babel-plugin-string-minify/lib/index.js

Remove indentation from multiline template strings

'use strict';

module.exports = function babelPluginminify(babel) {
	var t = babel.types;

	return {
		visitor: {
			CallExpression: function CallExpression(path) {
				var node = path.node;

				if (t.isIdentifier(node.callee, { name: 'minify' })) {
					if (t.isTemplateLiteral(node.arguments[0])) {
						transform(node.arguments[0].quasis);
						return path.replaceWith(node.arguments[0]);
					} else if (t.isTaggedTemplateExpression(node.arguments[0])) {
						transform(node.arguments[0].quasi.quasis);
						return path.replaceWith(node.arguments[0]);
					}
				}
			},
			TaggedTemplateExpression: function TaggedTemplateExpression(path) {
				var node = path.node;

				if (t.isIdentifier(node.tag, { name: 'minify' })) {
					transform(node.quasi.quasis);
					return path.replaceWith(node.quasi);
				}
			}
		}
	};
};

function transform(quasis) {
	var elements = quasis.filter(function (element) {
		return element.type === 'TemplateElement';
	});

	rtrim(elements[elements.length - 1]);

	if (elements.length) {
		// let size = Math.min(...matches.map(value => value.length - 1));
		var pattern = new RegExp('\n[\t ]*', 'g');

		['raw', 'cooked'].forEach(function (type) {
			elements.forEach(function (element) {
				element.value[type] = element.value[type].replace(pattern, '');
			});
		});
	}

	ltrim(elements[0]);
}

function ltrim(element) {
	var pattern = /^\r?\n/;

	if (pattern.test(element.value.raw)) {
		element.value.raw = element.value.raw.replace(pattern, '');
		element.value.cooked = element.value.cooked.replace(pattern, '');
	}

	return element;
}

function rtrim(element) {
	var match = void 0;

	if (match = element.value.raw.match(/\r?\n([\t ]*)$/)) {
		var pattern = new RegExp('\r?\n[\t ]{' + match[1].length + '}$');

		element.value.raw = element.value.raw.replace(pattern, '');
		element.value.cooked = element.value.cooked.replace(pattern, '');
	}

	return element;
}