Rubocop pre-commit check

Readme

# Installation

Put these files in your `.git/hooks` directory and make them executable.

# Changelog

## 1.2

* Check for RuboCop updates

## 1.1

* Fixed affected line detection
* Viloations are now sorted by line number

## 1.0

Initial release

pre-commit

#!/bin/sh

DIR=$(dirname $0)
echo $DIR

for f in $0.*; do
  echo $f
  if [[ -x $f ]]; then
    $f || exit $?
  fi
done

pre-commit.rubocop

#!/usr/bin/env ruby


require 'net/http'
require 'english'
require 'shellwords'
require 'tmpdir'
require 'rubocop'

def check_version
  uri = URI.parse("https://rubygems.org/api/v1/versions/rubocop/latest.json")
  data = JSON.parse(Net::HTTP.get(uri))

  if RuboCop::Version::STRING < data["version"]
    puts "A newer version of RuboCop is available!",
      "  Your version: #{RuboCop::Version::STRING}",
      "  New version: #{data["version"]}"
  end
end

RUBOCOP_CONFIG_STORE = RuboCop::ConfigStore.new

def style_violations(file_name, lines)
  Dir.mktmpdir "rubocop" do |dir|
    # Check out staged version of a file
    `git checkout-index --prefix='#{dir}/' '#{file_name}'`

    rubocop = RuboCop::Cop::Team.new(RuboCop::Cop::Cop.all, RUBOCOP_CONFIG_STORE.for(file_name))
    parsed_source = RuboCop::ProcessedSource.new(File.read("#{dir}/#{file_name}"), file_name)
    offenses = rubocop.inspect_file(parsed_source)

    offenses.select do |o|
      lines.include?(o.line) || [:error, :fatal].include?(o.severity.name)
    end.sort_by(&:line)
  end
end

def changed_files
  `git status --porcelain`.split(/\n/)
  .select { |file_name_with_status|
    ['A', 'M'].include? file_name_with_status[0]
  }
  .map { |file_name_with_status|
    file_name_with_status.shellsplit[1]
  }
  .select { |file_name|
    ['.rb', '.rake'].include? File.extname(file_name)
  }
end

def report
  @report ||= {}.tap do |offenses|
    changed_files.each do |file|
      diff = `git diff -U0 --staged '#{file}'`

      n = 0
      hunk = false
      lines = []
      diff.split("\n").each do |line|
        if m = /^@@ -\d+(,\d+)? \+(?<line>\d+)(,\d+)? @@/.match(line)
          n = m[:line].to_i
          hunk = true
        elsif /^\+/.match(line) && hunk
          lines << n
          n += 1
        end
      end

      offenses[file] = style_violations(file, lines)
    end
  end
end

check_version

if report.any?
  formatter = RuboCop::Formatter::ClangStyleFormatter.new(STDOUT)

  formatter.started(report.keys)
  report.each do |file, offenses|
    formatter.file_finished(file, offenses)
  end
  formatter.finished(report.keys)
end


# Only complain but don't block the commit
exit 0 # $CHILD_STATUS.to_s[-1].to_i