Create custom matchers for “valid symlink”.

Library/Homebrew/cask/spec/cask/artifact/binary_spec.rb

@@ -20,7 +20,7 @@ describe Hbc::Artifact::Binary do
     shutup do
       Hbc::Artifact::Binary.new(cask).install_phase
     end
-    expect(FileHelper.valid_alias?(expected_path)).to be true
+    expect(expected_path).to be_a_valid_symlink
   end
 
   it "avoids clobbering an existing binary by linking over it" do
@@ -82,7 +82,7 @@ describe Hbc::Artifact::Binary do
         Hbc::Artifact::Binary.new(cask).install_phase
       end
 
-      expect(FileHelper.valid_alias?(expected_path)).to be true
+      expect(expected_path).to be_a_valid_symlink
     end
   end
 end

Library/Homebrew/cask/spec/spec_helper.rb

@@ -34,4 +34,5 @@ end
 RSpec.configure do |config|
   config.order = :random
   config.include(Test::Helper::Shutup)
+  config.include(FileMatchers)
 end

Library/Homebrew/cask/spec/support/file_helper.rb

-module FileHelper
-  module_function
-
-  def valid_alias?(candidate)
-    return false unless candidate.symlink?
-    candidate.readlink.exist?
-  end
-end

Library/Homebrew/cask/spec/support/file_matchers.rb

+module FileMatchers
+  extend RSpec::Matchers::DSL
+
+  matcher :be_a_valid_symlink do
+    match do |path|
+      path.symlink? && path.readlink.exist?
+    end
+  end
+end

Library/Homebrew/cask/test/cask/artifact/suite_test.rb

@@ -20,7 +20,7 @@ describe Hbc::Artifact::Suite do
     end
 
     target_path.must_be :directory?
-    TestHelper.valid_alias?(target_path).must_equal false
+    TestHelper.valid_symlink?(target_path).must_equal false
     source_path.wont_be :exist?
   end
 

Library/Homebrew/cask/test/test_helper.rb

@@ -58,7 +58,7 @@ class TestHelper
     "file://" + local_binary_path(name)
   end
 
-  def self.valid_alias?(candidate)
+  def self.valid_symlink?(candidate)
     return false unless candidate.symlink?
     candidate.readlink.exist?
   end