webpack/lib/util/buildDiagnostics.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 Haijie Xie @hai-x
*/

"use strict";

/** @import Module, { BuildDiagnostics, BuildInfo } from "../Module" */
/** @import ModuleGraph from "../ModuleGraph" */

/**
 * The diagnostics record of a build info, created on first use so a module nothing reports about carries none.
 * @param {BuildInfo} buildInfo the build info of the module
 * @returns {BuildDiagnostics} the record
 */
const getBuildDiagnostics = (buildInfo) => {
	let diagnostics = buildInfo.diagnostics;
	if (diagnostics === undefined) {
		diagnostics = buildInfo.diagnostics = {
			optimizationBailouts: undefined,
			sideEffectStatement: undefined,
			ineffectivePureAnnotations: undefined,
			topLevelThis: undefined,
			usesEval: undefined,
			notCacheableReasons: undefined
		};
	}
	return diagnostics;
};

/**
 * Records a bailout a parser plugin found, where a module restored from the cache still has it for the module graph to report.
 * @param {BuildInfo} buildInfo the build info of the module being parsed
 * @param {string} reason the bailout as reported
 * @returns {void}
 */
const recordOptimizationBailout = (buildInfo, reason) => {
	const diagnostics = getBuildDiagnostics(buildInfo);
	const bailouts =
		diagnostics.optimizationBailouts || (diagnostics.optimizationBailouts = []);
	bailouts.push(reason);
};

/**
 * Replays the bailouts parser plugins recorded for a module into the module graph,
 * which a module reused from the cache never parses into.
 * @param {ModuleGraph} moduleGraph the module graph
 * @param {Module} module the built or still valid module
 * @returns {void}
 */
const replayOptimizationBailouts = (moduleGraph, module) => {
	const buildInfo = module.buildInfo;
	if (buildInfo === undefined) return;
	const diagnostics = buildInfo.diagnostics;
	if (
		diagnostics === undefined ||
		diagnostics.optimizationBailouts === undefined
	) {
		return;
	}
	const bailouts = moduleGraph.getOptimizationBailout(module);
	for (const reason of diagnostics.optimizationBailouts) bailouts.push(reason);
};

module.exports = {
	getBuildDiagnostics,
	recordOptimizationBailout,
	replayOptimizationBailouts
};