diff --git a/Library/Homebrew/test/build_environment_spec.rb b/Library/Homebrew/test/build_environment_spec.rb
index b073335a7e..51ae23af7e 100644
--- a/Library/Homebrew/test/build_environment_spec.rb
+++ b/Library/Homebrew/test/build_environment_spec.rb
@@ -30,11 +30,16 @@ describe BuildEnvironment do
   end
 
   describe BuildEnvironment::DSL do
-    subject(:build_environment_dsl) { double.extend(described_class) }
+    let(:build_environment_dsl) do
+      klass = described_class
+      Class.new do
+        extend(klass)
+      end
+    end
 
     context "with a single argument" do
-      before do
-        build_environment_dsl.instance_eval do
+      subject do
+        Class.new(build_environment_dsl) do
           env :std
         end
       end
diff --git a/Library/Homebrew/test/cleaner_spec.rb b/Library/Homebrew/test/cleaner_spec.rb
index a9c3d1f667..9e2c76e5f1 100644
--- a/Library/Homebrew/test/cleaner_spec.rb
+++ b/Library/Homebrew/test/cleaner_spec.rb
@@ -7,15 +7,15 @@ require "formula"
 describe Cleaner do
   include FileUtils
 
-  subject(:cleaner) { described_class.new(f) }
-
-  let(:f) { formula("cleaner_test") { url "foo-1.0" } }
-
-  before do
-    f.prefix.mkpath
-  end
-
   describe "#clean" do
+    subject(:cleaner) { described_class.new(f) }
+
+    let(:f) { formula("cleaner_test") { url "foo-1.0" } }
+
+    before do
+      f.prefix.mkpath
+    end
+
     it "cleans files" do
       f.bin.mkpath
       f.lib.mkpath
@@ -159,45 +159,54 @@ describe Cleaner do
   end
 
   describe "::skip_clean" do
+    def stub_formula_skip_clean(skip_paths)
+      formula("cleaner_test") do
+        url "foo-1.0"
+
+        skip_clean skip_paths
+      end
+    end
+
     it "adds paths that should be skipped" do
-      f.class.skip_clean "bin"
+      f = stub_formula_skip_clean("bin")
       f.bin.mkpath
 
-      cleaner.clean
+      described_class.new(f).clean
 
       expect(f.bin).to be_a_directory
     end
 
     it "also skips empty sub-directories under the added paths" do
-      f.class.skip_clean "bin"
+      f = stub_formula_skip_clean("bin")
       subdir = f.bin/"subdir"
       subdir.mkpath
 
-      cleaner.clean
+      described_class.new(f).clean
 
       expect(f.bin).to be_a_directory
       expect(subdir).to be_a_directory
     end
 
     it "allows skipping broken symlinks" do
-      f.class.skip_clean "symlink"
+      f = stub_formula_skip_clean("symlink")
+      f.prefix.mkpath
       symlink = f.prefix/"symlink"
       ln_s "target", symlink
 
-      cleaner.clean
+      described_class.new(f).clean
 
       expect(symlink).to be_a_symlink
     end
 
     it "allows skipping symlinks pointing to an empty directory" do
-      f.class.skip_clean "c"
+      f = stub_formula_skip_clean("c")
       dir = f.prefix/"b"
       symlink = f.prefix/"c"
 
       dir.mkpath
       ln_s dir.basename, symlink
 
-      cleaner.clean
+      described_class.new(f).clean
 
       expect(dir).not_to exist
       expect(symlink).to be_a_symlink
@@ -205,14 +214,14 @@ describe Cleaner do
     end
 
     it "allows skipping symlinks whose target was pruned before" do
-      f.class.skip_clean "a"
+      f = stub_formula_skip_clean("a")
       dir = f.prefix/"b"
       symlink = f.prefix/"a"
 
       dir.mkpath
       ln_s dir.basename, symlink
 
-      cleaner.clean
+      described_class.new(f).clean
 
       expect(dir).not_to exist
       expect(symlink).to be_a_symlink
@@ -220,37 +229,40 @@ describe Cleaner do
     end
 
     it "allows skipping '.la' files" do
+      f = stub_formula_skip_clean(:la)
+
       file = f.lib/"foo.la"
 
