babel-plugin-tag-minify.js

const MINIFIERS = {
	whitespace(str) {
		return str.replace(/[\n\s]*\n[\n\s]*/g,' ').trim();
	},
	collapse(str) {
		return str.replace(/[\n\s]*\n[\n\s]*/g,' ').trim();
	},
	trim(str) {
		return str.trim();
	}
};
MINIFIERS.removewhitespace = MINIFIERS.whitespace;
MINIFIERS.collapsewhitespace = MINIFIERS.collapse;

/**
 * ['tag-minify', { tags: 'html', minifier: 'collapse' }]
 * ['tag-minify', { tags: 'css', minifier: 'whitespace' }]
 * ['tag-minify', { tags: 'css', minifier: cssnano }
 */
export default ({ types: t }, { tags = 'css', minifier = 'collapse' } = {}) => {
	if (typeof tags==='string') tags = tags.split(/\s*,\s*/);
	const min = typeof minifier === 'string' ? MINIFIERS[minifier.toLowerCase()] : minifier;
	if (typeof min !== 'function') {
		throw Error(`babel-plugin-tag-minify: "minifier" must be a function or built-in minifier (received ${minifier})`);
	}

	return {
		visitor: {
			TaggedTemplateExpression(path) {
				if (tags.indexOf(path.node.tag.name)!==-1) {
					path.node.quasi.quasis.forEach(q => {
						q.value.raw = min(q.value.raw);
						q.value.cooked = min(q.value.cooked);
					});
				}
			}
		}
	};
}