diff --git a/Library/Homebrew/test/download_strategies_spec.rb b/Library/Homebrew/test/download_strategies_spec.rb
new file mode 100644
index 0000000000..f466b97f4a
--- /dev/null
+++ b/Library/Homebrew/test/download_strategies_spec.rb
@@ -0,0 +1,232 @@
+require "download_strategy"
+
+describe AbstractDownloadStrategy do
+  subject { described_class.new(name, resource) }
+  let(:name) { "foo" }
+  let(:url) { "http://example.com/foo.tar.gz" }
+  let(:resource) { double(Resource, url: url, mirrors: [], specs: {}, version: nil) }
+  let(:args) { %w[foo bar baz] }
+
+  describe "#expand_safe_system_args" do
+    it "works with an explicit quiet flag" do
+      args << { quiet_flag: "--flag" }
+      expanded_args = subject.expand_safe_system_args(args)
+      expect(expanded_args).to eq(%w[foo bar baz --flag])
+    end
+
+    it "adds an implicit quiet flag" do
+      expanded_args = subject.expand_safe_system_args(args)
+      expect(expanded_args).to eq(%w[foo bar -q baz])
+    end
+
+    it "does not mutate the arguments" do
+      result = subject.expand_safe_system_args(args)
+      expect(args).to eq(%w[foo bar baz])
+      expect(result).not_to be args
+    end
+  end
+
+  specify "#source_modified_time" do
+    FileUtils.mktemp "mtime" do
+      FileUtils.touch "foo", mtime: Time.now - 10
+      FileUtils.touch "bar", mtime: Time.now - 100
+      FileUtils.ln_s "not-exist", "baz"
+      expect(subject.source_modified_time).to eq(File.mtime("foo"))
+    end
+  end
+end
+
+describe VCSDownloadStrategy do
+  let(:url) { "http://example.com/bar" }
+  let(:resource) { double(Resource, url: url, mirrors: [], specs: {}, version: nil) }
+
+  describe "#cached_location" do
+    it "returns the path of the cached resource" do
+      allow_any_instance_of(described_class).to receive(:cache_tag).and_return("foo")
+      downloader = described_class.new("baz", resource)
+      expect(downloader.cached_location).to eq(HOMEBREW_CACHE/"baz--foo")
+    end
+  end
+end
+
+describe GitHubPrivateRepositoryDownloadStrategy do
+  subject { described_class.new("foo", resource) }
+  let(:url) { "https://github.com/owner/repo/archive/1.1.5.tar.gz" }
+  let(:resource) { double(Resource, url: url, mirrors: [], specs: {}, version: nil) }
+
+  before(:each) do
+    ENV["HOMEBREW_GITHUB_API_TOKEN"] = "token"
+    allow(GitHub).to receive(:repository).and_return({})
+  end
+
+  it "sets the @github_token instance variable" do
+    expect(subject.instance_variable_get(:@github_token)).to eq("token")
+  end
+
+  it "parses the URL and sets the corresponding instance variables" do
+    expect(subject.instance_variable_get(:@owner)).to eq("owner")
+    expect(subject.instance_variable_get(:@repo)).to eq("repo")
+    expect(subject.instance_variable_get(:@filepath)).to eq("archive/1.1.5.tar.gz")
+  end
+
+  its(:download_url) { is_expected.to eq("https://token@github.com/owner/repo/archive/1.1.5.tar.gz") }
+end
+
+describe GitHubPrivateRepositoryReleaseDownloadStrategy do
+  subject { described_class.new("foo", resource) }
+  let(:url) { "https://github.com/owner/repo/releases/download/tag/foo_v0.1.0_darwin_amd64.tar.gz" }
+  let(:resource) { double(Resource, url: url, mirrors: [], specs: {}, version: nil) }
+
+  before(:each) do
+    ENV["HOMEBREW_GITHUB_API_TOKEN"] = "token"
+    allow(GitHub).to receive(:repository).and_return({})
+  end
+
+  it "parses the URL and sets the corresponding instance variables" do
+    expect(subject.instance_variable_get(:@owner)).to eq("owner")
+    expect(subject.instance_variable_get(:@repo)).to eq("repo")