-      f.class.skip_clean :la
       f.lib.mkpath
       touch file
 
-      cleaner.clean
+      described_class.new(f).clean
 
       expect(file).to exist
     end
 
     it "allows skipping sub-directories" do
+      f = stub_formula_skip_clean("lib/subdir")
+
       dir = f.lib/"subdir"
-      f.class.skip_clean "lib/subdir"
 
       dir.mkpath
 
-      cleaner.clean
+      described_class.new(f).clean
 
       expect(dir).to be_a_directory
     end
 
     it "allows skipping paths relative to prefix" do
+      f = stub_formula_skip_clean("bin/a")
+
       dir1 = f.bin/"a"
       dir2 = f.lib/"bin/a"
 
-      f.class.skip_clean "bin/a"
       dir1.mkpath
       dir2.mkpath
 
-      cleaner.clean
+      described_class.new(f).clean
 
       expect(dir1).to exist
       expect(dir2).not_to exist
diff --git a/Library/Homebrew/test/formula_spec.rb b/Library/Homebrew/test/formula_spec.rb
index 71f997c3df..71ad626a6f 100644
--- a/Library/Homebrew/test/formula_spec.rb
+++ b/Library/Homebrew/test/formula_spec.rb
@@ -832,15 +832,15 @@ describe Formula do
     specify "service complicated" do
       f = formula do
         url "https://brew.sh/test-1.0.tbz"
-      end
 
-      f.class.service do
-        run [opt_bin/"beanstalkd"]
-        run_type :immediate
-        error_log_path var/"log/beanstalkd.error.log"
-        log_path var/"log/beanstalkd.log"
-        working_dir var
-        keep_alive true
+        service do
+          run [opt_bin/"beanstalkd"]
+          run_type :immediate
+          error_log_path var/"log/beanstalkd.error.log"
+          log_path var/"log/beanstalkd.log"
+          working_dir var
+          keep_alive true
+        end
       end
       expect(f.service).not_to be_nil
     end
diff --git a/Library/Homebrew/test/livecheck/livecheck_spec.rb b/Library/Homebrew/test/livecheck/livecheck_spec.rb
index 9b68e3f94b..02ba9f58eb 100644
--- a/Library/Homebrew/test/livecheck/livecheck_spec.rb
+++ b/Library/Homebrew/test/livecheck/livecheck_spec.rb
@@ -98,11 +98,15 @@ describe Homebrew::Livecheck do
 
   describe "::livecheck_url_to_string" do
     let(:f_livecheck_url) do
+      homepage_url_s = homepage_url
+      stable_url_s = stable_url
+      head_url_s = head_url
+
       formula("test_livecheck_url") do
         desc "Test Livecheck URL formula"
-        homepage "https://brew.sh"
-        url "https://brew.sh/test-0.0.1.tgz"
-        head "https://github.com/Homebrew/brew.git"
+        homepage homepage_url_s
+        url stable_url_s
+        head head_url_s
       end
     end
 
@@ -120,25 +124,15 @@ describe Homebrew::Livecheck do
     end
 
     it "returns a URL string when given a livecheck_url string" do
-      f_livecheck_url.livecheck.url(livecheck_url)
       expect(livecheck.livecheck_url_to_string(livecheck_url, f_livecheck_url)).to eq(livecheck_url)
     end
 
