Add Pronto pre-commit hook

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## master
 
+* Add [`Pronto`](https://github.com/mmozuras/pronto) pre-commit hook
 * Add [`hadolint`](https://github.com/lukasmartinelli/hadolint) pre-commit hook
 * Use the `core.hooksPath` Git configuration option when installing hooks
 

config/default.yml

@@ -430,6 +430,13 @@ PreCommit:
     install_command: 'pip install pep8'
     include: '**/*.py'
 
+  Pronto:
+    enabled: false
+    description: 'Analyzing with pronto'
+    required_executable: 'pronto'
+    install_command: 'gem install pronto'
+    flags: ['run', '--staged --exit-code']
+
   PuppetLint:
     enabled: false
     description: 'Analyze with puppet-lint'

lib/overcommit/hook/pre_commit/pronto.rb

@@ -0,0 +1,21 @@
+module Overcommit::Hook::PreCommit
+  # Runs `pronto`
+  #
+  # @see https://github.com/mmozuras/pronto
+  class Pronto < Base
+    MESSAGE_TYPE_CATEGORIZER = lambda do |type|
+      type.include?('E') ? :error : :warning
+    end
+
+    def run
+      result = execute(command)
+      return :pass if result.success?
+
+      extract_messages(
+        result.stdout.split("\n"),
+        /^(?<file>(?:\w:)?[^:]+):(?<line>\d+) (?<type>[^ ]+)/,
+        MESSAGE_TYPE_CATEGORIZER,
+      )
+    end
+  end
+end

spec/overcommit/hook/pre_commit/pronto_spec.rb

@@ -0,0 +1,51 @@
+require 'spec_helper'
+
+describe Overcommit::Hook::PreCommit::Pronto do
+  let(:config)  { Overcommit::ConfigurationLoader.default_configuration }
+  let(:context) { double('context') }
+  subject { described_class.new(config, context) }
+
+  before do
+    subject.stub(:applicable_files).and_return(%w[file1.rb file2.rb])
+  end
+
+  context 'when pronto exits successfully' do
+    before do
+      result = double('result')
+      result.stub(:success?).and_return(true)
+      subject.stub(:execute).and_return(result)
+    end
+
+    it { should pass }
+  end
+
+  context 'when pronto exits unsucessfully' do
+    let(:result) { double('result') }
+
+    before do
+      result.stub(:success?).and_return(false)
+      subject.stub(:execute).and_return(result)
+    end
+
+    context 'and it reports an error' do
+      before do
+        result.stub(:stdout).and_return([
+          'file2.rb:10 E: IDENTICAL code found in :iter.',
+        ].join("\n"))
+      end
+
+      it { should fail_hook }
+    end
+
+    context 'and it reports a warning' do
+      before do
+        result.stub(:stdout).and_return([
+          'file1.rb:12 W: Line is too long. [107/80]',
+          'file2.rb:14 I: Prefer single-quoted strings'
+        ].join("\n"))
+      end
+
+      it { should warn }
+    end
+  end
+end