diff --git a/Library/Homebrew/test/utils/bottles/bintray_spec.rb b/Library/Homebrew/test/utils/bottles/bintray_spec.rb
new file mode 100644
index 0000000000..a7dfc00eab
--- /dev/null
+++ b/Library/Homebrew/test/utils/bottles/bintray_spec.rb
@@ -0,0 +1,18 @@
+require "utils/bottles"
+
+describe Utils::Bottles::Bintray do
+  describe "::package" do
+    it "converts a Formula name to a package name" do
+      expect(described_class.package("openssl@1.1")).to eq("openssl:1.1")
+      expect(described_class.package("gtk+")).to eq("gtkx")
+      expect(described_class.package("llvm")).to eq("llvm")
+    end
+  end
+
+  describe "::repository" do
+    it "returns the repository for a given Tap" do
+      expect(described_class.repository(Tap.new("homebrew", "bintray-test")))
+        .to eq("bottles-bintray-test")
+    end
+  end
+end
diff --git a/Library/Homebrew/test/utils/popen_spec.rb b/Library/Homebrew/test/utils/popen_spec.rb
new file mode 100644
index 0000000000..e3704a876a
--- /dev/null
+++ b/Library/Homebrew/test/utils/popen_spec.rb
@@ -0,0 +1,28 @@
+require "utils/popen"
+
+describe Utils do
+  describe "::popen_read" do
+    it "reads the standard output of a given command" do
+      expect(subject.popen_read("sh", "-c", "echo success").chomp).to eq("success")
+      expect($?).to be_a_success
+    end
+
+    it "can be given a block to manually read from the pipe" do
+      expect(
+        subject.popen_read("sh", "-c", "echo success") do |pipe|
+          pipe.read.chomp
+        end,
+      ).to eq("success")
+      expect($?).to be_a_success
+    end
+  end
+
+  describe "::popen_write" do
+    it "with supports writing to a command's standard input" do
+      subject.popen_write("grep", "-q", "success") do |pipe|
+        pipe.write("success\n")
+      end
+      expect($?).to be_a_success
+    end
+  end
+end
diff --git a/Library/Homebrew/test/utils_spec.rb b/Library/Homebrew/test/utils_spec.rb
new file mode 100644
index 0000000000..de6b287d27
--- /dev/null
+++ b/Library/Homebrew/test/utils_spec.rb
@@ -0,0 +1,283 @@
+require "utils"
+
+RSpec::Matchers.alias_matcher :have_failed, :be_failed
+
+describe "globally-scoped helper methods" do
+  let(:dir) { @dir = Pathname.new(Dir.mktmpdir) }
+
+  after(:each) { dir.rmtree unless @dir.nil? }
+
+  def esc(code)
+    /(\e\[\d+m)*\e\[#{code}m/
+  end
+
+  describe "#ofail" do
+    it "sets Homebrew.failed to true" do
+      begin
+        shutup do
+          ofail "foo"
+        end
+
+        expect(Homebrew).to have_failed
+      ensure
+        Homebrew.failed = false
+      end
+    end
+  end
+
+  describe "#odie" do
+    it "exits with 1" do
+      expect(self).to receive(:exit).and_return(1)
+      expect {
+        odie "foo"
+      }.to output("Error: foo\n").to_stderr
+    end
+  end
+
+  describe "#pretty_installed" do
+    subject { pretty_installed("foo") }
+
+    context "when $stdout is a TTY" do
+      before(:each) { allow($stdout).to receive(:tty?).and_return(true) }
+
+      context "with HOMEBREW_NO_EMOJI unset" do
+        before(:each) { ENV.delete("HOMEBREW_NO_EMOJI") }
+
+        it "returns a string with a colored checkmark" do
+          expect(subject)
+            .to match(/#{esc 1}foo #{esc 32}✔#{esc 0}/)
+        end
+      end
+
+      context "with HOMEBREW_NO_EMOJI set" do
+        before(:each) { ENV["HOMEBREW_NO_EMOJI"] = "1" }
+
+        it "returns a string with colored info" do
+          expect(subject)
+            .to match(/#{esc 1}foo \(installed\)#{esc 0}/)
