diff --git a/Library/Homebrew/test/cmd/update-report_spec.rb b/Library/Homebrew/test/cmd/update-report_spec.rb
new file mode 100644
index 0000000000..3665e3c78b
--- /dev/null
+++ b/Library/Homebrew/test/cmd/update-report_spec.rb
@@ -0,0 +1,127 @@
+require "cmd/update-report"
+require "formula_versions"
+require "yaml"
+
+describe Reporter do
+  def perform_update(fixture_name = "")
+    allow(Formulary).to receive(:factory).and_return(double(pkg_version: "1.0"))
+    allow(FormulaVersions).to receive(:new).and_return(double(formula_at_revision: "2.0"))
+
+    diff = YAML.load_file("#{TEST_FIXTURE_DIR}/updater_fixture.yaml")[fixture_name]
+    allow(subject).to receive(:diff).and_return(diff || "")
+
+    hub.add(subject) if subject.updated?
+  end
+
+  let(:reporter_class) do
+    Class.new(described_class) do
+      def initialize(tap)
+        @tap = tap
+
+        ENV["HOMEBREW_UPDATE_BEFORE#{repo_var}"] = "12345678"
+        ENV["HOMEBREW_UPDATE_AFTER#{repo_var}"] = "abcdef00"
+
+        super(tap)
+      end
+    end
+  end
+  subject { reporter_class.new(tap) }
+  let(:tap) { CoreTap.new }
+  let(:hub) { ReporterHub.new }
+
+  specify "without revision variable" do
+    ENV.delete_if { |k, _v| k.start_with? "HOMEBREW_UPDATE" }
+
+    expect {
+      described_class.new(tap)
+    }.to raise_error(Reporter::ReporterRevisionUnsetError)
+  end
+
+  specify "without any changes" do
+    perform_update
+    expect(hub).to be_empty
+  end
+
+  specify "without Formula changes" do
+    perform_update("update_git_diff_output_without_formulae_changes")
+
+    expect(hub.select_formula(:M)).to be_empty
+    expect(hub.select_formula(:A)).to be_empty
+    expect(hub.select_formula(:D)).to be_empty
+  end
+
+  specify "with Formula changes" do
+    perform_update("update_git_diff_output_with_formulae_changes")
+
+    expect(hub.select_formula(:M)).to eq(%w[xar yajl])
+    expect(hub.select_formula(:A)).to eq(%w[antiword bash-completion ddrescue dict lua])
+  end
+
+  specify "with removed Formulae" do
+    perform_update("update_git_diff_output_with_removed_formulae")
+
+    expect(hub.select_formula(:D)).to eq(%w[libgsasl])
+  end
+
+  specify "with changed file type" do
+    perform_update("update_git_diff_output_with_changed_filetype")
+
+    expect(hub.select_formula(:M)).to eq(%w[elixir])
+    expect(hub.select_formula(:A)).to eq(%w[libbson])
+    expect(hub.select_formula(:D)).to eq(%w[libgsasl])
+  end
+
+  specify "with renamed Formula" do
+    allow(tap).to receive(:formula_renames).and_return("cv" => "progress")
+    perform_update("update_git_diff_output_with_formula_rename")
+
+    expect(hub.select_formula(:A)).to be_empty
+    expect(hub.select_formula(:D)).to be_empty
+    expect(hub.select_formula(:R)).to eq([["cv", "progress"]])
+  end
+
+  context "when updating a Tap other than the core Tap" do
+    let(:tap) { Tap.new("foo", "bar") }
+
+    before(:each) do
+      (tap.path/"Formula").mkpath
+    end
+
+    after(:each) do
+      tap.path.parent.rmtree
+    end
+
+    specify "with restructured Tap" do
+      perform_update("update_git_diff_output_with_restructured_tap")
+
+      expect(hub.select_formula(:A)).to be_empty
+      expect(hub.select_formula(:D)).to be_empty
+      expect(hub.select_formula(:R)).to be_empty
+    end
+
+    specify "with renamed Formula and restructured Tap" do
+      allow(tap).to receive(:formula_renames).and_return("xchat" => "xchat2")
+      perform_update("update_git_diff_output_with_formula_rename_and_restructuring")
+
+      expect(hub.select_formula(:A)).to be_empty
+      expect(hub.select_formula(:D)).to be_empty
+      expect(hub.select_formula(:R)).to eq([%w[foo/bar/xchat foo/bar/xchat2]])
+    end
+
+    specify "with simulated 'homebrew/php' restructuring" do
+      perform_update("update_git_diff_simulate_homebrew_php_restructuring")
+
+      expect(hub.select_formula(:A)).to be_empty
+      expect(hub.select_formula(:D)).to be_empty
+      expect(hub.select_formula(:R)).to be_empty
+    end
+
+    specify "with Formula changes" do
+      perform_update("update_git_diff_output_with_tap_formulae_changes")
+
+      expect(hub.select_formula(:A)).to eq(%w[foo/bar/lua])
+      expect(hub.select_formula(:M)).to eq(%w[foo/bar/git])
+      expect(hub.select_formula(:D)).to be_empty
+    end
+  end
+end
diff --git a/Library/Homebrew/test/update_report_test.rb b/Library/Homebrew/test/update_report_test.rb
deleted file mode 100644
index 32c3e36d0a..0000000000
--- a/Library/Homebrew/test/update_report_test.rb
+++ /dev/null
@@ -1,135 +0,0 @@
-require "testing_env"
-require "cmd/update-report"
-require "formula_versions"
-require "yaml"
-
-class ReportTests < Homebrew::TestCase
-  class ReporterMock < ::Reporter
-    attr_accessor :diff
-
-    def initialize(tap)
-      @tap = tap
-      ENV["HOMEBREW_UPDATE_BEFORE#{repo_var}"] = "12345678"
-      ENV["HOMEBREW_UPDATE_AFTER#{repo_var}"] = "abcdef12"
-      super(tap)
-    end
-  end
-
-  def fixture(name)
-    self.class.fixture_data[name] || ""
-  end
-
-  def self.fixture_data
-    @fixture_data ||= YAML.load_file("#{TEST_FIXTURE_DIR}/updater_fixture.yaml")
-  end
-
-  def setup
-    super
-    @tap = CoreTap.new
-    @reporter = ReporterMock.new(@tap)
-    @hub = ReporterHub.new
-  end
-
-  def perform_update(fixture_name = "")
-    Formulary.stubs(:factory).returns(stub(pkg_version: "1.0"))
-    FormulaVersions.stubs(:new).returns(stub(formula_at_revision: "2.0"))
-    @reporter.diff = fixture(fixture_name)
-    @hub.add(@reporter) if @reporter.updated?
