webpack/lib/ErrorHelpers.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 Tobias Koppers @sokra
*/

"use strict";

const loaderFlag = "LOADER_EXECUTION";

const webpackOptionsFlag = "WEBPACK_OPTIONS";

/**
 * Returns stack trace without the specified flag included.
 * @param {string} stack stack trace
 * @param {string} flag flag to cut off
 * @returns {string} stack trace without the specified flag included
 */
const cutOffByFlag = (stack, flag) => {
	const errorStack = stack.split("\n");
	for (let i = 0; i < errorStack.length; i++) {
		if (errorStack[i].includes(flag)) {
			errorStack.length = i;
		}
	}
	return errorStack.join("\n");
};

/**
 * Cut off loader execution.
 * @param {string} stack stack trace
 * @returns {string} stack trace without the loader execution flag included
 */
const cutOffLoaderExecution = (stack) => cutOffByFlag(stack, loaderFlag);

/**
 * Cut off webpack options.
 * @param {string} stack stack trace
 * @returns {string} stack trace without the webpack options flag included
 */
const cutOffWebpackOptions = (stack) => cutOffByFlag(stack, webpackOptionsFlag);

/**
 * Cut off multiline message.
 * @param {string} stack stack trace
 * @param {string} message error message
 * @returns {string} stack trace without the message included
 */
const cutOffMultilineMessage = (stack, message) => {
	const stackSplitByLines = stack.split("\n");
	const messageSplitByLines = message.split("\n");

	/** @type {string[]} */
	const result = [];

	for (const [idx, line] of stackSplitByLines.entries()) {
		if (!line.includes(messageSplitByLines[idx])) result.push(line);
	}

	return result.join("\n");
};

/**
 * Returns stack trace without the message included.
 * @param {string} stack stack trace
 * @param {string} message error message
 * @returns {string} stack trace without the message included
 */
const cutOffMessage = (stack, message) => {
	const nextLine = stack.indexOf("\n");
	if (nextLine === -1) {
		return stack === message ? "" : stack;
	}
	const firstLine = stack.slice(0, nextLine);
	return firstLine === message ? stack.slice(nextLine + 1) : stack;
};

/**
 * Returns stack trace without the loader execution flag and message included.
 * @param {string} stack stack trace
 * @param {string} message error message
 * @returns {string} stack trace without the loader execution flag and message included
 */
const cleanUp = (stack, message) => {
	stack = cutOffLoaderExecution(stack);
	stack = cutOffMessage(stack, message);
	return stack;
};

/**
 * Clean up webpack options.
 * @param {string} stack stack trace
 * @param {string} message error message
 * @returns {string} stack trace without the webpack options flag and message included
 */
const cleanUpWebpackOptions = (stack, message) => {
	stack = cutOffWebpackOptions(stack);
	stack = cutOffMultilineMessage(stack, message);
	return stack;
};

module.exports.cleanUp = cleanUp;
module.exports.cleanUpWebpackOptions = cleanUpWebpackOptions;
module.exports.cutOffByFlag = cutOffByFlag;
module.exports.cutOffLoaderExecution = cutOffLoaderExecution;
module.exports.cutOffMessage = cutOffMessage;
module.exports.cutOffMultilineMessage = cutOffMultilineMessage;
module.exports.cutOffWebpackOptions = cutOffWebpackOptions;