+    expect(subject.instance_variable_get(:@tag)).to eq("tag")
+    expect(subject.instance_variable_get(:@filename)).to eq("foo_v0.1.0_darwin_amd64.tar.gz")
+  end
+
+  describe "#download_url" do
+    it "returns the download URL for a given resource" do
+      allow(subject).to receive(:resolve_asset_id).and_return(456)
+      expect(subject.download_url).to eq("https://token@api.github.com/repos/owner/repo/releases/assets/456")
+    end
+  end
+
+  specify "#resolve_asset_id" do
+    release_metadata = {
+      "assets" => [
+        {
+          "id" => 123,
+          "name" => "foo_v0.1.0_linux_amd64.tar.gz",
+        },
+        {
+          "id" => 456,
+          "name" => "foo_v0.1.0_darwin_amd64.tar.gz",
+        },
+      ],
+    }
+    allow(subject).to receive(:fetch_release_metadata).and_return(release_metadata)
+    expect(subject.send(:resolve_asset_id)).to eq(456)
+  end
+
+  describe "#fetch_release_metadata" do
+    it "fetches release metadata from GitHub" do
+      expected_release_url = "https://api.github.com/repos/owner/repo/releases/tags/tag"
+      expect(GitHub).to receive(:open).with(expected_release_url).and_return({})
+      subject.send(:fetch_release_metadata)
+    end
+  end
+end
+
+describe GitHubGitDownloadStrategy do
+  subject { described_class.new(name, resource) }
+  let(:name) { "brew" }
+  let(:url) { "https://github.com/homebrew/brew.git" }
+  let(:resource) { double(Resource, url: url, mirrors: [], specs: {}, version: nil) }
+
+  it "parses the URL and sets the corresponding instance variables" do
+    expect(subject.instance_variable_get(:@user)).to eq("homebrew")
+    expect(subject.instance_variable_get(:@repo)).to eq("brew")
+  end
+end
+
+describe GitDownloadStrategy do
+  subject { described_class.new(name, resource) }
+  let(:name) { "baz" }
+  let(:url) { "https://github.com/homebrew/foo" }
+  let(:resource) { double(Resource, url: url, mirrors: [], specs: {}, version: nil) }
+  let(:cached_location) { subject.cached_location }
+
+  before(:each) do
+    @commit_id = 1
+    FileUtils.mkpath cached_location
+  end
+
+  def git_commit_all
+    shutup do
+      system "git", "add", "--all"
+      system "git", "commit", "-m", "commit number #{@commit_id}"
+      @commit_id += 1
+    end
+  end
+
+  def setup_git_repo
+    shutup do
+      system "git", "init"
+      system "git", "remote", "add", "origin", "https://github.com/Homebrew/homebrew-foo"
+    end
+    FileUtils.touch "README"
+    git_commit_all
+  end
+
+  describe "#source_modified_time" do
+    it "returns the right modification time" do
+      cached_location.cd do
+        setup_git_repo
+      end
+      expect(subject.source_modified_time.to_i).to eq(1_485_115_153)
+    end
+  end
+
+  specify "#last_commit" do
+    cached_location.cd do
+      setup_git_repo
+      FileUtils.touch "LICENSE"
+      git_commit_all
+    end
+    expect(subject.last_commit).to eq("f68266e")
+  end
+
+  describe "#fetch_last_commit" do
+    let(:url) { "file://#{remote_repo}" }
+    let(:version) { Version.create("HEAD") }
+    let(:resource) { double(Resource, url: url, mirrors: [], specs: {}, version: version) }
+    let(:remote_repo) { HOMEBREW_PREFIX/"remote_repo" }
+
+    before(:each) { remote_repo.mkpath }
+
+    after(:each) { FileUtils.rm_rf remote_repo }
+
+    it "fetches the hash of the last commit" do
+      remote_repo.cd do
+        setup_git_repo
+        FileUtils.touch "LICENSE"
+        git_commit_all
+      end
+
+      subject.shutup!
