fix hash aliases

Author: vankop

lib/AliasPlugin.js

@@ -6,6 +6,7 @@
 "use strict";
 
 const forEachBail = require("./forEachBail");
+const { PathType, getType } = require("./util/path");
 
 /** @typedef {import("./Resolver")} Resolver */
 /** @typedef {import("./Resolver").ResolveRequest} ResolveRequest */
@@ -30,6 +31,25 @@ module.exports = class AliasPlugin {
 	 */
 	apply(resolver) {
 		const target = resolver.ensureHook(this.target);
+		const cache = {};
+		const getAbsolutePathWithSlashEnding = maybeAbsolutePath => {
+			if (cache[maybeAbsolutePath] === undefined) {
+				const type = getType(maybeAbsolutePath);
+				if (type === PathType.AbsolutePosix || type === PathType.AbsoluteWin) {
+					cache[maybeAbsolutePath] = resolver
+						.join(maybeAbsolutePath, "_")
+						.slice(0, -1);
+				} else {
+					cache[maybeAbsolutePath] = null;
+				}
+			}
+			return cache[maybeAbsolutePath];
+		};
+		const isSubPath = (path, maybeSubPath) => {
+			const absolutePath = getAbsolutePathWithSlashEnding(maybeSubPath);
+			if (!absolutePath) return false;
+			return path.startsWith(absolutePath);
+		};
 		resolver
 			.getHook(this.source)
 			.tapAsync("AliasPlugin", (request, resolveContext, callback) => {
@@ -42,11 +62,9 @@ module.exports = class AliasPlugin {
 						if (
 							innerRequest === item.name ||
 							(!item.onlyModule &&
-								innerRequest.startsWith(
-									request.request
-										? `${item.name}/`
-										: resolver.join(item.name, "_").slice(0, -1)
-								))
+								(request.request
+									? innerRequest.startsWith(`${item.name}/`)
+									: isSubPath(innerRequest, item.name)))
 						) {
 							const remainingRequest = innerRequest.substr(item.name.length);
 							const resolveWithAlias = (alias, callback) => {

test/alias.js

@@ -39,6 +39,9 @@ describe("alias", function () {
 				recursive: "recursive/dir",
 				"/d/dir": "/c/dir",
 				"/d/index.js": "/c/index",
+				// alias configuration should work
+				"#": "/c/dir",
+				"@": "/c/dir",
 				ignored: false
 			},
 			modules: "/",