imagemin-pngout/index.js

pngout imagemin plugin

'use strict';
const isPng = require('is-png');
const pngout = require('pngout-bin');
const execa = require('execa');

module.exports = options => async buf => {
	options = {
		strategy: 0,
		...options
	};

	if (!Buffer.isBuffer(buf)) {
		return Promise.reject(new TypeError(`Expected a \`Buffer\`, got \`${typeof buf}\``));
	}

	if (!isPng(buf)) {
		return Promise.resolve(buf);
	}

	const args = [
		'-',
		'-',
		'-f0',
		'-y',
		'-force',
		'-q'
	];

	if (Number.isInteger(options.strategy)) {
		args.push(`-s${options.strategy}`);
	}

	try {
		const {stdout} = await execa(pngout, args, {
			encoding: null,
			input: buf
		});

		return stdout;
	} catch (error) {
		error.message = error.stderr || error.message;
		throw error;
	}
};