diff --git a/Library/Homebrew/test/diagnostic_spec.rb b/Library/Homebrew/test/diagnostic_spec.rb
new file mode 100644
index 0000000000..e749a3b0f4
--- /dev/null
+++ b/Library/Homebrew/test/diagnostic_spec.rb
@@ -0,0 +1,188 @@
+require "diagnostic"
+
+describe Homebrew::Diagnostic::Checks do
+  specify "#inject_file_list" do
+    expect(subject.inject_file_list([], "foo:\n")).to eq("foo:\n")
+    expect(subject.inject_file_list(%w[/a /b], "foo:\n")).to eq("foo:\n  /a\n  /b\n")
+  end
+
+  specify "#check_path_for_trailing_slashes" do
+    ENV["PATH"] += File::PATH_SEPARATOR + "/foo/bar/"
+    expect(subject.check_path_for_trailing_slashes)
+      .to match("Some directories in your path end in a slash")
+  end
+
+  specify "#check_for_anaconda" do
+    Dir.mktmpdir do |path|
+      anaconda = "#{path}/anaconda"
+      python = "#{path}/python"
+      FileUtils.touch anaconda
+      File.open(python, "w") do |file|
+        file.write("#! #{`which bash`}\necho -n '#{python}'\n")
+      end
+      FileUtils.chmod 0755, anaconda
+      FileUtils.chmod 0755, python
+
+      ENV["PATH"] = path + File::PATH_SEPARATOR + ENV["PATH"]
+
+      expect(subject.check_for_anaconda).to match("Anaconda")
+    end
+  end
+
+  specify "#check_access_homebrew_repository" do
+    begin
+      mode = HOMEBREW_REPOSITORY.stat.mode & 0777
+      HOMEBREW_REPOSITORY.chmod 0555
+
+      expect(subject.check_access_homebrew_repository)
+        .to match("#{HOMEBREW_REPOSITORY} is not writable.")
+    ensure
+      HOMEBREW_REPOSITORY.chmod mode
+    end
+  end
+
+  specify "#check_access_logs" do
+    begin
+      mode = HOMEBREW_LOGS.stat.mode & 0777
+      HOMEBREW_LOGS.chmod 0555
+
+      expect(subject.check_access_logs)
+        .to match("#{HOMEBREW_LOGS} isn't writable.")
+    ensure
+      HOMEBREW_LOGS.chmod mode
+    end
+  end
+
+  specify "#check_access_cache" do
+    begin
+      mode = HOMEBREW_CACHE.stat.mode & 0777
+      HOMEBREW_CACHE.chmod 0555
+      expect(subject.check_access_cache)
+        .to match("#{HOMEBREW_CACHE} isn't writable.")
+    ensure
+      HOMEBREW_CACHE.chmod mode
+    end
+  end
+
+  specify "#check_access_cellar" do
+    begin
+      mode = HOMEBREW_CELLAR.stat.mode & 0777
+      HOMEBREW_CELLAR.chmod 0555
+
+      expect(subject.check_access_cellar)
+        .to match("#{HOMEBREW_CELLAR} isn't writable.")
+    ensure
+      HOMEBREW_CELLAR.chmod mode
+    end
+  end
+
+  specify "#check_homebrew_prefix" do
+    ENV.delete("JENKINS_HOME")
+    # the integration tests are run in a special prefix
+    expect(subject.check_homebrew_prefix)
+      .to match("Your Homebrew's prefix is not /usr/local.")
+  end
+
+  specify "#check_user_path_1" do
+    bin = HOMEBREW_PREFIX/"bin"
+    sep = File::PATH_SEPARATOR
+    # ensure /usr/bin is before HOMEBREW_PREFIX/bin in the PATH
+    ENV["PATH"] = "/usr/bin#{sep}#{bin}#{sep}" +
+                  ENV["PATH"].gsub(%r{(?:^|#{sep})(?:/usr/bin|#{bin})}, "")
+
+    # ensure there's at least one file with the same name in both /usr/bin/ and
+    # HOMEBREW_PREFIX/bin/
+    (bin/File.basename(Dir["/usr/bin/*"].first)).mkpath
+
+    expect(subject.check_user_path_1)
+      .to match("/usr/bin occurs before #{HOMEBREW_PREFIX}/bin")
+  end
+
+  specify "#check_user_path_2" do
+    ENV["PATH"] = ENV["PATH"].gsub \
+      %r{(?:^|#{File::PATH_SEPARATOR})#{HOMEBREW_PREFIX}/bin}, ""
+
+    expect(subject.check_user_path_1).to be nil
+    expect(subject.check_user_path_2)
+      .to match("Homebrew's bin was not found in your PATH.")
