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app_vue/node_modules/watchpack/lib/LinkResolver.js

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+/*
+	MIT License http://www.opensource.org/licenses/mit-license.php
+	Author Tobias Koppers @sokra
+*/
+"use strict";
+
+const fs = require("fs");
+const path = require("path");
+
+// macOS, Linux, and Windows all rely on these errors
+const EXPECTED_ERRORS = new Set(["EINVAL", "ENOENT"]);
+
+// On Windows there is also this error in some cases
+if (process.platform === "win32") EXPECTED_ERRORS.add("UNKNOWN");
+
+class LinkResolver {
+	constructor() {
+		this.cache = new Map();
+	}
+
+	/**
+	 * @param {string} file path to file or directory
+	 * @returns {string[]} array of file and all symlinks contributed in the resolving process (first item is the resolved file)
+	 */
+	resolve(file) {
+		const cacheEntry = this.cache.get(file);
+		if (cacheEntry !== undefined) {
+			return cacheEntry;
+		}
+		const parent = path.dirname(file);
+		if (parent === file) {
+			// At root of filesystem there can't be a link
+			const result = Object.freeze([file]);
+			this.cache.set(file, result);
+			return result;
+		}
+		// resolve the parent directory to find links there and get the real path
+		const parentResolved = this.resolve(parent);
+		let realFile = file;
+
+		// is the parent directory really somewhere else?
+		if (parentResolved[0] !== parent) {
+			// get the real location of file
+			const basename = path.basename(file);
+			realFile = path.resolve(parentResolved[0], basename);
+		}
+		// try to read the link content
+		try {
+			const linkContent = fs.readlinkSync(realFile);
+
+			// resolve the link content relative to the parent directory
+			const resolvedLink = path.resolve(parentResolved[0], linkContent);
+
+			// recursive resolve the link content for more links in the structure
+			const linkResolved = this.resolve(resolvedLink);
+
+			// merge parent and link resolve results
+			let result;
+			if (linkResolved.length > 1 && parentResolved.length > 1) {
+				// when both contain links we need to duplicate them with a Set
+				const resultSet = new Set(linkResolved);
+				// add the link
+				resultSet.add(realFile);
+				// add all symlinks of the parent
+				for (let i = 1; i < parentResolved.length; i++) {
+					resultSet.add(parentResolved[i]);
+				}
+				result = Object.freeze(Array.from(resultSet));
+			} else if (parentResolved.length > 1) {
+				// we have links in the parent but not for the link content location
+				result = parentResolved.slice();
+				result[0] = linkResolved[0];
+				// add the link
+				result.push(realFile);
+				Object.freeze(result);
+			} else if (linkResolved.length > 1) {
+				// we can return the link content location result
+				result = linkResolved.slice();
+				// add the link
+				result.push(realFile);
+				Object.freeze(result);
+			} else {
+				// neither link content location nor parent have links
+				// this link is the only link here
+				result = Object.freeze([
+					// the resolve real location
+					linkResolved[0],
+					// add the link
+					realFile
+				]);
+			}
+			this.cache.set(file, result);
+			return result;
+		} catch (e) {
+			if (!EXPECTED_ERRORS.has(e.code)) {
+				throw e;
+			}
+			// no link
+			const result = parentResolved.slice();
+			result[0] = realFile;
+			Object.freeze(result);
+			this.cache.set(file, result);
+			return result;
+		}
+	}
+}
+module.exports = LinkResolver;