+        end
+      end
+    end
+
+    context "when $stdout is not a TTY" do
+      before(:each) { allow($stdout).to receive(:tty?).and_return(false) }
+
+      it "returns plain text" do
+        expect(subject).to eq("foo")
+      end
+    end
+  end
+
+  describe "#pretty_uninstalled" do
+    subject { pretty_uninstalled("foo") }
+
+    context "when $stdout is a TTY" do
+      before(:each) { allow($stdout).to receive(:tty?).and_return(true) }
+
+      context "with HOMEBREW_NO_EMOJI unset" do
+        before(:each) { ENV.delete("HOMEBREW_NO_EMOJI") }
+
+        it "returns a string with a colored checkmark" do
+          expect(subject)
+            .to match(/#{esc 1}foo #{esc 31}✘#{esc 0}/)
+        end
+      end
+
+      context "with HOMEBREW_NO_EMOJI set" do
+        before(:each) { ENV["HOMEBREW_NO_EMOJI"] = "1" }
+
+        it "returns a string with colored info" do
+          expect(subject)
+            .to match(/#{esc 1}foo \(uninstalled\)#{esc 0}/)
+        end
+      end
+    end
+
+    context "when $stdout is not a TTY" do
+      before(:each) { allow($stdout).to receive(:tty?).and_return(false) }
+
+      it "returns plain text" do
+        expect(subject).to eq("foo")
+      end
+    end
+  end
+
+  describe "#interactive_shell" do
+    let(:shell) { dir/"myshell" }
+
+    it "starts an interactive shell session" do
+      IO.write shell, <<-EOS.undent
+        #!/bin/sh
+        echo called > "#{dir}/called"
+      EOS
+
+      FileUtils.chmod 0755, shell
+
+      ENV["SHELL"] = shell
+
+      expect { interactive_shell }.not_to raise_error
+      expect(dir/"called").to exist
+    end
+  end
+
+  describe "#with_custom_locale" do
+    it "temporarily overrides the system locale" do
+      ENV["LC_ALL"] = "en_US.UTF-8"
+
+      with_custom_locale("C") do
+        expect(ENV["LC_ALL"]).to eq("C")
+      end
+
+      expect(ENV["LC_ALL"]).to eq("en_US.UTF-8")
+    end
+  end
+
+  describe "#run_as_not_developer" do
+    it "temporarily unsets HOMEBREW_DEVELOPER" do
+      ENV["HOMEBREW_DEVELOPER"] = "foo"
+
+      run_as_not_developer do
+        expect(ENV["HOMEBREW_DEVELOPER"]).to be nil
+      end
+
+      expect(ENV["HOMEBREW_DEVELOPER"]).to eq("foo")
+    end
+  end
+
+  describe "#which" do
+    let(:cmd) { dir/"foo" }
+
+    before(:each) { FileUtils.touch cmd }
+
+    it "returns the first executable that is found" do
+      cmd.chmod 0744
+      expect(which(File.basename(cmd), File.dirname(cmd))).to eq(cmd)
+    end
+
+    it "skips non-executables" do
+      expect(which(File.basename(cmd), File.dirname(cmd))).to be nil
+    end
+
+    it "skips malformed path and doesn't fail" do
+      # 'which' should not fail if a path is malformed
+      # see https://github.com/Homebrew/legacy-homebrew/issues/32789 for an example
+      cmd.chmod 0744
+
+      # ~~ will fail because ~foo resolves to foo's home and there is no '~' user
+      path = ["~~", File.dirname(cmd)].join(File::PATH_SEPARATOR)
+      expect(which(File.basename(cmd), path)).to eq(cmd)
+    end
+  end
+
+  describe "#which_all" do
+    let(:cmd1) { dir/"foo" }
+    let(:cmd2) { dir/"bar/foo" }
+    let(:cmd3) { dir/"bar/baz/foo" }
+
+    before(:each) do
+      (dir/"bar/baz").mkpath
+
+      FileUtils.touch cmd2
+
+      [cmd1, cmd3].each do |cmd|
+        FileUtils.touch cmd
+        cmd.chmod 0744
+      end
+    end
+
+    it "returns an array of all executables that are found" do
+      path = [