     it "returns a URL symbol when given a valid livecheck_url symbol" do
-      f_livecheck_url.livecheck.url(:head)
-      expect(livecheck.livecheck_url_to_string(head_url, f_livecheck_url)).to eq(head_url)
-
-      f_livecheck_url.livecheck.url(:homepage)
-      expect(livecheck.livecheck_url_to_string(homepage_url, f_livecheck_url)).to eq(homepage_url)
-
-      c_livecheck_url.livecheck.url(:homepage)
-      expect(livecheck.livecheck_url_to_string(homepage_url, c_livecheck_url)).to eq(homepage_url)
-
-      f_livecheck_url.livecheck.url(:stable)
-      expect(livecheck.livecheck_url_to_string(stable_url, f_livecheck_url)).to eq(stable_url)
-
-      c_livecheck_url.livecheck.url(:url)
-      expect(livecheck.livecheck_url_to_string(cask_url, c_livecheck_url)).to eq(cask_url)
+      expect(livecheck.livecheck_url_to_string(:head, f_livecheck_url)).to eq(head_url)
+      expect(livecheck.livecheck_url_to_string(:homepage, f_livecheck_url)).to eq(homepage_url)
+      expect(livecheck.livecheck_url_to_string(:homepage, c_livecheck_url)).to eq(homepage_url)
+      expect(livecheck.livecheck_url_to_string(:stable, f_livecheck_url)).to eq(stable_url)
+      expect(livecheck.livecheck_url_to_string(:url, c_livecheck_url)).to eq(cask_url)
     end
 
     it "returns nil when not given a string or valid symbol" do
diff --git a/Library/Homebrew/test/service_spec.rb b/Library/Homebrew/test/service_spec.rb
index e35f0f4cb9..e3fab49f3a 100644
--- a/Library/Homebrew/test/service_spec.rb
+++ b/Library/Homebrew/test/service_spec.rb
@@ -5,26 +5,28 @@ require "formula"
 require "service"
 
 describe Homebrew::Service do
-  let(:klass) do
-    Class.new(Formula) do
+  let(:name) { "formula_name" }
+
+  def stub_formula(&block)
+    formula(name) do
       url "https://brew.sh/test-1.0.tbz"
+
+      instance_eval(&block) if block
     end
   end
-  let(:name) { "formula_name" }
-  let(:path) { Formulary.core_path(name) }
-  let(:spec) { :stable }
-  let(:f) { klass.new(name, path, spec) }
 
   describe "#std_service_path_env" do
     it "returns valid std_service_path_env" do
-      f.class.service do
-        run opt_bin/"beanstalkd"
-        run_type :immediate
-        environment_variables PATH: std_service_path_env
-        error_log_path var/"log/beanstalkd.error.log"
-        log_path var/"log/beanstalkd.log"
-        working_dir var
-        keep_alive true
+      f = stub_formula do
+        service do
+          run opt_bin/"beanstalkd"
+          run_type :immediate
+          environment_variables PATH: std_service_path_env
+          error_log_path var/"log/beanstalkd.error.log"
+          log_path var/"log/beanstalkd.log"
+          working_dir var
+          keep_alive true
+        end
       end
 
       path = f.service.std_service_path_env
@@ -34,9 +36,11 @@ describe Homebrew::Service do
 
   describe "#process_type" do
     it "throws for unexpected type" do
-      f.class.service do
-        run opt_bin/"beanstalkd"
-        process_type :cow
+      f = stub_formula do
+        service do
+          run opt_bin/"beanstalkd"
+          process_type :cow
+        end
       end
 
       expect {
@@ -47,9 +51,11 @@ describe Homebrew::Service do
 
   describe "#keep_alive" do
     it "throws for unexpected keys" do
-      f.class.service do
-        run opt_bin/"beanstalkd"
-        keep_alive test: "key"
+      f = stub_formula do
+        service do
+          run opt_bin/"beanstalkd"
+          keep_alive test: "key"
+        end
       end
 
       expect {
@@ -60,9 +66,11 @@ describe Homebrew::Service do
 
   describe "#run_type" do
     it "throws for unexpected type" do
-      f.class.service do
-        run opt_bin/"beanstalkd"
-        run_type :cow
+      f = stub_formula do
+        service do
+          run opt_bin/"beanstalkd"
+          run_type :cow
+        end
       end
 