-  end
-
-  def test_update_report_without_revision_var
-    ENV.delete_if { |k, _v| k.start_with? "HOMEBREW_UPDATE" }
-    assert_raises(Reporter::ReporterRevisionUnsetError) { Reporter.new(@tap) }
-  end
-
-  def test_update_homebrew_without_any_changes
-    perform_update
-    assert_empty @hub
-  end
-
-  def test_update_homebrew_without_formulae_changes
-    perform_update("update_git_diff_output_without_formulae_changes")
-    assert_empty @hub.select_formula(:M)
-    assert_empty @hub.select_formula(:A)
-    assert_empty @hub.select_formula(:D)
-  end
-
-  def test_update_homebrew_with_formulae_changes
-    perform_update("update_git_diff_output_with_formulae_changes")
-    assert_equal %w[xar yajl], @hub.select_formula(:M)
-    assert_equal %w[antiword bash-completion ddrescue dict lua], @hub.select_formula(:A)
-  end
-
-  def test_update_homebrew_with_removed_formulae
-    perform_update("update_git_diff_output_with_removed_formulae")
-    assert_equal %w[libgsasl], @hub.select_formula(:D)
-  end
-
-  def test_update_homebrew_with_changed_filetype
-    perform_update("update_git_diff_output_with_changed_filetype")
-    assert_equal %w[elixir], @hub.select_formula(:M)
-    assert_equal %w[libbson], @hub.select_formula(:A)
-    assert_equal %w[libgsasl], @hub.select_formula(:D)
-  end
-
-  def test_update_homebrew_with_formula_rename
-    @tap.stubs(:formula_renames).returns("cv" => "progress")
-    perform_update("update_git_diff_output_with_formula_rename")
-    assert_empty @hub.select_formula(:A)
-    assert_empty @hub.select_formula(:D)
-    assert_equal [["cv", "progress"]], @hub.select_formula(:R)
-  end
-
-  def test_update_homebrew_with_restructured_tap
-    tap = Tap.new("foo", "bar")
-    @reporter = ReporterMock.new(tap)
-    tap.path.join("Formula").mkpath
-
-    perform_update("update_git_diff_output_with_restructured_tap")
-    assert_empty @hub.select_formula(:A)
-    assert_empty @hub.select_formula(:D)
-    assert_empty @hub.select_formula(:R)
-  ensure
-    tap.path.parent.rmtree
-  end
-
-  def test_update_homebrew_with_formula_rename_and_restructuring
-    tap = Tap.new("foo", "bar")
-    @reporter = ReporterMock.new(tap)
-    tap.path.join("Formula").mkpath
-    tap.stubs(:formula_renames).returns("xchat" => "xchat2")
-
-    perform_update("update_git_diff_output_with_formula_rename_and_restructuring")
-    assert_empty @hub.select_formula(:A)
-    assert_empty @hub.select_formula(:D)
-    assert_equal [%w[foo/bar/xchat foo/bar/xchat2]], @hub.select_formula(:R)
-  ensure
-    tap.path.parent.rmtree
-  end
-
-  def test_update_homebrew_simulate_homebrew_php_restructuring
-    tap = Tap.new("foo", "bar")
-    @reporter = ReporterMock.new(tap)
-    tap.path.join("Formula").mkpath
-
-    perform_update("update_git_diff_simulate_homebrew_php_restructuring")
-    assert_empty @hub.select_formula(:A)
-    assert_empty @hub.select_formula(:D)
-    assert_empty @hub.select_formula(:R)
-  ensure
-    tap.path.parent.rmtree
-  end
-
-  def test_update_homebrew_with_tap_formulae_changes
-    tap = Tap.new("foo", "bar")
-    @reporter = ReporterMock.new(tap)
-    tap.path.join("Formula").mkpath
-
-    perform_update("update_git_diff_output_with_tap_formulae_changes")
-    assert_equal %w[foo/bar/lua], @hub.select_formula(:A)
-    assert_equal %w[foo/bar/git], @hub.select_formula(:M)
-    assert_empty @hub.select_formula(:D)
-  ensure
-    tap.path.parent.rmtree
-  end
-end