+  end
+
+  specify "#check_user_path_3" do
+    begin
+      sbin = HOMEBREW_PREFIX/"sbin"
+      ENV["PATH"] = "#{HOMEBREW_PREFIX}/bin#{File::PATH_SEPARATOR}" +
+                    ENV["PATH"].gsub(/(?:^|#{Regexp.escape(File::PATH_SEPARATOR)})#{Regexp.escape(sbin)}/, "")
+      (sbin/"something").mkpath
+
+      expect(subject.check_user_path_1).to be nil
+      expect(subject.check_user_path_2).to be nil
+      expect(subject.check_user_path_3)
+        .to match("Homebrew's sbin was not found in your PATH")
+    ensure
+      sbin.rmtree
+    end
+  end
+
+  specify "#check_user_curlrc" do
+    Dir.mktmpdir do |path|
+      FileUtils.touch "#{path}/.curlrc"
+      ENV["CURL_HOME"] = path
+
+      expect(subject.check_user_curlrc).to match("You have a curlrc file")
+    end
+  end
+
+  specify "#check_for_config_scripts" do
+    Dir.mktmpdir do |path|
+      file = "#{path}/foo-config"
+      FileUtils.touch file
+      FileUtils.chmod 0755, file
+      ENV["PATH"] = "#{path}#{File::PATH_SEPARATOR}#{ENV["PATH"]}"
+
+      expect(subject.check_for_config_scripts)
+        .to match('"config" scripts exist')
+    end
+  end
+
+  specify "#check_dyld_vars" do
+    ENV["DYLD_INSERT_LIBRARIES"] = "foo"
+    expect(subject.check_dyld_vars).to match("Setting DYLD_INSERT_LIBRARIES")
+  end
+
+  specify "#check_for_symlinked_cellar" do
+    begin
+      HOMEBREW_CELLAR.rmtree
+
+      Dir.mktmpdir do |path|
+        FileUtils.ln_s path, HOMEBREW_CELLAR
+
+        expect(subject.check_for_symlinked_cellar).to match(path)
+      end
+    ensure
+      HOMEBREW_CELLAR.unlink
+      HOMEBREW_CELLAR.mkpath
+    end
+  end
+
+  specify "#check_tmpdir" do
+    ENV["TMPDIR"] = "/i/don/t/exis/t"
+    expect(subject.check_tmpdir).to match("doesn't exist")
+  end
+
+  specify "#check_for_external_cmd_name_conflict" do
+    Dir.mktmpdir do |path1|
+      Dir.mktmpdir do |path2|
+        [path1, path2].each do |path|
+          cmd = "#{path}/brew-foo"
+          FileUtils.touch cmd
+          FileUtils.chmod 0755, cmd
+        end
+
+        ENV["PATH"] = [path1, path2, ENV["PATH"]].join File::PATH_SEPARATOR
+
+        expect(subject.check_for_external_cmd_name_conflict)
+          .to match("brew-foo")
+      end
+    end
+  end
+end
diff --git a/Library/Homebrew/test/diagnostic_test.rb b/Library/Homebrew/test/diagnostic_test.rb
deleted file mode 100644
index 7a1fb25f79..0000000000
--- a/Library/Homebrew/test/diagnostic_test.rb
+++ /dev/null
@@ -1,192 +0,0 @@
-require "testing_env"
-require "fileutils"
-require "pathname"
-require "diagnostic"
-
-class DiagnosticChecksTest < Homebrew::TestCase
-  def setup
-    super
-    @checks = Homebrew::Diagnostic::Checks.new
-  end
-
-  def test_inject_file_list
-    assert_equal "foo:\n",
-      @checks.inject_file_list([], "foo:\n")
-    assert_equal "foo:\n  /a\n  /b\n",
-      @checks.inject_file_list(%w[/a /b], "foo:\n")
-  end
-
-  def test_check_path_for_trailing_slashes
-    ENV["PATH"] += File::PATH_SEPARATOR + "/foo/bar/"
-    assert_match "Some directories in your path end in a slash",
-      @checks.check_path_for_trailing_slashes
-  end
-
-  def test_check_for_anaconda
-    mktmpdir do |path|
-      anaconda = "#{path}/anaconda"
-      python = "#{path}/python"
-      FileUtils.touch anaconda
-      File.open(python, "w") do |file|
-        file.write("#! #{`which bash`}\necho -n '#{python}'\n")
-      end
-      FileUtils.chmod 0755, anaconda
-      FileUtils.chmod 0755, python
-
-      ENV["PATH"] = path + File::PATH_SEPARATOR + ENV["PATH"]
-
-      assert_match "Anaconda",
-        @checks.check_for_anaconda
-    end
-  end
-
-  def test_check_access_homebrew_repository
-    mod = HOMEBREW_REPOSITORY.stat.mode & 0777
-    HOMEBREW_REPOSITORY.chmod 0555
-
-    assert_match "#{HOMEBREW_REPOSITORY} is not writable.",
-      @checks.check_access_homebrew_repository
-  ensure
-    HOMEBREW_REPOSITORY.chmod mod
-  end
-