       expect {
@@ -73,9 +81,11 @@ describe Homebrew::Service do
 
   describe "#sockets" do
     it "throws for missing type" do
-      f.class.service do
-        run opt_bin/"beanstalkd"
-        sockets "127.0.0.1:80"
+      f = stub_formula do
+        service do
+          run opt_bin/"beanstalkd"
+          sockets "127.0.0.1:80"
+        end
       end
 
       expect {
@@ -84,9 +94,11 @@ describe Homebrew::Service do
     end
 
     it "throws for missing host" do
-      f.class.service do
-        run opt_bin/"beanstalkd"
-        sockets "tcp://:80"
+      f = stub_formula do
+        service do
+          run opt_bin/"beanstalkd"
+          sockets "tcp://:80"
+        end
       end
 
       expect {
@@ -95,9 +107,11 @@ describe Homebrew::Service do
     end
 
     it "throws for missing port" do
-      f.class.service do
-        run opt_bin/"beanstalkd"
-        sockets "tcp://127.0.0.1"
+      f = stub_formula do
+        service do
+          run opt_bin/"beanstalkd"
+          sockets "tcp://127.0.0.1"
+        end
       end
 
       expect {
@@ -108,14 +122,16 @@ describe Homebrew::Service do
 
   describe "#manual_command" do
     it "returns valid manual_command" do
-      f.class.service do
-        run "#{HOMEBREW_PREFIX}/bin/beanstalkd"
-        run_type :immediate
-        environment_variables PATH: std_service_path_env, ETC_DIR: etc/"beanstalkd"
-        error_log_path var/"log/beanstalkd.error.log"
-        log_path var/"log/beanstalkd.log"
-        working_dir var
-        keep_alive true
+      f = stub_formula do
+        service do
+          run "#{HOMEBREW_PREFIX}/bin/beanstalkd"
+          run_type :immediate
+          environment_variables PATH: std_service_path_env, ETC_DIR: etc/"beanstalkd"
+          error_log_path var/"log/beanstalkd.error.log"
+          log_path var/"log/beanstalkd.log"
+          working_dir var
+          keep_alive true
+        end
       end
 
       path = f.service.manual_command
@@ -123,14 +139,16 @@ describe Homebrew::Service do
     end
 
     it "returns valid manual_command without variables" do
-      f.class.service do
-        run opt_bin/"beanstalkd"
-        run_type :immediate
-        environment_variables PATH: std_service_path_env
-        error_log_path var/"log/beanstalkd.error.log"
-        log_path var/"log/beanstalkd.log"
-        working_dir var
-        keep_alive true
+      f = stub_formula do
+        service do
+          run opt_bin/"beanstalkd"
+          run_type :immediate
+          environment_variables PATH: std_service_path_env
+          error_log_path var/"log/beanstalkd.error.log"
+          log_path var/"log/beanstalkd.log"
+          working_dir var
+          keep_alive true
+        end
       end
 
       path = f.service.manual_command
@@ -140,21 +158,23 @@ describe Homebrew::Service do
 
   describe "#to_plist" do
     it "returns valid plist" do
-      f.class.service do
-        run [opt_bin/"beanstalkd", "test"]
-        run_type :immediate
-        environment_variables PATH: std_service_path_env, FOO: "BAR", ETC_DIR: etc/"beanstalkd"
-        error_log_path var/"log/beanstalkd.error.log"
-        log_path var/"log/beanstalkd.log"
-        input_path var/"in/beanstalkd"
-        root_dir var
-        working_dir var
-        keep_alive true
-        launch_only_once true
-        process_type :interactive
-        restart_delay 30
-        interval 5
-        macos_legacy_timers true
+      f = stub_formula do
+        service do
+          run [opt_bin/"beanstalkd", "test"]
+          run_type :immediate
+          environment_variables PATH: std_service_path_env, FOO: "BAR", ETC_DIR: etc/"beanstalkd"
+          error_log_path var/"log/beanstalkd.error.log"
+          log_path var/"log/beanstalkd.log"
+          input_path var/"in/beanstalkd"
+          root_dir var
+          working_dir var
+          keep_alive true
+          launch_only_once true
+          process_type :interactive
+          restart_delay 30
+          interval 5
+          macos_legacy_timers true
+        end
       end
 
