1 files changed, 196 insertions, 0 deletions
diff --git a/node_modules/enhanced-resolve/lib/ImportsFieldPlugin.js b/node_modules/enhanced-resolve/lib/ImportsFieldPlugin.js
new file mode 100644
index 00000000..d1069603
--- /dev/null
+++ b/node_modules/enhanced-resolve/lib/ImportsFieldPlugin.js
@@ -0,0 +1,196 @@
+/*
+	MIT License http://www.opensource.org/licenses/mit-license.php
+	Author Ivan Kopeykin @vankop
+*/
+
+"use strict";
+
+const path = require("path");
+const DescriptionFileUtils = require("./DescriptionFileUtils");
+const forEachBail = require("./forEachBail");
+const { processImportsField } = require("./util/entrypoints");
+const { parseIdentifier } = require("./util/identifier");
+const { checkImportsExportsFieldTarget } = require("./util/path");
+
+/** @typedef {import("./Resolver")} Resolver */
+/** @typedef {import("./Resolver").JsonObject} JsonObject */
+/** @typedef {import("./Resolver").ResolveRequest} ResolveRequest */
+/** @typedef {import("./Resolver").ResolveStepHook} ResolveStepHook */
+/** @typedef {import("./util/entrypoints").FieldProcessor} FieldProcessor */
+/** @typedef {import("./util/entrypoints").ImportsField} ImportsField */
+
+const dotCode = ".".charCodeAt(0);
+
+module.exports = class ImportsFieldPlugin {
+	/**
+	 * @param {string | ResolveStepHook} source source
+	 * @param {Set<string>} conditionNames condition names
+	 * @param {string | string[]} fieldNamePath name path
+	 * @param {string | ResolveStepHook} targetFile target file
+	 * @param {string | ResolveStepHook} targetPackage target package
+	 */
+	constructor(
+		source,
+		conditionNames,
+		fieldNamePath,
+		targetFile,
+		targetPackage
+	) {
+		this.source = source;
+		this.targetFile = targetFile;
+		this.targetPackage = targetPackage;
+		this.conditionNames = conditionNames;
+		this.fieldName = fieldNamePath;
+		/** @type {WeakMap<JsonObject, FieldProcessor>} */
+		this.fieldProcessorCache = new WeakMap();
+	}
+
+	/**
+	 * @param {Resolver} resolver the resolver
+	 * @returns {void}
+	 */
+	apply(resolver) {
+		const targetFile = resolver.ensureHook(this.targetFile);
+		const targetPackage = resolver.ensureHook(this.targetPackage);
+
+		resolver
+			.getHook(this.source)
+			.tapAsync("ImportsFieldPlugin", (request, resolveContext, callback) => {
+				// When there is no description file, abort
+				if (!request.descriptionFilePath || request.request === undefined) {
+					return callback();
+				}
+
+				const remainingRequest =
+					request.request + request.query + request.fragment;
+				const importsField =
+					/** @type {ImportsField|null|undefined} */
+					(
+						DescriptionFileUtils.getField(
+							/** @type {JsonObject} */ (request.descriptionFileData),
+							this.fieldName
+						)
+					);
+				if (!importsField) return callback();
+
+				if (request.directory) {
+					return callback(
+						new Error(
+							`Resolving to directories is not possible with the imports field (request was ${remainingRequest}/)`
+						)
+					);
+				}
+
+				/** @type {string[]} */
+				let paths;
+
+				try {
+					// We attach the cache to the description file instead of the importsField value
+					// because we use a WeakMap and the importsField could be a string too.
+					// Description file is always an object when exports field can be accessed.
+					let fieldProcessor = this.fieldProcessorCache.get(
+						/** @type {JsonObject} */ (request.descriptionFileData)
+					);
+					if (fieldProcessor === undefined) {
+						fieldProcessor = processImportsField(importsField);
+						this.fieldProcessorCache.set(
+							/** @type {JsonObject} */ (request.descriptionFileData),
+							fieldProcessor
+						);
+					}
+					paths = fieldProcessor(remainingRequest, this.conditionNames);
+				} catch (/** @type {unknown} */ err) {
+					if (resolveContext.log) {
+						resolveContext.log(
+							`Imports field in ${request.descriptionFilePath} can't be processed: ${err}`
+						);
+					}
+					return callback(/** @type {Error} */ (err));
+				}
+
+				if (paths.length === 0) {
+					return callback(
+						new Error(
+							`Package import ${remainingRequest} is not imported from package ${request.descriptionFileRoot} (see imports field in ${request.descriptionFilePath})`
+						)
+					);
+				}
+
+				forEachBail(
+					paths,
+					/**
+					 * @param {string} p path
+					 * @param {(err?: null|Error, result?: null|ResolveRequest) => void} callback callback
+					 * @returns {void}
+					 */
+					(p, callback) => {
+						const parsedIdentifier = parseIdentifier(p);
+
+						if (!parsedIdentifier) return callback();
+
+						const [path_, query, fragment] = parsedIdentifier;
+
+						const error = checkImportsExportsFieldTarget(path_);
+
+						if (error) {
+							return callback(error);
+						}
+
+						switch (path_.charCodeAt(0)) {
+							// should be relative
+							case dotCode: {
+								/** @type {ResolveRequest} */
+								const obj = {
+									...request,
+									request: undefined,
+									path: path.join(
+										/** @type {string} */ (request.descriptionFileRoot),
+										path_
+									),
+									relativePath: path_,
+									query,
+									fragment
+								};
+
+								resolver.doResolve(
+									targetFile,
+									obj,
+									"using imports field: " + p,
+									resolveContext,
+									callback
+								);
+								break;
+							}
+
+							// package resolving
+							default: {
+								/** @type {ResolveRequest} */
+								const obj = {
+									...request,
+									request: path_,
+									relativePath: path_,
+									fullySpecified: true,
+									query,
+									fragment
+								};
+
+								resolver.doResolve(
+									targetPackage,
+									obj,
+									"using imports field: " + p,
+									resolveContext,
+									callback
+								);
+							}
+						}
+					},
+					/**
+					 * @param {null|Error} [err] error
+					 * @param {null|ResolveRequest} [result] result
+					 * @returns {void}
+					 */
+					(err, result) => callback(err, result || null)
+				);
+			});
+	}
+};