webpack/lib/util/conventions.js

Packs ECMAScript/CommonJs/AMD modules for the browser. Allows you to split your codebase into multiple bundles, which can be loaded on demand. Supports loaders to preprocess files, i.e. json, jsx, es7, css, less, ... and your custom stuff.

/*
	MIT License http://www.opensource.org/licenses/mit-license.php
	Author Gengkun He @ahabhgk
*/

"use strict";

/** @typedef {import("../../declarations/WebpackOptions").CssGeneratorExportsConvention} CssGeneratorExportsConvention */

/**
 * @param {string} input input
 * @param {CssGeneratorExportsConvention | undefined} convention convention
 * @returns {string[]} results
 */
exports.cssExportConvention = (input, convention) => {
	const set = new Set();
	if (typeof convention === "function") {
		set.add(convention(input));
	} else {
		switch (convention) {
			case "camel-case": {
				set.add(input);
				set.add(exports.camelCase(input));
				break;
			}
			case "camel-case-only": {
				set.add(exports.camelCase(input));
				break;
			}
			case "dashes": {
				set.add(input);
				set.add(exports.dashesCamelCase(input));
				break;
			}
			case "dashes-only": {
				set.add(exports.dashesCamelCase(input));
				break;
			}
			case "as-is": {
				set.add(input);
				break;
			}
		}
	}
	return Array.from(set);
};

// Copy from css-loader
/**
 * @param {string} input input
 * @returns {string} result
 */
exports.dashesCamelCase = input => {
	return input.replace(/-+(\w)/g, (match, firstLetter) =>
		firstLetter.toUpperCase()
	);
};

// Copy from css-loader
/**
 * @param {string} input input
 * @returns {string} result
 */
exports.camelCase = input => {
	let result = input.trim();

	if (result.length === 0) {
		return "";
	}

	if (result.length === 1) {
		return result.toLowerCase();
	}

	const hasUpperCase = result !== result.toLowerCase();

	if (hasUpperCase) {
		result = preserveCamelCase(result);
	}

	return result
		.replace(/^[_.\- ]+/, "")
		.toLowerCase()
		.replace(/[_.\- ]+([\p{Alpha}\p{N}_]|$)/gu, (_, p1) => p1.toUpperCase())
		.replace(/\d+([\p{Alpha}\p{N}_]|$)/gu, m => m.toUpperCase());
};

// Copy from css-loader
/**
 * @param {string} string string
 * @returns {string} result
 */
const preserveCamelCase = string => {
	let result = string;
	let isLastCharLower = false;
	let isLastCharUpper = false;
	let isLastLastCharUpper = false;

	for (let i = 0; i < result.length; i++) {
		const character = result[i];

		if (isLastCharLower && /[\p{Lu}]/u.test(character)) {
			result = `${result.slice(0, i)}-${result.slice(i)}`;
			isLastCharLower = false;
			isLastLastCharUpper = isLastCharUpper;
			isLastCharUpper = true;
			i += 1;
		} else if (
			isLastCharUpper &&
			isLastLastCharUpper &&
			/[\p{Ll}]/u.test(character)
		) {
			result = `${result.slice(0, i - 1)}-${result.slice(i - 1)}`;
			isLastLastCharUpper = isLastCharUpper;
			isLastCharUpper = false;
			isLastCharLower = true;
		} else {
			isLastCharLower =
				character.toLowerCase() === character &&
				character.toUpperCase() !== character;
			isLastLastCharUpper = isLastCharUpper;
			isLastCharUpper =
				character.toUpperCase() === character &&
				character.toLowerCase() !== character;
		}
	}

	return result;
};