       plist = f.service.to_plist
@@ -216,9 +236,11 @@ describe Homebrew::Service do
     end
 
     it "returns valid plist with socket" do
-      f.class.service do
-        run [opt_bin/"beanstalkd", "test"]
-        sockets "tcp://127.0.0.1:80"
+      f = stub_formula do
+        service do
+          run [opt_bin/"beanstalkd", "test"]
+          sockets "tcp://127.0.0.1:80"
+        end
       end
 
       plist = f.service.to_plist
@@ -265,9 +287,11 @@ describe Homebrew::Service do
     end
 
     it "returns valid partial plist" do
-      f.class.service do
-        run opt_bin/"beanstalkd"
-        run_type :immediate
+      f = stub_formula do
+        service do
+          run opt_bin/"beanstalkd"
+          run_type :immediate
+        end
       end
 
       plist = f.service.to_plist
@@ -299,10 +323,12 @@ describe Homebrew::Service do
     end
 
     it "returns valid interval plist" do
-      f.class.service do
-        run opt_bin/"beanstalkd"
-        run_type :interval
-        interval 5
+      f = stub_formula do
+        service do
+          run opt_bin/"beanstalkd"
+          run_type :interval
+          interval 5
+        end
       end
 
       plist = f.service.to_plist
@@ -336,10 +362,12 @@ describe Homebrew::Service do
     end
 
     it "returns valid cron plist" do
-      f.class.service do
-        run opt_bin/"beanstalkd"
-        run_type :cron
-        cron "@daily"
+      f = stub_formula do
+        service do
+          run opt_bin/"beanstalkd"
+          run_type :cron
+          cron "@daily"
+        end
       end
 
       plist = f.service.to_plist
@@ -378,9 +406,11 @@ describe Homebrew::Service do
     end
 
     it "returns valid keepalive-exit plist" do
-      f.class.service do
-        run opt_bin/"beanstalkd"
-        keep_alive successful_exit: false
+      f = stub_formula do
+        service do
+          run opt_bin/"beanstalkd"
+          keep_alive successful_exit: false
+        end
       end
 
       plist = f.service.to_plist
@@ -417,9 +447,11 @@ describe Homebrew::Service do
     end
 
     it "returns valid keepalive-crashed plist" do
-      f.class.service do
-        run opt_bin/"beanstalkd"
-        keep_alive crashed: true
+      f = stub_formula do
+        service do
+          run opt_bin/"beanstalkd"
+          keep_alive crashed: true
+        end
       end
 
       plist = f.service.to_plist
@@ -456,9 +488,11 @@ describe Homebrew::Service do
     end
 
     it "returns valid keepalive-path plist" do
-      f.class.service do
-        run opt_bin/"beanstalkd"
-        keep_alive path: opt_pkgshare/"test-path"
+      f = stub_formula do
+        service do
+          run opt_bin/"beanstalkd"
+          keep_alive path: opt_pkgshare/"test-path"
+        end
       end
 
       plist = f.service.to_plist
@@ -497,19 +531,21 @@ describe Homebrew::Service do
 
   describe "#to_systemd_unit" do
     it "returns valid unit" do
-      f.class.service do
-        run [opt_bin/"beanstalkd", "test"]
-        run_type :immediate
-        environment_variables PATH: std_service_path_env, FOO: "BAR"
-        error_log_path var/"log/beanstalkd.error.log"
-        log_path var/"log/beanstalkd.log"
-        input_path var/"in/beanstalkd"
-        root_dir var
-        working_dir var
-        keep_alive true
-        process_type :interactive
-        restart_delay 30
-        macos_legacy_timers true
+      f = stub_formula do
+        service do
+          run [opt_bin/"beanstalkd", "test"]
+          run_type :immediate
+          environment_variables PATH: std_service_path_env, FOO: "BAR"
+          error_log_path var/"log/beanstalkd.error.log"
+          log_path var/"log/beanstalkd.log"
+          input_path var/"in/beanstalkd"
+          root_dir var
+          working_dir var
+          keep_alive true
+          process_type :interactive
+          restart_delay 30
+          macos_legacy_timers true
+        end
       end
 
