webpack/lib/performance/SizeLimitsPlugin.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 Sean Larkin @thelarkinn
*/

"use strict";

const { find } = require("../util/SetHelpers");
const AssetsOverSizeLimitWarning = require("./AssetsOverSizeLimitWarning");
const EntrypointsOverSizeLimitWarning = require("./EntrypointsOverSizeLimitWarning");
const NoAsyncChunksWarning = require("./NoAsyncChunksWarning");

/** @typedef {import("webpack-sources").Source} Source */
/** @typedef {import("../../declarations/WebpackOptions").PerformanceOptions} PerformanceOptions */
/** @typedef {import("../ChunkGroup")} ChunkGroup */
/** @typedef {import("../Compilation").Asset} Asset */
/** @typedef {import("../Compiler")} Compiler */
/** @typedef {import("../Entrypoint")} Entrypoint */
/** @typedef {import("../WebpackError")} WebpackError */

/**
 * Defines the asset details type used by this module.
 * @typedef {object} AssetDetails
 * @property {string} name
 * @property {number} size
 */

/**
 * Defines the entrypoint details type used by this module.
 * @typedef {object} EntrypointDetails
 * @property {string} name
 * @property {number} size
 * @property {string[]} files
 */

/** @type {WeakSet<Entrypoint | ChunkGroup | Source>} */
const isOverSizeLimitSet = new WeakSet();

/** @typedef {(name: Asset["name"], source: Asset["source"], assetInfo: Asset["info"]) => boolean} AssetFilter */

/** @type {AssetFilter} */
const excludeSourceMap = (name, source, info) => !info.development;

const PLUGIN_NAME = "SizeLimitsPlugin";

module.exports = class SizeLimitsPlugin {
	/**
	 * Creates an instance of SizeLimitsPlugin.
	 * @param {PerformanceOptions} options the plugin options
	 */
	constructor(options) {
		/** @type {PerformanceOptions["hints"]} */
		this.hints = options.hints;
		/** @type {number | undefined} */
		this.maxAssetSize = options.maxAssetSize;
		/** @type {number | undefined} */
		this.maxEntrypointSize = options.maxEntrypointSize;
		/** @type {AssetFilter | undefined} */
		this.assetFilter = options.assetFilter;
	}

	/**
	 * Checks whether this size limits plugin is over size limit.
	 * @param {Entrypoint | ChunkGroup | Source} thing the resource to test
	 * @returns {boolean} true if over the limit
	 */
	static isOverSizeLimit(thing) {
		return isOverSizeLimitSet.has(thing);
	}

	/**
	 * Applies the plugin by registering its hooks on the compiler.
	 * @param {Compiler} compiler the compiler instance
	 * @returns {void}
	 */
	apply(compiler) {
		const entrypointSizeLimit = this.maxEntrypointSize;
		const assetSizeLimit = this.maxAssetSize;
		const hints = this.hints;
		const assetFilter = this.assetFilter || excludeSourceMap;

		compiler.hooks.afterEmit.tap(PLUGIN_NAME, (compilation) => {
			/** @type {WebpackError[]} */
			const warnings = [];

			/**
			 * Gets entrypoint size.
			 * @param {Entrypoint} entrypoint an entrypoint
			 * @returns {number} the size of the entrypoint
			 */
			const getEntrypointSize = (entrypoint) => {
				let size = 0;
				for (const file of entrypoint.getFiles()) {
					const asset = compilation.getAsset(file);
					if (
						asset &&
						assetFilter(asset.name, asset.source, asset.info) &&
						asset.source
					) {
						size += asset.info.size || asset.source.size();
					}
				}
				return size;
			};

			/** @type {AssetDetails[]} */
			const assetsOverSizeLimit = [];
			for (const { name, source, info } of compilation.getAssets()) {
				if (!assetFilter(name, source, info) || !source) {
					continue;
				}

				const size = info.size || source.size();
				if (size > /** @type {number} */ (assetSizeLimit)) {
					assetsOverSizeLimit.push({
						name,
						size
					});
					isOverSizeLimitSet.add(source);
				}
			}

			/**
			 * Returns result.
			 * @param {Asset["name"]} name the name
			 * @returns {boolean | undefined} result
			 */
			const fileFilter = (name) => {
				const asset = compilation.getAsset(name);
				return asset && assetFilter(asset.name, asset.source, asset.info);
			};

			/** @type {EntrypointDetails[]} */
			const entrypointsOverLimit = [];
			for (const [name, entry] of compilation.entrypoints) {
				const size = getEntrypointSize(entry);

				if (size > /** @type {number} */ (entrypointSizeLimit)) {
					entrypointsOverLimit.push({
						name,
						size,
						files: entry.getFiles().filter(fileFilter)
					});
					isOverSizeLimitSet.add(entry);
				}
			}

			if (hints) {
				// 1. Individual Chunk: Size < 250kb
				// 2. Collective Initial Chunks [entrypoint] (Each Set?): Size < 250kb
				// 3. No Async Chunks
				// if !1, then 2, if !2 return
				if (assetsOverSizeLimit.length > 0) {
					warnings.push(
						new AssetsOverSizeLimitWarning(
							assetsOverSizeLimit,
							/** @type {number} */ (assetSizeLimit)
						)
					);
				}
				if (entrypointsOverLimit.length > 0) {
					warnings.push(
						new EntrypointsOverSizeLimitWarning(
							entrypointsOverLimit,
							/** @type {number} */ (entrypointSizeLimit)
						)
					);
				}

				if (warnings.length > 0) {
					const someAsyncChunk = find(
						compilation.chunks,
						(chunk) => !chunk.canBeInitial()
					);

					if (!someAsyncChunk) {
						warnings.push(new NoAsyncChunksWarning());
					}

					if (hints === "error") {
						compilation.errors.push(...warnings);
					} else {
						compilation.warnings.push(...warnings);
					}
				}
			}
		});
	}
};