+      expect(subject.fetch_last_commit).to eq("f68266e")
+    end
+  end
+end
+
+describe DownloadStrategyDetector do
+  describe "::detect" do
+    subject { described_class.detect(url) }
+    let(:url) { Object.new }
+
+    context "when given Git URL" do
+      let(:url) { "git://example.com/foo.git" }
+      it { is_expected.to eq(GitDownloadStrategy) }
+    end
+
+    context "when given a GitHub Git URL" do
+      let(:url) { "https://github.com/homebrew/brew.git" }
+      it { is_expected.to eq(GitHubGitDownloadStrategy) }
+    end
+
+    it "defaults to cURL" do
+      expect(subject).to eq(CurlDownloadStrategy)
+    end
+
+    it "raises an error when passed an unrecognized strategy" do
+      expect {
+        described_class.detect("foo", Class.new)
+      }.to raise_error(TypeError)
+    end
+  end
+end
diff --git a/Library/Homebrew/test/download_strategies_test.rb b/Library/Homebrew/test/download_strategies_test.rb
deleted file mode 100644
index 40236b420a..0000000000
--- a/Library/Homebrew/test/download_strategies_test.rb
+++ /dev/null
@@ -1,245 +0,0 @@
-require "testing_env"
-require "download_strategy"
-
-class ResourceDouble
-  attr_reader :url, :specs, :version, :mirrors
-
-  def initialize(url = "http://example.com/foo.tar.gz", specs = {})
-    @url = url
-    @specs = specs
-    @mirrors = []
-  end
-end
-
-class AbstractDownloadStrategyTests < Homebrew::TestCase
-  include FileUtils
-
-  def setup
-    super
-    @name = "foo"
-    @resource = ResourceDouble.new
-    @strategy = AbstractDownloadStrategy.new(@name, @resource)
-    @args = %w[foo bar baz]
-  end
-
-  def test_expand_safe_system_args_with_explicit_quiet_flag
-    @args << { quiet_flag: "--flag" }
-    expanded_args = @strategy.expand_safe_system_args(@args)
-    assert_equal %w[foo bar baz --flag], expanded_args
-  end
-
-  def test_expand_safe_system_args_with_implicit_quiet_flag
-    expanded_args = @strategy.expand_safe_system_args(@args)
-    assert_equal %w[foo bar -q baz], expanded_args
-  end
-
-  def test_expand_safe_system_args_does_not_mutate_argument
-    result = @strategy.expand_safe_system_args(@args)
-    assert_equal %w[foo bar baz], @args
-    refute_same @args, result
-  end
-
-  def test_source_modified_time
-    mktemp "mtime" do
-      touch "foo", mtime: Time.now - 10
-      touch "bar", mtime: Time.now - 100
-      ln_s "not-exist", "baz"
-      assert_equal File.mtime("foo"), @strategy.source_modified_time
-    end
-  end
-end
-
-class VCSDownloadStrategyTests < Homebrew::TestCase
-  def test_cache_filename
-    resource = ResourceDouble.new("http://example.com/bar")
-    strategy = Class.new(VCSDownloadStrategy) do
-      def cache_tag
-        "foo"
-      end
-    end
-    downloader = strategy.new("baz", resource)
-    assert_equal HOMEBREW_CACHE.join("baz--foo"), downloader.cached_location
-  end
-end
-
-class GitHubPrivateRepositoryDownloadStrategyTests < Homebrew::TestCase
-  def setup
-    super
-    resource = ResourceDouble.new("https://github.com/owner/repo/archive/1.1.5.tar.gz")
-    ENV["HOMEBREW_GITHUB_API_TOKEN"] = "token"
-    GitHub.stubs(:repository).returns {}
-    @strategy = GitHubPrivateRepositoryDownloadStrategy.new("foo", resource)
-  end
-
-  def test_set_github_token
-    assert_equal "token", @strategy.instance_variable_get(:@github_token)
-  end
-
-  def test_parse_url_pattern
-    assert_equal "owner", @strategy.instance_variable_get(:@owner)
-    assert_equal "repo", @strategy.instance_variable_get(:@repo)
-    assert_equal "archive/1.1.5.tar.gz", @strategy.instance_variable_get(:@filepath)
-  end
-
-  def test_download_url
-    expected = "https://token@github.com/owner/repo/archive/1.1.5.tar.gz"
-    assert_equal expected, @strategy.download_url
-  end
-end
-
-class GitHubPrivateRepositoryReleaseDownloadStrategyTests < Homebrew::TestCase
-  def setup
-    super
-    resource = ResourceDouble.new("https://github.com/owner/repo/releases/download/tag/foo_v0.1.0_darwin_amd64.tar.gz")
-    ENV["HOMEBREW_GITHUB_API_TOKEN"] = "token"
-    GitHub.stubs(:repository).returns {}
-    @strategy = GitHubPrivateRepositoryReleaseDownloadStrategy.new("foo", resource)
-  end
-
-  def test_parse_url_pattern