       unit = f.service.to_systemd_unit
@@ -538,10 +574,12 @@ describe Homebrew::Service do
     end
 
     it "returns valid partial oneshot unit" do
-      f.class.service do
-        run opt_bin/"beanstalkd"
-        run_type :immediate
-        launch_only_once true
+      f = stub_formula do
+        service do
+          run opt_bin/"beanstalkd"
+          run_type :immediate
+          launch_only_once true
+        end
       end
 
       unit = f.service.to_systemd_unit
@@ -562,10 +600,12 @@ describe Homebrew::Service do
 
   describe "#to_systemd_timer" do
     it "returns valid timer" do
-      f.class.service do
-        run [opt_bin/"beanstalkd", "test"]
-        run_type :interval
-        interval 5
+      f = stub_formula do
+        service do
+          run [opt_bin/"beanstalkd", "test"]
+          run_type :interval
+          interval 5
+        end
       end
 
       unit = f.service.to_systemd_timer
@@ -584,9 +624,11 @@ describe Homebrew::Service do
     end
 
     it "returns valid partial timer" do
-      f.class.service do
-        run opt_bin/"beanstalkd"
-        run_type :immediate
+      f = stub_formula do
+        service do
+          run opt_bin/"beanstalkd"
+          run_type :immediate
+        end
       end
 
       unit = f.service.to_systemd_timer
@@ -604,10 +646,12 @@ describe Homebrew::Service do
     end
 
     it "throws on incomplete cron" do
-      f.class.service do
-        run opt_bin/"beanstalkd"
-        run_type :cron
-        cron "1 2 3 4"
+      f = stub_formula do
+        service do
+          run opt_bin/"beanstalkd"
+          run_type :cron
+          cron "1 2 3 4"
+        end
       end
 
       expect {
@@ -627,10 +671,12 @@ describe Homebrew::Service do
       }
 
       styles.each do |cron, calendar|
-        f.class.service do
-          run opt_bin/"beanstalkd"
-          run_type :cron
-          cron cron.to_s
+        f = stub_formula do
+          service do
+            run opt_bin/"beanstalkd"
+            run_type :cron
+            cron cron.to_s
+          end
         end
 
         unit = f.service.to_systemd_timer
@@ -653,18 +699,22 @@ describe Homebrew::Service do
 
   describe "#timed?" do
     it "returns false for immediate" do
-      f.class.service do
-        run [opt_bin/"beanstalkd", "test"]
-        run_type :immediate
+      f = stub_formula do
+        service do
+          run [opt_bin/"beanstalkd", "test"]
+          run_type :immediate
+        end
       end
 
       expect(f.service.timed?).to be(false)
     end
 
     it "returns true for interval" do
-      f.class.service do
-        run [opt_bin/"beanstalkd", "test"]
-        run_type :interval
+      f = stub_formula do
+        service do
+          run [opt_bin/"beanstalkd", "test"]
+          run_type :interval
+        end
       end
 
       expect(f.service.timed?).to be(true)
@@ -673,35 +723,43 @@ describe Homebrew::Service do
 
   describe "#keep_alive?" do
     it "returns true when keep_alive set to hash" do
-      f.class.service do
-        run [opt_bin/"beanstalkd", "test"]
-        keep_alive crashed: true
+      f = stub_formula do
+        service do
+          run [opt_bin/"beanstalkd", "test"]
+          keep_alive crashed: true
+        end
       end
 