+        "#{dir}/bar/baz",
+        "#{dir}/baz:#{dir}",
+        "~baduserpath",
+      ].join(File::PATH_SEPARATOR)
+      expect(which_all("foo", path)).to eq([cmd3, cmd1])
+    end
+  end
+
+  specify "#which_editor" do
+    ENV["HOMEBREW_EDITOR"] = "vemate"
+    expect(which_editor).to eq("vemate")
+  end
+
+  specify "#gzip" do
+    Dir.mktmpdir do |path|
+      path = Pathname.new(path)
+      somefile = path/"somefile"
+      FileUtils.touch somefile
+      expect(gzip(somefile)[0].to_s).to eq("#{somefile}.gz")
+      expect(Pathname.new("#{somefile}.gz")).to exist
+    end
+  end
+
+  specify "#capture_stderr" do
+    err = capture_stderr do
+      $stderr.print "test"
+    end
+
+    expect(err).to eq("test")
+  end
+
+  describe "#pretty_duration" do
+    it "converts seconds to a human-readable string" do
+      expect(pretty_duration(1)).to eq("1 second")
+      expect(pretty_duration(2.5)).to eq("2 seconds")
+      expect(pretty_duration(42)).to eq("42 seconds")
+      expect(pretty_duration(240)).to eq("4 minutes")
+      expect(pretty_duration(252.45)).to eq("4 minutes 12 seconds")
+    end
+  end
+
+  specify "#plural" do
+    expect(plural(1)).to eq("")
+    expect(plural(0)).to eq("s")
+    expect(plural(42)).to eq("s")
+    expect(plural(42, "")).to eq("")
+  end
+
+  specify "#disk_usage_readable" do
+    expect(disk_usage_readable(1)).to eq("1B")
+    expect(disk_usage_readable(1000)).to eq("1000B")
+    expect(disk_usage_readable(1024)).to eq("1K")
+    expect(disk_usage_readable(1025)).to eq("1K")
+    expect(disk_usage_readable(4_404_020)).to eq("4.2M")
+    expect(disk_usage_readable(4_509_715_660)).to eq("4.2G")
+  end
+
+  describe "#number_readable" do
+    it "returns a string with thousands separators" do
+      expect(number_readable(1)).to eq("1")
+      expect(number_readable(1_000)).to eq("1,000")
+      expect(number_readable(1_000_000)).to eq("1,000,000")
+    end
+  end
+
+  specify "#truncate_text_to_approximate_size" do
+    glue = "\n[...snip...]\n" # hard-coded copy from truncate_text_to_approximate_size
+    n = 20
+    long_s = "x" * 40
+
+    s = truncate_text_to_approximate_size(long_s, n)
+    expect(s.length).to eq(n)
+    expect(s).to match(/^x+#{Regexp.escape(glue)}x+$/)
+
+    s = truncate_text_to_approximate_size(long_s, n, front_weight: 0.0)
+    expect(s).to eq(glue + ("x" * (n - glue.length)))
+
+    s = truncate_text_to_approximate_size(long_s, n, front_weight: 1.0)
+    expect(s).to eq(("x" * (n - glue.length)) + glue)
+  end
+
+  describe "#odeprecated" do
+    it "raises a MethodDeprecatedError" do
+      ENV.delete("HOMEBREW_DEVELOPER")
+      expect {
+        odeprecated(
+          "method", "replacement",
+          caller: ["#{HOMEBREW_LIBRARY}/Taps/homebrew/homebrew-core/"],
+          disable: true
+        )
+      }.to raise_error(MethodDeprecatedError, %r{method.*replacement.*homebrew/homebrew-core.*homebrew/core}m)
+    end
+  end
+end
diff --git a/Library/Homebrew/test/utils_test.rb b/Library/Homebrew/test/utils_test.rb
deleted file mode 100644
index 1f2fb7b55f..0000000000
--- a/Library/Homebrew/test/utils_test.rb
+++ /dev/null
@@ -1,252 +0,0 @@
-require "testing_env"
-require "utils"
-require "tempfile"
-require "utils/shell"
-
-class UtilTests < Homebrew::TestCase
-  def setup
-    super
-    @dir = Pathname.new(mktmpdir)
-  end
-
-  def esc(code)
-    /(\e\[\d+m)*\e\[#{code}m/
-  end
-
-  def test_ofail
-    shutup { ofail "foo" }
-    assert Homebrew.failed?