-    assert_equal "owner", @strategy.instance_variable_get(:@owner)
-    assert_equal "repo", @strategy.instance_variable_get(:@repo)
-    assert_equal "tag", @strategy.instance_variable_get(:@tag)
-    assert_equal "foo_v0.1.0_darwin_amd64.tar.gz", @strategy.instance_variable_get(:@filename)
-  end
-
-  def test_download_url
-    @strategy.stubs(:resolve_asset_id).returns(456)
-    expected = "https://token@api.github.com/repos/owner/repo/releases/assets/456"
-    assert_equal expected, @strategy.download_url
-  end
-
-  def test_resolve_asset_id
-    release_metadata = {
-      "assets" => [
-        {
-          "id" => 123,
-          "name" => "foo_v0.1.0_linux_amd64.tar.gz",
-        },
-        {
-          "id" => 456,
-          "name" => "foo_v0.1.0_darwin_amd64.tar.gz",
-        },
-      ],
-    }
-    @strategy.stubs(:fetch_release_metadata).returns(release_metadata)
-    assert_equal 456, @strategy.send(:resolve_asset_id)
-  end
-
-  def test_fetch_release_metadata
-    expected_release_url = "https://api.github.com/repos/owner/repo/releases/tags/tag"
-    github_mock = MiniTest::Mock.new
-    github_mock.expect :call, {}, [expected_release_url]
-    GitHub.stub :open, github_mock do
-      @strategy.send(:fetch_release_metadata)
-    end
-    github_mock.verify
-  end
-end
-
-class GitDownloadStrategyTests < Homebrew::TestCase
-  include FileUtils
-
-  def setup
-    super
-    resource = ResourceDouble.new("https://github.com/homebrew/foo")
-    @commit_id = 1
-    @strategy = GitDownloadStrategy.new("baz", resource)
-    @cached_location = @strategy.cached_location
-    mkpath @cached_location
-  end
-
-  def git_commit_all
-    shutup do
-      system "git", "add", "--all"
-      system "git", "commit", "-m", "commit number #{@commit_id}"
-      @commit_id += 1
-    end
-  end
-
-  def setup_git_repo
-    @cached_location.cd do
-      shutup do
-        system "git", "init"
-        system "git", "remote", "add", "origin", "https://github.com/Homebrew/homebrew-foo"
-      end
-      touch "README"
-      git_commit_all
-    end
-  end
-
-  def test_github_git_download_strategy_user_repo
-    resource = ResourceDouble.new("https://github.com/homebrew/brew.git")
-    strategy = GitHubGitDownloadStrategy.new("brew", resource)
-
-    assert_equal strategy.instance_variable_get(:@user), "homebrew"
-    assert_equal strategy.instance_variable_get(:@repo), "brew"
-  end
-
-  def test_source_modified_time
-    setup_git_repo
-    assert_equal 1_485_115_153, @strategy.source_modified_time.to_i
-  end
-
-  def test_last_commit
-    setup_git_repo
-    @cached_location.cd do
-      touch "LICENSE"
-      git_commit_all
-    end
-    assert_equal "f68266e", @strategy.last_commit
-  end
-
-  def test_fetch_last_commit
-    remote_repo = HOMEBREW_PREFIX.join("remote_repo")
-    remote_repo.mkdir
-
-    resource = ResourceDouble.new("file://#{remote_repo}")
-    resource.instance_variable_set(:@version, Version.create("HEAD"))
-    @strategy = GitDownloadStrategy.new("baz", resource)
-
-    remote_repo.cd do
-      shutup do
-        system "git", "init"
-        system "git", "remote", "add", "origin", "https://github.com/Homebrew/homebrew-foo"
-      end
-      touch "README"
-      git_commit_all
-      touch "LICENSE"
-      git_commit_all
-    end
-
-    @strategy.shutup!
-    assert_equal "f68266e", @strategy.fetch_last_commit
-  ensure
-    remote_repo.rmtree if remote_repo.directory?
-  end
-end
-
-class DownloadStrategyDetectorTests < Homebrew::TestCase
-  def setup
-    super
-    @d = DownloadStrategyDetector.new
-  end
-
-  def test_detect_git_download_startegy
-    @d = DownloadStrategyDetector.detect("git://example.com/foo.git")
-    assert_equal GitDownloadStrategy, @d
-  end
-
-  def test_detect_github_git_download_strategy
-    @d = DownloadStrategyDetector.detect("https://github.com/homebrew/brew.git")
-    assert_equal GitHubGitDownloadStrategy, @d
-  end
-
-  def test_default_to_curl_strategy
-    @d = DownloadStrategyDetector.detect(Object.new)
-    assert_equal CurlDownloadStrategy, @d
-  end
-
-  def test_raises_when_passed_unrecognized_strategy
-    assert_raises(TypeError) do
-      DownloadStrategyDetector.detect("foo", Class.new)
-    end
-  end
-end