       expect(f.service.keep_alive?).to be(true)
     end
 
     it "returns true when keep_alive set to true" do
-      f.class.service do
-        run [opt_bin/"beanstalkd", "test"]
-        keep_alive true
+      f = stub_formula do
+        service do
+          run [opt_bin/"beanstalkd", "test"]
+          keep_alive true
+        end
       end
 
       expect(f.service.keep_alive?).to be(true)
     end
 
     it "returns false when keep_alive not set" do
-      f.class.service do
-        run [opt_bin/"beanstalkd", "test"]
+      f = stub_formula do
+        service do
+          run [opt_bin/"beanstalkd", "test"]
+        end
       end
 
       expect(f.service.keep_alive?).to be(false)
     end
 
     it "returns false when keep_alive set to false" do
-      f.class.service do
-        run [opt_bin/"beanstalkd", "test"]
-        keep_alive false
+      f = stub_formula do
+        service do
+          run [opt_bin/"beanstalkd", "test"]
+          keep_alive false
+        end
       end
 
       expect(f.service.keep_alive?).to be(false)
@@ -710,9 +768,11 @@ describe Homebrew::Service do
 
   describe "#command" do
     it "returns @run data" do
-      f.class.service do
-        run [opt_bin/"beanstalkd", "test"]
-        run_type :immediate
+      f = stub_formula do
+        service do
+          run [opt_bin/"beanstalkd", "test"]
+          run_type :immediate
+        end
       end
 
       command = f.service.command
diff --git a/Library/Homebrew/test/support/fixtures/failball.rb b/Library/Homebrew/test/support/fixtures/failball.rb
index 1b396a721e..4995d94f55 100644
--- a/Library/Homebrew/test/support/fixtures/failball.rb
+++ b/Library/Homebrew/test/support/fixtures/failball.rb
@@ -4,13 +4,22 @@
 class Failball < Formula
   def initialize(name = "failball", path = Pathname.new(__FILE__).expand_path, spec = :stable,
                  alias_path: nil, force_bottle: false)
-    self.class.instance_eval do
-      stable.url "file://#{TEST_FIXTURE_DIR}/tarballs/testball-0.1.tbz"
-      stable.sha256 TESTBALL_SHA256
-    end
     super
   end
 
+  DSL_PROC = proc do
+    url "file://#{TEST_FIXTURE_DIR}/tarballs/testball-0.1.tbz"
+    sha256 TESTBALL_SHA256
+  end.freeze
+  private_constant :DSL_PROC
+
+  DSL_PROC.call
+
+  def self.inherited(other)
+    super
+    other.instance_eval(&DSL_PROC)
+  end
+
   def install
     prefix.install "bin"
     prefix.install "libexec"
diff --git a/Library/Homebrew/test/support/fixtures/testball.rb b/Library/Homebrew/test/support/fixtures/testball.rb
index 1a99de2914..a2f23923a0 100644
--- a/Library/Homebrew/test/support/fixtures/testball.rb
+++ b/Library/Homebrew/test/support/fixtures/testball.rb
@@ -4,13 +4,22 @@
 class Testball < Formula
   def initialize(name = "testball", path = Pathname.new(__FILE__).expand_path, spec = :stable,
                  alias_path: nil, force_bottle: false)
-    self.class.instance_eval do
-      stable.url "file://#{TEST_FIXTURE_DIR}/tarballs/testball-0.1.tbz"
-      stable.sha256 TESTBALL_SHA256
-    end
     super
   end
 
