allow custom cmd option for rubocop

README.md

@@ -61,6 +61,9 @@ all_on_start: true     # Check all files at Guard startup.
 cli: '--rails'         # Pass arbitrary RuboCop CLI arguments.
                        # An array or string is acceptable.
                        #   default: nil
+cmd: './bin/rubocop'   # Pass custom cmd to run rubocop.
+                       #   default: rubocop
+
 hide_stdout: false     # Do not display console output (in case outputting to file).
                        #   default: false
 keep_failed: true      # Keep failed files until they pass.

lib/guard/rubocop/runner.rb

@@ -28,7 +28,7 @@ def run(paths = [])
       end
 
       def build_command(paths)
-        command = ['rubocop']
+        command = [@options[:cmd] || 'rubocop']
 
         if should_add_default_formatter_for_console?
           command.concat(%w[--format progress]) # Keep default formatter for console.

spec/guard/rubocop/runner_spec.rb

@@ -109,6 +109,22 @@
     let(:options) { { cli: %w[--debug --rails] } }
     let(:paths) { %w[file1.rb file2.rb] }
 
+    describe ':cmd option' do
+      context 'when set' do
+        let(:options) { { cmd: 'bin/rubocop' } }
+
+        it 'uses the supplied :cmd' do
+          expect(build_command[0]).to eq('bin/rubocop')
+        end
+      end
+
+      context 'when not set' do
+        it 'uses the default command' do
+          expect(build_command[0]).to eq('rubocop')
+        end
+      end
+    end
+
     context 'when :hide_stdout is not set' do
       context 'and :cli option includes formatter for console' do
         before { options[:cli] = %w[--format simple] }