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 */
// Copy from css-loader
/**
 * Preserve camel case.
 * @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;
};

// Copy from css-loader
/**
 * Returns result.
 * @param {string} input input
 * @returns {string} result
 */
module.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());
};

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

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