
+    make_prefix "bar"
+
+    assert_match "foo", cmd("missing", "--hide=foo")
+  end
 end