Convert brew bundle test to spec.

Library/Homebrew/test/bundle_test.rb

@@ -1,22 +0,0 @@
-require "testing_env"
-
-class IntegrationCommandTestBundle < IntegrationCommandTestCase
-  def test_bundle
-    needs_test_cmd_taps
-    setup_remote_tap("homebrew/bundle")
-    HOMEBREW_REPOSITORY.cd do
-      shutup do
-        system "git", "init"
-        system "git", "commit", "--allow-empty", "-m", "This is a test commit"
-      end
-    end
-
-    mktmpdir do |path|
-      FileUtils.touch "#{path}/Brewfile"
-      Dir.chdir path do
-        assert_equal "The Brewfile's dependencies are satisfied.",
-          cmd("bundle", "check")
-      end
-    end
-  end
-end

Library/Homebrew/test/cmd/bundle_spec.rb

@@ -0,0 +1,24 @@
+describe "brew bundle", :integration_test, :needs_test_cmd_taps do
+  describe "check" do
+    it "checks if a Brewfile's dependencies are satisfied" do
+      setup_remote_tap "homebrew/bundle"
+
+      HOMEBREW_REPOSITORY.cd do
+        shutup do
+          system "git", "init"
+          system "git", "commit", "--allow-empty", "-m", "This is a test commit"
+        end
+      end
+
+      Dir.mktmpdir do |path|
+        FileUtils.touch "#{path}/Brewfile"
+        Dir.chdir path do
+          expect { brew "bundle", "check" }
+            .to output("The Brewfile's dependencies are satisfied.\n").to_stdout
+            .and not_to_output.to_stderr
+            .and be_a_success
+        end
+      end
+    end
+  end
+end