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";

/**
 * @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");
};

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

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

/**
 * @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 = [];

	stackSplitByLines.forEach((line, idx) => {
		if (!line.includes(messageSplitByLines[idx])) result.push(line);
	});

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

/**
 * @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;
	} else {
		const firstLine = stack.slice(0, nextLine);
		return firstLine === message ? stack.slice(nextLine + 1) : stack;
	}
};

/**
 * @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;
};

/**
 * @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;
};

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