+  DSL_PROC = proc do
+    url "file://#{TEST_FIXTURE_DIR}/tarballs/testball-0.1.tbz"
+    sha256 TESTBALL_SHA256
+  end.freeze
+  private_constant :DSL_PROC
+
+  DSL_PROC.call
+
+  def self.inherited(other)
+    super
+    other.instance_eval(&DSL_PROC)
+  end
+
   def install
     prefix.install "bin"
     prefix.install "libexec"
diff --git a/Library/Homebrew/test/support/fixtures/testball_bottle.rb b/Library/Homebrew/test/support/fixtures/testball_bottle.rb
index d6b777996a..33d4093ef9 100644
--- a/Library/Homebrew/test/support/fixtures/testball_bottle.rb
+++ b/Library/Homebrew/test/support/fixtures/testball_bottle.rb
@@ -4,18 +4,29 @@
 class TestballBottle < Formula
   def initialize(name = "testball_bottle", path = Pathname.new(__FILE__).expand_path, spec = :stable,
                  alias_path: nil, force_bottle: false)
-    self.class.instance_eval do
-      stable.url "file://#{TEST_FIXTURE_DIR}/tarballs/testball-0.1.tbz"
-      stable.sha256 TESTBALL_SHA256
-      stable.bottle do
-        root_url "file://#{TEST_FIXTURE_DIR}/bottles"
-        sha256 cellar: :any_skip_relocation, Utils::Bottles.tag.to_sym => "8f9aecd233463da6a4ea55f5f88fc5841718c013f3e2a7941350d6130f1dc149"
-      end
-      cxxstdlib_check :skip
-    end
     super
   end
 
+  DSL_PROC = proc do
+    url "file://#{TEST_FIXTURE_DIR}/tarballs/testball-0.1.tbz"
+    sha256 TESTBALL_SHA256
+
+    bottle do
+      root_url "file://#{TEST_FIXTURE_DIR}/bottles"
+      sha256 cellar: :any_skip_relocation, Utils::Bottles.tag.to_sym => "8f9aecd233463da6a4ea55f5f88fc5841718c013f3e2a7941350d6130f1dc149"
+    end
+
+    cxxstdlib_check :skip
+  end.freeze
+  private_constant :DSL_PROC
+
+  DSL_PROC.call
+
+  def self.inherited(other)
+    super
+    other.instance_eval(&DSL_PROC)
+  end
+
   def install
     prefix.install "bin"
     prefix.install "libexec"
diff --git a/Library/Homebrew/test/support/fixtures/testball_bottle_cellar.rb b/Library/Homebrew/test/support/fixtures/testball_bottle_cellar.rb
index 58bd8edfeb..85ea087b19 100644
--- a/Library/Homebrew/test/support/fixtures/testball_bottle_cellar.rb
+++ b/Library/Homebrew/test/support/fixtures/testball_bottle_cellar.rb
@@ -4,19 +4,29 @@
 class TestballBottleCellar < Formula
   def initialize(name = "testball_bottle", path = Pathname.new(__FILE__).expand_path, spec = :stable,
                  alias_path: nil, force_bottle: false)
-    self.class.instance_eval do
-      stable.url "file://#{TEST_FIXTURE_DIR}/tarballs/testball-0.1.tbz"
-      stable.sha256 TESTBALL_SHA256
-      hexdigest = "8f9aecd233463da6a4ea55f5f88fc5841718c013f3e2a7941350d6130f1dc149"
-      stable.bottle do
-        root_url "file://#{TEST_FIXTURE_DIR}/bottles"
-        sha256 cellar: :any_skip_relocation, Utils::Bottles.tag.to_sym => hexdigest
-      end
-      cxxstdlib_check :skip
-    end
     super
   end
 
+  DSL_PROC = proc do
+    url "file://#{TEST_FIXTURE_DIR}/tarballs/testball-0.1.tbz"
+    sha256 TESTBALL_SHA256
+
+    bottle do
+      root_url "file://#{TEST_FIXTURE_DIR}/bottles"
+      sha256 cellar: :any_skip_relocation, Utils::Bottles.tag.to_sym => "8f9aecd233463da6a4ea55f5f88fc5841718c013f3e2a7941350d6130f1dc149"
+    end
+
+    cxxstdlib_check :skip
+  end.freeze
+  private_constant :DSL_PROC
+
+  DSL_PROC.call
+
+  def self.inherited(other)
+    super
+    other.instance_eval(&DSL_PROC)
+  end
+
   def install
     prefix.install "bin"
     prefix.install "libexec"