fix: Escape key of alias to support using $ prefix (#313)

Closes #312 

(See #312 for detailed explanation)

Author: Telokis

src/normalizeOptions.js

@@ -6,6 +6,7 @@ import findBabelConfig from 'find-babel-config';
 import glob from 'glob';
 import pkgUp from 'pkg-up';
 
+import { escapeRegExp } from './utils';
 import defaultResolvePath from './resolvePath';
 
 
@@ -79,7 +80,7 @@ function normalizeRoot(optsRoot, cwd) {
 }
 
 function getAliasTarget(key, isKeyRegExp) {
-  const regExpPattern = isKeyRegExp ? key : `^${key}(/.*|)$`;
+  const regExpPattern = isKeyRegExp ? key : `^${escapeRegExp(key)}(/.*|)$`;
   return new RegExp(regExpPattern);
 }
 

src/utils.js

@@ -80,3 +80,7 @@ export function mapPathString(nodePath, state) {
 export function isImportCall(types, calleePath) {
   return types.isImport(calleePath.node.callee);
 }
+
+export function escapeRegExp(string) {
+  return string.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
+}

test/index.test.js

@@ -342,6 +342,7 @@ describe('module-resolver', () => {
             '^regexp-priority': './hit',
             'regexp-priority$': './miss',
             'regexp-priority': './miss',
+            '$src': './test/testproject/src/'
           },
         }],
       ],
@@ -466,6 +467,15 @@ describe('module-resolver', () => {
       );
     });
 
+    it('should escape regexp', () => {
+      // See https://github.com/tleunen/babel-plugin-module-resolver/issues/312
+      testWithImport(
+        '$src/app',
+        './test/testproject/src/app',
+        aliasTransformerOpts,
+      );
+    })
+
     describe('with a regular expression', () => {
       it('should support replacing parts of a path', () => {
         testWithImport(