Automating open source project configuration with Mrm

Artem Sapegin

Typical open source project

1 × source code file
1 × test file
1 × documentation file
11 × support files

`.somethingrc`

.babelignore .babelrc .editorconfig .eslintignore .eslintrc .flowconfig .gitattributes .gitignore .istanbul.yml .npmignore .nvmrc .prettierignore .prettierrc .proselintrc .remarkrc .shipit .stylelintrc .textlintrc .travis.yml appveyor.yml Changelog.md Code_of_Conduct.md codecov.yml Contributing.md Issue_Template.md jsconfig.json lerna.json License.md open-bot.yaml package.json Pull_Request_Template.md Readme.md tsconfig.json

× number of your projects

Support files are slightly different in different projects

Templates are OK for bootstrapping new projects

Updates are hard

We need codemods for config files

Mrm

github.com/sapegin/mrm

Example: gitignore task

npx mrm gitignore

Example: license task

npx mrm license

Example: Jest task

npx mrm jest

Adds npm scripts
Config in package.json
.gitignore, .npmignore, .eslintignore
Installs Jest
babel-jest, ts-jest, Enzyme if needed
Removes Mocha and AVA
And more

Details

Default tasks

CodeCov, EditorConfig, ESLint, Jest, lint-staged, Prettier, semantic-release, React Styleguidist, stylelint, Travis CI, TypeScript, package.json, contributing guidelines, license and readme files

Minimal configuration

Project: dependencies
Environment: Git or npm configs

Minimal changes

Tries to keep formatting
Keep comments in JSON

Configuration

Command line:

npx mrm license --config:licenseFile README

Config file:
- ~/.mrm/config.json
- ~/dotfiles/mrm/config.json

mrm-task-<TASK>
mrm-preset-<PRESET>

Writing custom tasks

API for writing tasks — `mrm-core`

JSON, YAML, INI, new line separated text files
npm install / uninstall
File operations
EditorConfig utilities

Simplest task

const { lines } = require('mrm-core');
module.exports = () => {
  // Read .gitignore if it exists
  lines('.gitignore')
    // Add lines that do not exist in a file yet,
    // but keep all existing lines
    .add(['node_modules/', '.DS_Store'])
    // Update or create a file
    .save();
};

Configurable task

module.exports = config => {
  // npm mrm eslint --config:eslintPreset airbnb
  const { indent, eslintPreset } = config
    .defaults({
      // Default value
      eslintPreset: 'eslint:recommended'
    })
    // Required option
    .require('indent')
    .values();
  /* _ */
};

JSON files

const { json } = require('mrm-core');
module.exports = config => {
  // Read .eslintrc if it exists
  json('.eslintrc')
    // Merge content with new options
    .merge({
      parser: 'babel-eslint',
      extends: 'eslint:recommended'
    })
    .save();
};

`package.json` files

const { packageJson } = require('mrm-core');
module.exports = config => {
  // Read project’s package.json
  packageJson()
    // Add lint script
    .setScript('lint', 'eslint . --cache --fix')
    // Add pretest script
    .prependScript('pretest', 'npm run lint')
    .save();
};

npm dependencies

const { packageJson, install } = require('mrm-core');
module.exports = config => {
  const packages = ['eslint'];
  const pkg = packageJson();
  if (pkg.get('devDependencies.babel-core')) {
    packages.push('babel-eslint');
  }
  // Install npm dependencies
  install(packages);
};

And much more

github.com/sapegin/mrm-core

Thank you and automate your configs

Mrm: github.com/sapegin/mrm
Slides: bit.ly/mrm-slides
Me: sapegin.me
Twitter: @iamsapegin
GitHub: sapegin