-  ensure
-    Homebrew.failed = false
-  end
-
-  def test_odie
-    expects(:exit).returns 1
-    shutup { odie "foo" }
-  end
-
-  def test_pretty_installed
-    $stdout.stubs(:tty?).returns true
-    ENV.delete("HOMEBREW_NO_EMOJI")
-    tty_with_emoji_output = /\A#{esc 1}foo #{esc 32}✔#{esc 0}\Z/
-    assert_match tty_with_emoji_output, pretty_installed("foo")
-
-    ENV["HOMEBREW_NO_EMOJI"] = "1"
-    tty_no_emoji_output = /\A#{esc 1}foo \(installed\)#{esc 0}\Z/
-    assert_match tty_no_emoji_output, pretty_installed("foo")
-
-    $stdout.stubs(:tty?).returns false
-    assert_equal "foo", pretty_installed("foo")
-  end
-
-  def test_pretty_uninstalled
-    $stdout.stubs(:tty?).returns true
-    ENV.delete("HOMEBREW_NO_EMOJI")
-    tty_with_emoji_output = /\A#{esc 1}foo #{esc 31}✘#{esc 0}\Z/
-    assert_match tty_with_emoji_output, pretty_uninstalled("foo")
-
-    ENV["HOMEBREW_NO_EMOJI"] = "1"
-    tty_no_emoji_output = /\A#{esc 1}foo \(uninstalled\)#{esc 0}\Z/
-    assert_match tty_no_emoji_output, pretty_uninstalled("foo")
-
-    $stdout.stubs(:tty?).returns false
-    assert_equal "foo", pretty_uninstalled("foo")
-  end
-
-  def test_interactive_shell
-    mktmpdir do |path|
-      shell = "#{path}/myshell"
-      File.open(shell, "w") do |file|
-        file.write "#!/bin/sh\necho called > #{path}/called\n"
-      end
-      FileUtils.chmod 0755, shell
-      ENV["SHELL"] = shell
-      assert_nothing_raised { interactive_shell }
-      assert File.exist? "#{path}/called"
-    end
-  end
-
-  def test_with_custom_locale
-    ENV["LC_ALL"] = "en_US.UTF-8"
-    with_custom_locale("C") do
-      assert_equal "C", ENV["LC_ALL"]
-    end
-    assert_equal "en_US.UTF-8", ENV["LC_ALL"]
-  end
-
-  def test_run_as_not_developer
-    ENV["HOMEBREW_DEVELOPER"] = "foo"
-    run_as_not_developer do
-      assert_nil ENV["HOMEBREW_DEVELOPER"]
-    end
-    assert_equal "foo", ENV["HOMEBREW_DEVELOPER"]
-  end
-
-  def test_put_columns_empty
-    out, err = capture_io do
-      puts Formatter.columns([])
-    end
-
-    assert_equal out, "\n"
-    assert_equal err, ""
-  end
-
-  def test_which
-    cmd = @dir/"foo"
-    FileUtils.touch cmd
-    cmd.chmod 0744
-    assert_equal Pathname.new(cmd),
-      which(File.basename(cmd), File.dirname(cmd))
-  end
-
-  def test_which_skip_non_executables
-    cmd = @dir/"foo"
-    FileUtils.touch cmd
-    assert_nil which(File.basename(cmd), File.dirname(cmd))
-  end
-
-  def test_which_skip_malformed_path
-    # 'which' should not fail if a path is malformed
-    # see https://github.com/Homebrew/legacy-homebrew/issues/32789 for an example
-    cmd = @dir/"foo"
-    FileUtils.touch cmd
-    cmd.chmod 0744
-
-    # ~~ will fail because ~foo resolves to foo's home and there is no '~' user
-    # here
-    assert_equal Pathname.new(cmd),
-      which(File.basename(cmd), "~~#{File::PATH_SEPARATOR}#{File.dirname(cmd)}")
-  end
-
-  def test_which_all
-    (@dir/"bar/baz").mkpath
-    cmd1 = @dir/"foo"
-    cmd2 = @dir/"bar/foo"
-    cmd3 = @dir/"bar/baz/foo"
-    FileUtils.touch cmd2
-    [cmd1, cmd3].each do |cmd|
-      FileUtils.touch cmd
-      cmd.chmod 0744
-    end
-    assert_equal [cmd3, cmd1],
-      which_all("foo", "#{@dir}/bar/baz:#{@dir}/baz:#{@dir}:~baduserpath")
-  end
-
-  def test_which_editor
-    ENV["HOMEBREW_EDITOR"] = "vemate"
-    assert_equal "vemate", which_editor
-  end
-
-  def test_gzip
-    mktmpdir do |path|
-      somefile = "#{path}/somefile"
-      FileUtils.touch somefile
-      assert_equal "#{somefile}.gz",
-        gzip(somefile)[0].to_s
-      assert File.exist?("#{somefile}.gz")
-    end
-  end
-
-  def test_capture_stderr
-    assert_equal "test\n", capture_stderr { $stderr.puts "test" }
-  end
-
-  def test_shell_profile
-    ENV["SHELL"] = "/bin/sh"
-    assert_equal "~/.bash_profile", Utils::Shell.shell_profile
-    ENV["SHELL"] = "/bin/bash"
-    assert_equal "~/.bash_profile", Utils::Shell.shell_profile
-    ENV["SHELL"] = "/bin/another_shell"
-    assert_equal "~/.bash_profile", Utils::Shell.shell_profile
-    ENV["SHELL"] = "/bin/zsh"
-    assert_equal "~/.zshrc", Utils::Shell.shell_profile
-    ENV["SHELL"] = "/bin/ksh"
-    assert_equal "~/.kshrc", Utils::Shell.shell_profile
-  end
-
-  def test_popen_read
-    out = Utils.popen_read("sh", "-c", "echo success").chomp
-    assert_equal "success", out
-    assert_predicate $?, :success?
