mrm-core

Marmot (mrm) core utils

Utilities to write codemods for config files (JSON, YAML, INI, Markdown, etc.). Can be used to make tasks for mrm.

Example

Add ESLint to your project:

const { json, lines, install } = require('mrm-core');

const defaultTest = 'echo "Error: no test specified" && exit 1';

module.exports = function(config) {
  const preset = config('preset', 'tamia');
  const packages = [
    'eslint',
    `eslint-config-${preset}`,
  ];

	// .eslintrc
	const eslintrc = json('.eslintrc');
	if (!eslintrc.get('extends').startsWith(preset)) {
		eslintrc
			.set('extends', preset)
			.save()
		;
	}

	// .eslintignore
	const eslintignore = lines('.eslintignore');
	eslintignore
		.add('node_modules')
		.save()
	;

	// package.json
	const pkg = json('package.json')
		.merge({
			scripts: {
				lint: 'eslint . --ext .js --fix',
			},
		})
	;

	// package.json: test command
	const test = pkg.get('scripts.test');
	if (!test || test === defaultTest) {
		pkg.set('scripts.test', 'npm run lint');
	}
	else if (!test.includes('lint')) {
		pkg.set('scripts.test', `npm run lint && ${test}`);
	}

	pkg.save();

	// package.json: dependencies
	install(packages);
};
module.exports.description = 'Adds ESLint with a custom preset';

Read more in mrm’s docs, and this talks is already included by default.

You can find more examples here.

You don’t have to use mrm-core with mrm, you can run this tasks from your own code:

const get = require('lodash/get');
const addEslint = require('./tasks/eslint');
const config = {
    preset: 'airbnb',
};
const getConfig = (prop, defaultValue) => get(config, prop, defaultValue);
addEslint(getConfig);

Installation

npm install --save-dev mrm-core

API

Work with files

• Do not overwrite original files, .
• All functions (except getters) can be chained.
• save() will create file if it doesn’t exist or update it with new data.
• save() will write file to disk only if the new content is different from the original file.

JSON

API:

const { json } = require('mrm-core')
const file = json('file name', { default: 'values' })
file.exists()  // File exists?
file.get()  // Return everything
file.get('key.subkey', 'default value')  // Return value with given address
file.set('key.subkey', 'value')  // Set value by given address
file.unset('key.subkey')  // Remove value by given address
file.merge({ key: value })  // Merge JSON with given object
file.save()  // Save file

Example:

json('package.json')
  .merge({
    scripts: {
      lint: 'eslint . --ext .js --fix',
    },
  })
  save()

YAML

API:

const { yaml } = require('mrm-core')
const file = yaml('file name', { default: 'values' })
file.exists()  // File exists?
file.get()  // Return everything
file.get('key.subkey', 'default value')  // Return value with given address
file.set('key.subkey', 'value')  // Set value by given address
file.unset('key.subkey')  // Remove value by given address
file.merge({ key: value })  // Merge JSON with given object
file.save()  // Save file

Example:

yaml('.travis.yml')
  .set('language', 'node_js')
  .set('node_js', [4, 6])
  .save()

INI

API:

const { ini } = require('mrm-core')
const file = ini('file name', 'comment')
file.exists()  // File exists?
file.get()  // Return everything
file.get('section name')  // Return section value
file.set('section name', { key: value })  // Set section value
file.unset('section name')  // Remove section
file.save()  // Save file

Example:

const { ini } = require('mrm-core')
ini('.editorconfig', 'editorconfig.org')
  .set('root', true)
  .set('*', {
	  indent_style: 'tab',
    end_of_line: 'lf',
  })
  .save()

Result:

# editorconfig.org
root = true

[*]
indent_style = tab
end_of_line = lf

Plain text separated by new line

API:

const { lines } = require('mrm-core')
const file = lines('file name', ['default', 'values'])
file.exists()  // File exists?
file.get()  // Return everything
file.add('new')  // Add new line
file.add(['new', 'lines'])  // Add multiple news lines
file.remove('new')  // Remove line
file.remove(['new', 'lines'])  // Remove multiple lines
file.save()  // Save file

Example:

lines('.eslintignore')
  .add('node_modules')
  .save()

Markdown

Note: use template function to create Markdown files.

API:

const { markdown } = require('mrm-core')
const file = markdown('file name')
file.exists()  // File exists?
file.get()  // Return file content
file.addBadge('image URL', 'link URL', 'alt text')  // Add a badge at the beginning of the file (below header)
file.save()  // Save file

Example:

markdown('Readme.md')
  .addBadge(
    `https://travis-ci.org/${config('github')}/${name}.svg`,
    `https://travis-ci.org/${config('github')}/${name}`,
    'Build Status'
  )
  .save()

Plain text templates

Templates use ES6 template literals syntax.

API:

const { template } = require('mrm-core')
const file = template('file name', 'template file name')
file.exists()  // File exists?
file.get()  // Return file content
file.apply({ key: 'value' })  // Replace template tags with given values
file.save()  // Save file

Example:

template('License.md', path.join(__dirname, 'License.md'))
  .apply(config(), {
    year: (new Date()).getFullYear(),
  })
  .save()

Template:

The MIT License
===============

Copyright ${year} ${name} (${url}), contributors

Permission is hereby granted, free of charge, to any person obtaining...

File system helpers

const { copyFiles, makeDirs } = require('mrm-core')
copyFiles('source dir', 'file name') // Copy file
copyFiles('source dir', ['file name 1', 'file name 2']) // Copy files
copyFiles('source dir', 'file name', { overwrite: false }) // Do not overwrite
makeDirs('dir name') // Create folder
makeDirs(['dir name 1', 'dir name 2']) // Create folders

Install Yarn/npm packages

Installs npm package(s) and saves them to package.json using Yarn (if available) or npm.

const { install } = require('mrm-core')
install('eslint') // Install to devDependencies
install(['tamia', 'lodash'], { dev: false }) // Install to dependencies

Custom error class: MrmError

Use this class to notify user about expected errors in your tasks. It will be printed without a stack trace and will abort task.

const { MrmError } = require('mrm-core')
if (!fs.existsSync('.travis.yml')) {
    throw new MrmError('Run travis task first');
}

Change log

The change log can be found on the Releases page.

Contributing

Everyone is welcome to contribute. Please take a moment to review the contributing guidelines.

Authors and license

Artem Sapegin and contributors.

MIT License, see the included License.md file.