Add only_git_changes option

This allows the users to setup the project to only spellcheck files that are tracked by git when using the run_all command.

Author: Guillaume Loubier

lib/guard/codespell.rb

@@ -35,6 +35,7 @@ def start
     # @return [Object] the task result
     def run_all
       return warn_codespell_missing unless codespell
+      return run_codespell(changed_files) if options[:only_git_changes]
 
       run_codespell
     end
@@ -66,8 +67,9 @@ def run_on_modifications(paths)
     def run_codespell(paths = [])
       Guard::Compat::UI.info "Looking for typos with codespell"
       cmd = build_command(paths)
-      Guard::Compat::UI.info "... running #{cmd}"
+      Guard::Compat::UI.info "... running #{cmd}" if options[:debug]
       system(cmd)
+      Guard::Compat::UI.info "Codespell check finished"
     end
 
     def build_command(paths)
@@ -95,5 +97,12 @@ def warn_codespell_missing
       Guard::Compat::UI.warning "Spellcheck failed - guard-codespell cannot find the codespell library."
       Guard::Compat::UI.warning "Please run `pip install codespell` to resolve this issue."
     end
+
+    # Fetch a list of changed files from the result of git status
+    def changed_files
+      `git status --porcelain`.lines.map do |line|
+        line.chomp.split("  ").last
+      end
+    end
   end
 end

spec/guard/codespell_spec.rb

@@ -4,9 +4,10 @@
 require "guard/codespell"
 
 RSpec.describe Guard::Codespell do
-  subject(:guard) { described_class.new({}) }
+  subject(:guard) { described_class.new(options) }
 
   let(:paths) { %w[path/to/foo.rb path/to/bar/baz.js] }
+  let(:options) { {} }
 
   before do
     allow(guard).to receive(:run_codespell)
@@ -39,6 +40,17 @@
         guard.run_all
         expect(guard).to have_received(:run_codespell).with(no_args)
       end
+
+      context "when only_git_changes option is set to true" do
+        let(:options) { { only_git_changes: true } }
+
+        it "calls run_codespell without any args" do
+          allow(guard).to receive(:changed_files).and_return(paths)
+
+          guard.run_all
+          expect(guard).to have_received(:run_codespell).with(paths)
+        end
+      end
     end
 
     describe "#run_on_additions" do