deps: Add tests for CaskDependent

Library/Homebrew/cask_dependent.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # An adapter for casks to provide dependency information in a formula-like interface
 class CaskDependent
   def initialize(cask)

Library/Homebrew/test/cask_dependent_spec.rb

@@ -0,0 +1,63 @@
+# frozen_string_literal: true
+
+require "cask/cask_loader"
+require "cask_dependent"
+
+describe CaskDependent, :needs_macos do
+  subject(:dependent) { described_class.new test_cask }
+
+  let :test_cask do
+    Cask::CaskLoader.load(+<<-RUBY)
+      cask "testing" do
+        depends_on formula: "baz"
+        depends_on cask: "foo-cask"
+        depends_on macos: ">= :mojave"
+        depends_on x11: true
+      end
+    RUBY
+  end
+
+  describe "#deps" do
+    it "is the formula dependencies of the cask" do
+      expect(dependent.deps.map(&:name))
+        .to eq %w[baz]
+    end
+  end
+
+  describe "#requirements" do
+    it "is the requirements of the cask" do
+      expect(dependent.requirements.map(&:name))
+        .to eq %w[foo-cask macos x11]
+    end
+  end
+
+  describe "#recursive_dependencies", :integration_test do
+    it "is all the dependencies of the cask" do
+      setup_test_formula "foo"
+      setup_test_formula "bar"
+      setup_test_formula "baz", <<-RUBY
+        url "https://brew.sh/baz-1.0"
+        depends_on "bar"
+        depends_on :osxfuse
+      RUBY
+
+      expect(dependent.recursive_dependencies.map(&:name))
+        .to eq(%w[foo bar baz])
+    end
+  end
+
+  describe "#recursive_requirements", :integration_test do
+    it "is all the dependencies of the cask" do
+      setup_test_formula "foo"
+      setup_test_formula "bar"
+      setup_test_formula "baz", <<-RUBY
+        url "https://brew.sh/baz-1.0"
+        depends_on "bar"
+        depends_on :osxfuse
+      RUBY
+
+      expect(dependent.recursive_requirements.map(&:name))
+        .to eq(%w[foo-cask macos x11 osxfuse])
+    end
+  end
+end