ggit/src/commit-numstat.js

var la = require('lazy-ass')
var check = require('check-more-types')
var exec = require('./exec')

// parses date, author, message
function commitMeta (lines) {
  la(lines.length > 3, 'expected more lines', lines)

  var commit = lines[0].split(' ')[1].trim()
  var author = lines[1].split(':')[1].trim()
  // remove Date:
  var date = lines[2].substr(5).trim()
  var message = lines[4].trim()

  return {
    commit: commit,
    author: author,
    date: date,
    message: message
  }
}

/*
parses git show --numstat output, which is something like this

$ git show --numstat 46350c2
commit 46350c2c9980551d338ce1ad0d8eff7bea9713ec
Author: Gleb Bahmutov <gleb.bahmutov@gmail.com>
Date:   Mon Jan 13 19:04:06 2014 -0500

    better gruntfile

1       1       .jshintrc
54      25      Gruntfile.js
9       0       complexity.json
2       1       package.json
*/
function isValidLine (line) {
  var rex = /^\s*\d+\s+\d+[\w\W]+$/
  return line && rex.test(line)
}
la(isValidLine('1  1 time-method-call.js'))
la(isValidLine(' 1  0 README.md'))

function parseNumstat (stdout) {
  la(check.unemptyString(stdout), 'missing numstat output', stdout)
  var lines = stdout.split('\n')
  la(lines.length > 3, 'expected more lines', stdout)

  var info = commitMeta(lines)

  var k = 6
  var fileChanges = {}
  for (; k < lines.length; k += 1) {
    if (isValidLine(lines[k])) {
      var parts = lines[k].split('\t')
      var added = Number(parts[0].trim())
      var deleted = Number(parts[1].trim())
      var filename = parts[2].trim()
      fileChanges[filename] = {
        filename: filename,
        added: added,
        deleted: deleted
      }
    }
  }

  info.changes = fileChanges
  return info
}

function commitNumstat (hash) {
  la(check.unemptyString(hash), 'missing commit hash', hash)

  var cmd = 'git show --numstat ' + hash
  return exec(cmd).then(parseNumstat)
}

module.exports = commitNumstat