-  end
-
-  def test_popen_read_with_block
-    out = Utils.popen_read("sh", "-c", "echo success") do |pipe|
-      pipe.read.chomp
-    end
-    assert_equal "success", out
-    assert_predicate $?, :success?
-  end
-
-  def test_popen_write_with_block
-    Utils.popen_write("grep", "-q", "success") do |pipe|
-      pipe.write("success\n")
-    end
-    assert_predicate $?, :success?
-  end
-
-  def test_pretty_duration
-    assert_equal "1 second", pretty_duration(1)
-    assert_equal "2 seconds", pretty_duration(2.5)
-    assert_equal "42 seconds", pretty_duration(42)
-    assert_equal "4 minutes", pretty_duration(240)
-    assert_equal "4 minutes 12 seconds", pretty_duration(252.45)
-  end
-
-  def test_plural
-    assert_equal "", plural(1)
-    assert_equal "s", plural(0)
-    assert_equal "s", plural(42)
-    assert_equal "", plural(42, "")
-  end
-
-  def test_disk_usage_readable
-    assert_equal "1B", disk_usage_readable(1)
-    assert_equal "1000B", disk_usage_readable(1000)
-    assert_equal "1K", disk_usage_readable(1024)
-    assert_equal "1K", disk_usage_readable(1025)
-    assert_equal "4.2M", disk_usage_readable(4_404_020)
-    assert_equal "4.2G", disk_usage_readable(4_509_715_660)
-  end
-
-  def test_number_readable
-    assert_equal "1", number_readable(1)
-    assert_equal "1,000", number_readable(1_000)
-    assert_equal "1,000,000", number_readable(1_000_000)
-  end
-
-  def test_truncate_text_to_approximate_size
-    glue = "\n[...snip...]\n" # hard-coded copy from truncate_text_to_approximate_size
-    n = 20
-    long_s = "x" * 40
-    s = truncate_text_to_approximate_size(long_s, n)
-    assert_equal n, s.length
-    assert_match(/^x+#{Regexp.escape(glue)}x+$/, s)
-    s = truncate_text_to_approximate_size(long_s, n, front_weight: 0.0)
-    assert_equal glue + ("x" * (n - glue.length)), s
-    s = truncate_text_to_approximate_size(long_s, n, front_weight: 1.0)
-    assert_equal(("x" * (n - glue.length)) + glue, s)
-  end
-
-  def test_odeprecated
-    ENV.delete("HOMEBREW_DEVELOPER")
-    e = assert_raises(MethodDeprecatedError) do
-      odeprecated("method", "replacement",
-        caller: ["#{HOMEBREW_LIBRARY}/Taps/homebrew/homebrew-core/"],
-        disable: true)
-    end
-    assert_match "method", e.message
-    assert_match "replacement", e.message
-    assert_match "homebrew/homebrew-core", e.message
-    assert_match "homebrew/core", e.message
-  end
-
-  def test_bottles_bintray
-    assert_equal "openssl:1.1", Utils::Bottles::Bintray.package("openssl@1.1")
-    assert_equal "gtkx", Utils::Bottles::Bintray.package("gtk+")
-    assert_equal "llvm", Utils::Bottles::Bintray.package("llvm")
-
-    tap = Tap.new("homebrew", "bintray-test")
-    assert_equal "bottles-bintray-test", Utils::Bottles::Bintray.repository(tap)
-  end
-end