add missing test coverage for suite artifact

refs: Homebrew#7382

test/cask/artifact/suite_test.rb

@@ -0,0 +1,48 @@
+require 'test_helper'
+
+describe Cask::Artifact::Suite do
+  let(:cask) {
+    Cask.load('with-suite').tap do |cask|
+      TestHelper.install_without_artifacts(cask)
+    end
+  }
+  let(:expected_path) {
+    Cask.appdir/'caffeine_suite'
+  }
+
+  it "links the suite to the proper directory" do
+    shutup do
+      Cask::Artifact::Suite.new(cask).install_phase
+    end
+
+    TestHelper.valid_alias?(expected_path).must_equal true
+  end
+
+  it "creates a suite containing the expected app" do
+    shutup do
+      Cask::Artifact::Suite.new(cask).install_phase
+    end
+
+    expected_path.join('Caffeine.app').must_be :exist?
+  end
+
+  it "avoids clobbering an existing suite by linking over it" do
+    FileUtils.touch expected_path
+
+    shutup do
+      Cask::Artifact::Suite.new(cask).install_phase
+    end
+
+    expected_path.wont_be :symlink?
+  end
+
+  it "clobbers an existing symlink" do
+    expected_path.make_symlink('/tmp')
+
+    shutup do
+      Cask::Artifact::Suite.new(cask).install_phase
+    end
+
+    File.readlink(expected_path).wont_equal '/tmp'
+  end
+end

test/support/Casks/with-suite.rb

@@ -0,0 +1,9 @@
+class WithSuite < TestCask
+  version '1.2.3'
+  sha256 'd1302a0dc25aff72ad395ed01a830468b92253ffd28269574f3ac0b5eb8aad54'
+
+  url TestHelper.local_binary_url('caffeine_suite.zip')
+  homepage 'http://example.com/with-suite'
+
+  suite 'caffeine_suite'
+end