-  def test_check_access_logs
-    mod = HOMEBREW_LOGS.stat.mode & 0777
-    HOMEBREW_LOGS.chmod 0555
-
-    assert_match "#{HOMEBREW_LOGS} isn't writable.",
-      @checks.check_access_logs
-  ensure
-    HOMEBREW_LOGS.chmod mod
-  end
-
-  def test_check_access_cache
-    mod = HOMEBREW_CACHE.stat.mode & 0777
-    HOMEBREW_CACHE.chmod 0555
-    assert_match "#{HOMEBREW_CACHE} isn't writable.",
-      @checks.check_access_cache
-  ensure
-    HOMEBREW_CACHE.chmod mod
-  end
-
-  def test_check_access_cellar
-    mod = HOMEBREW_CELLAR.stat.mode & 0777
-    HOMEBREW_CELLAR.chmod 0555
-
-    assert_match "#{HOMEBREW_CELLAR} isn't writable.",
-      @checks.check_access_cellar
-  ensure
-    HOMEBREW_CELLAR.chmod mod
-  end
-
-  def test_check_homebrew_prefix
-    ENV.delete("JENKINS_HOME")
-    # the integration tests are run in a special prefix
-    assert_match "Your Homebrew's prefix is not /usr/local.",
-      @checks.check_homebrew_prefix
-  end
-
-  def test_check_user_path_usr_bin_before_homebrew
-    bin = HOMEBREW_PREFIX/"bin"
-    sep = File::PATH_SEPARATOR
-    # ensure /usr/bin is before HOMEBREW_PREFIX/bin in the PATH
-    ENV["PATH"] = "/usr/bin#{sep}#{bin}#{sep}" +
-                  ENV["PATH"].gsub(%r{(?:^|#{sep})(?:/usr/bin|#{bin})}, "")
-
-    # ensure there's at least one file with the same name in both /usr/bin/ and
-    # HOMEBREW_PREFIX/bin/
-    (bin/File.basename(Dir["/usr/bin/*"].first)).mkpath
-
-    assert_match "/usr/bin occurs before #{HOMEBREW_PREFIX}/bin",
-      @checks.check_user_path_1
-  end
-
-  def test_check_user_path_bin
-    ENV["PATH"] = ENV["PATH"].gsub \
-      %r{(?:^|#{File::PATH_SEPARATOR})#{HOMEBREW_PREFIX}/bin}, ""
-
-    assert_nil @checks.check_user_path_1
-    assert_match "Homebrew's bin was not found in your PATH.",
-      @checks.check_user_path_2
-  end
-
-  def test_check_user_path_sbin
-    sbin = HOMEBREW_PREFIX/"sbin"
-    ENV["PATH"] = "#{HOMEBREW_PREFIX}/bin#{File::PATH_SEPARATOR}" +
-                  ENV["PATH"].gsub(/(?:^|#{Regexp.escape(File::PATH_SEPARATOR)})#{Regexp.escape(sbin)}/, "")
-    (sbin/"something").mkpath
-
-    assert_nil @checks.check_user_path_1
-    assert_nil @checks.check_user_path_2
-    assert_match "Homebrew's sbin was not found in your PATH",
-      @checks.check_user_path_3
-  ensure
-    sbin.rmtree
-  end
-
-  def test_check_user_curlrc
-    mktmpdir do |path|
-      FileUtils.touch "#{path}/.curlrc"
-      ENV["CURL_HOME"] = path
-
-      assert_match "You have a curlrc file",
-        @checks.check_user_curlrc
-    end
-  end
-
-  def test_check_for_config_scripts
-    mktmpdir do |path|
-      file = "#{path}/foo-config"
-      FileUtils.touch file
-      FileUtils.chmod 0755, file
-      ENV["PATH"] = "#{path}#{File::PATH_SEPARATOR}#{ENV["PATH"]}"
-
-      assert_match '"config" scripts exist',
-        @checks.check_for_config_scripts
-    end
-  end
-
-  def test_check_dyld_vars
-    ENV["DYLD_INSERT_LIBRARIES"] = "foo"
-    assert_match "Setting DYLD_INSERT_LIBRARIES",
-      @checks.check_dyld_vars
-  end
-
-  def test_check_for_symlinked_cellar
-    HOMEBREW_CELLAR.rmtree
-
-    mktmpdir do |path|
-      FileUtils.ln_s path, HOMEBREW_CELLAR
-
-      assert_match path,
-        @checks.check_for_symlinked_cellar
-    end
-
-  ensure
-    HOMEBREW_CELLAR.unlink
-    HOMEBREW_CELLAR.mkpath
-  end
-
-  def test_check_tmpdir
-    ENV["TMPDIR"] = "/i/don/t/exis/t"
-    assert_match "doesn't exist",
-      @checks.check_tmpdir
-  end
-
-  def test_check_for_external_cmd_name_conflict
-    mktmpdir do |path1|
-      mktmpdir do |path2|
-        [path1, path2].each do |path|
-          cmd = "#{path}/brew-foo"
-          FileUtils.touch cmd
-          FileUtils.chmod 0755, cmd
-        end
-
-        ENV["PATH"] = [path1, path2, ENV["PATH"]].join File::PATH_SEPARATOR
-
-        assert_match "brew-foo",
-          @checks.check_for_external_cmd_name_conflict
-      end
-    end
-  end
-end