index.js

const dedent = require('dedent');
const wrap = require('word-wrap');
const longest = require('longest');
const rightPad = require('right-pad');

const types = require('./types.json');

const maxLineWidth = 50;
const bodyLineWidth = 72;
const divider = '\n\n';
const length = longest(Object.keys(types)).length + 1;
// rightPad should be replaced with String::padEnd when available (node 8?)
const choices = Object.keys(types).map(key => ({
  name: `${rightPad(key + ':', length)} ${types[key].description}`,
  value: key
}));


module.exports = {
  // cz is an instance of inquirer
  // see: https://github.com/SBoudrias/Inquirer.js
  prompter(cz, commit) {
    console.log(dedent`
      Line 1 will be cropped at ${maxLineWidth} characters.
      All other lines will be wrapped after ${bodyLineWidth} characters.
    `);

    // Let's ask some questions of the user
    // so that we can populate our commit
    // template.
    //
    // See inquirer.js docs for specifics.
    // You can also opt to use another input
    // collection library if you prefer.
    cz.prompt([
      {
        type: 'list',
        name: 'type',
        message: dedent`
          Select the type of change that you're committing:
        `,
        choices: choices
      }, {
        type: 'input',
        name: 'scope',
        message: dedent`
          Denote the scope of this change (seed, challenges, map, etc.):
        `
      }, {
        type: 'input',
        name: 'subject',
        message: dedent`
          Write a short, imperative tense description of the change (no issue numbers)\n  E.g. Change loop challenge format:
        `,
        validate: function(input) {
          const noIssueNumbers = /\s#?\d+\s?/g;
          return !noIssueNumbers.test(input);
        },
        filter: function(input) {
          return new Promise((resolve, reject) => {
            resolve(input.replace(/\.*$/, ""));
          });
        }
      }, {
        type: 'input',
        name: 'body',
        message: dedent`
          Give description of what changed and/or why (optional):
        `
      }, {
        type: 'input',
        name: 'breaking',
        message: dedent`
          List any breaking changes:
        `
      }, {
        type: 'input',
        name: 'issues',
        message: dedent`
          List any issue(s) closed by this change (e.g. 123, 124):
        `
      }
    ]).then(answers => {
      const wrapOptions = {
        trim: true,
        newline: '\n',
        indent: '',
        width: bodyLineWidth
      };

      // parentheses are only needed when a scope is present
      let scope = answers.scope.trim();
      scope = scope ? '(' + answers.scope.trim() + ')' : '';

      // Hard limit this subject line
      const title = answers.subject.trim().slice(0, maxLineWidth);
      const subject = title.charAt(0).toUpperCase() + title.substr(1);
      const head = `${answers.type}${scope}: ${subject}`;

      // Wrap these lines at 72 characters
      const body = wrap(answers.body, wrapOptions);

      // Auto-add closing keyword to commit message body
      const issueNums = answers.issues.match(/(\d+)/g);
      const issues = issueNums == null ?
            null :
            issueNums.map(function(x) { return "Closes #" + x; })
                     .reduce(function(acc, val) {
                         return acc + "\n" + val;
                     }, "");

      // Apply breaking change prefix, removing it if already present
      let breaking = answers.breaking.trim();
      breaking = breaking ?
        'BREAKING CHANGE: ' + breaking.replace(/^BREAKING CHANGE: /, '') :
        '';

      breaking = wrap(breaking, wrapOptions);

      // if no breaking or issues filter them out
      const footer = [ breaking, issues ].filter(Boolean).join(divider);
      commit([ head, body, footer ].join(divider));
    });
  }
};