Convert `os/mac/dependency_collector` test to spec.

Library/Homebrew/test/os/mac/dependency_collector_spec.rb

+require "dependency_collector"
+
+RSpec::Matchers.alias_matcher :need_tar_xz_dependency, :be_tar_needs_xz_dependency
+
+describe DependencyCollector do
+  after(:each) do
+    described_class.clear_cache
+  end
+
+  specify "#tar_needs_xz_dependency?" do
+    allow(MacOS).to receive(:version).and_return(MacOS::Version.new("10.9"))
+    expect(described_class).not_to need_tar_xz_dependency
+  end
+
+  specify "LD64 pre-Leopard dependency" do
+    allow(MacOS).to receive(:version).and_return(MacOS::Version.new("10.4"))
+    expect(subject.build(:ld64)).to eq(LD64Dependency.new)
+  end
+
+  specify "LD64 Leopard or newer dependency" do
+    allow(MacOS).to receive(:version).and_return(MacOS::Version.new("10.5"))
+    expect(subject.build(:ld64)).to be nil
+  end
+
+  specify "ant Mavericks or newer dependency" do
+    allow(MacOS).to receive(:version).and_return(MacOS::Version.new("10.9"))
+    subject.add ant: :build
+    expect(subject.deps.find { |dep| dep.name == "ant" }).to eq(Dependency.new("ant", [:build]))
+  end
+
+  specify "ant pre-Mavericks dependency" do
+    allow(MacOS).to receive(:version).and_return(MacOS::Version.new("10.7"))
+    subject.add ant: :build
+    expect(subject.deps.find { |dep| dep.name == "ant" }).to be nil
+  end
+
+  specify "Resource xz pre-Mavericks dependency" do
+    allow(MacOS).to receive(:version).and_return(MacOS::Version.new("10.8"))
+    resource = Resource.new
+    resource.url("http://example.com/foo.tar.xz")
+    expect(subject.add(resource)).to eq(Dependency.new("xz", [:build]))
+  end
+
+  specify "Resource xz Mavericks or newer dependency" do
+    allow(MacOS).to receive(:version).and_return(MacOS::Version.new("10.9"))
+    resource = Resource.new
+    resource.url("http://example.com/foo.tar.xz")
+    expect(subject.add(resource)).to be nil
+  end
+end

Library/Homebrew/test/os/mac/dependency_collector_test.rb

-require "testing_env"
-require "dependency_collector"
-
-class OSMacDependencyCollectorTests < Homebrew::TestCase
-  def find_dependency(name)
-    @d.deps.find { |dep| dep.name == name }
-  end
-
-  def setup
-    super
-    @d = DependencyCollector.new
-  end
-
-  def teardown
-    DependencyCollector.clear_cache
-    super
-  end
-
-  def test_tar_needs_xz_dependency
-    MacOS.stubs(:version).returns(MacOS::Version.new("10.9"))
-    refute DependencyCollector.tar_needs_xz_dependency?
-  end
-
-  def test_ld64_dep_pre_leopard
-    MacOS.stubs(:version).returns(MacOS::Version.new("10.4"))
-    assert_equal LD64Dependency.new, @d.build(:ld64)
-  end
-
-  def test_ld64_dep_leopard_or_newer
-    MacOS.stubs(:version).returns(MacOS::Version.new("10.5"))
-    assert_nil @d.build(:ld64)
-  end
-
-  def test_ant_dep_mavericks_or_newer
-    MacOS.stubs(:version).returns(MacOS::Version.new("10.9"))
-    @d.add ant: :build
-    assert_equal find_dependency("ant"), Dependency.new("ant", [:build])
-  end
-
-  def test_ant_dep_pre_mavericks
-    MacOS.stubs(:version).returns(MacOS::Version.new("10.7"))
-    @d.add ant: :build
-    assert_nil find_dependency("ant")
-  end
-
-  def test_resource_dep_xz_pre_mavericks
-    MacOS.stubs(:version).returns(MacOS::Version.new("10.8"))
-    resource = Resource.new
-    resource.url("http://example.com/foo.tar.xz")
-    assert_equal Dependency.new("xz", [:build]), @d.add(resource)
-  end
-
-  def test_resource_dep_xz_mavericks_or_newer
-    MacOS.stubs(:version).returns(MacOS::Version.new("10.9"))
-    resource = Resource.new
-    resource.url("http://example.com/foo.tar.xz")
-    assert_nil @d.add(resource)
-  end
-end