Refactor brew cask style.

Library/Homebrew/cask/cmd/style.rb

@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+require "json"
+
 module Cask
   class Cmd
     class Style < AbstractCommand
@@ -7,26 +9,50 @@ module Cask
         "checks Cask style using RuboCop"
       end
 
+      def self.rubocop(*paths, auto_correct: false, debug: false, json: false)
+        Homebrew.install_bundler_gems!
+
+        cache_env = { "XDG_CACHE_HOME" => "#{HOMEBREW_CACHE}/style" }
+        hide_warnings = debug ? [] : [ENV["HOMEBREW_RUBY_PATH"], "-W0", "-S"]
+
+        args = [
+          "--force-exclusion",
+          "--config", "#{HOMEBREW_LIBRARY}/.rubocop_cask.yml"
+        ]
+
+        if json
+          args << "--format" << "json"
+        else
+          if auto_correct
+            args << "--auto-correct"
+          else
+            args << "--debug" if debug
+            args << "--parallel"
+          end
+
+          args << "--format" << "simple"
+          args << "--color" if Tty.color?
+        end
+
+        executable, *args = [*hide_warnings, "rubocop", *args, "--", *paths]
+
+        result = Dir.mktmpdir do |tmpdir|
+          system_command executable, args: args, chdir: tmpdir, env: cache_env,
+                                     print_stdout: !json, print_stderr: !json
+        end
+
+        result.assert_success! unless (0..1).cover?(result.exit_status)
+
+        return JSON.parse(result.stdout) if json
+
+        result
+      end
+
       option "--fix", :fix, false
 
       def run
-        install_rubocop
-        cache_env = { "XDG_CACHE_HOME" => "#{HOMEBREW_CACHE}/style" }
-        hide_warnings = debug? ? [] : [ENV["HOMEBREW_RUBY_PATH"], "-W0", "-S"]
-        Dir.mktmpdir do |tmpdir|
-          system(cache_env, *hide_warnings, "rubocop", *rubocop_args, "--", *cask_paths, chdir: tmpdir)
-        end
-        raise CaskError, "style check failed" unless $CHILD_STATUS.success?
-      end
-
-      def install_rubocop
-        capture_stderr do
-          begin
-            Homebrew.install_bundler_gems!
-          rescue SystemExit
-            raise CaskError, Tty.strip_ansi($stderr.string).chomp.sub(/\AError: /, "")
-          end
-        end
+        result = self.class.rubocop(*cask_paths, auto_correct: fix?, debug: debug?)
+        raise CaskError, "Style check failed." unless result.status.success?
       end
 
       def cask_paths
@@ -39,32 +65,12 @@ module Cask
         end
       end
 
-      def rubocop_args
-        fix? ? autocorrect_args : normal_args
-      end
-
-      def default_args
-        [
-          "--force-exclusion",
-          "--config", "#{HOMEBREW_LIBRARY}/.rubocop_cask.yml",
-          "--format", "simple"
-        ]
-      end
-
       def test_cask_paths
         [
           Pathname.new("#{HOMEBREW_LIBRARY}/Homebrew/test/support/fixtures/cask/Casks"),
           Pathname.new("#{HOMEBREW_LIBRARY}/Homebrew/test/support/fixtures/third-party/Casks"),
         ]
       end
-
-      def normal_args
-        default_args + ["--parallel"]
-      end
-
-      def autocorrect_args
-        default_args + ["--auto-correct"]
-      end
     end
   end
 end

Library/Homebrew/test/cask/cmd/style_spec.rb

@@ -11,58 +11,6 @@ describe Cask::Cmd::Style, :cask do
 
   it_behaves_like "a command that handles invalid options"
 
-  describe "#run" do
-    subject { cli.run }
-
-    before do
-      allow(cli).to receive_messages(install_rubocop: nil,
-                                     system:          nil,
-                                     rubocop_args:    nil,
-                                     cask_paths:      nil)
-      allow($CHILD_STATUS).to receive(:success?).and_return(success)
-    end
-
-    context "when rubocop succeeds" do
-      let(:success) { true }
-
-      it "does not raise an error" do
-        expect { subject }.not_to raise_error
-      end
-    end
-
-    context "when rubocop fails" do
-      let(:success) { false }
-
-      it "raises an error" do
-        expect { subject }.to raise_error(Cask::CaskError)
-      end
-    end
-  end
-
-  describe "#install_rubocop" do
-    subject { cli.install_rubocop }
-
-    context "when installation succeeds" do
-      before do
-        allow(Homebrew).to receive(:install_bundler_gems!)
-      end
-
-      it "exits successfully" do
-        expect { subject }.not_to raise_error
-      end
-    end
-
-    context "when installation fails" do
-      before do
-        allow(Homebrew).to receive(:install_bundler_gems!).and_raise(SystemExit)
-      end
-
-      it "raises an error" do
-        expect { subject }.to raise_error(Cask::CaskError)
-      end
-    end
-  end
-
   describe "#cask_paths" do
     subject { cli.cask_paths }
 
@@ -117,41 +65,4 @@ describe Cask::Cmd::Style, :cask do
       end
     end
   end
-
-  describe "#rubocop_args" do
-    subject { cli.rubocop_args }
-
-    before do
-      allow(cli).to receive(:fix?).and_return(fix)
-    end
-
-    context "when fix? is true" do
-      let(:fix) { true }
-
-      it { is_expected.to include("--auto-correct") }
-    end
-
-    context "when fix? is false" do
-      let(:fix) { false }
-
-      it { is_expected.not_to include("--auto-correct") }
-    end
-  end
-
-  describe "#default_args" do
-    subject { cli.default_args }
-
-    it { is_expected.to include("--format", "simple") }
-  end
-
-  describe "#autocorrect_args" do
-    subject { cli.autocorrect_args }
-
-    let(:default_args) { ["--format", "simple"] }
-
-    it "adds --auto-correct to default args" do
-      allow(cli).to receive(:default_args).and_return(default_args)
-      expect(subject).to include("--auto-correct", *default_args)
-    end
-  end
 end