allow string names in exports

hook.js

@@ -124,14 +124,17 @@ function createHook (meta) {
 import { register } from '${iitmURL}'
 import * as namespace from ${JSON.stringify(url)}
 const set = {}
-${exportNames.map((n) => `
-let $${n} = namespace.${n}
-export { $${n} as ${n} }
-set.${n} = (v) => {
-  $${n} = v
+${exportNames.map((n) => {
+  const variableName = 'v' + Buffer.from(n, 'utf-8').toString('hex');
+  return `
+let $${variableName} = namespace["${n}"]
+export { $${variableName} as "${n}" }
+set["${n}"] = (v) => {
+  $${variableName} = v
   return true
 }
-`).join('\n')}
+`
+}).join('\n')}
 register(${JSON.stringify(realUrl)}, namespace, set, ${JSON.stringify(specifiers.get(realUrl))})
 `
       }

test/fixtures/string-export.mjs

@@ -0,0 +1,3 @@
+export const foo = 41
+
+export { foo as "non-valid-identifier" }

test/hook/string-export.mjs

@@ -0,0 +1,15 @@
+// Unless explicitly stated otherwise all files in this repository are licensed under the Apache 2.0 License.
+//
+// This product includes software developed at Datadog (https://www.datadoghq.com/). Copyright 2021 Datadog, Inc.
+
+import Hook from '../../index.js'
+import * as stringExportMjs from '../fixtures/string-export.mjs'
+import { strictEqual } from 'assert'
+
+Hook((exports, name) => {
+  if (name.match(/fixtures\/string-export\.mjs/)) {
+    exports['non-valid-identifier'] += 1
+  }
+})
+
+strictEqual(stringExportMjs['non-valid-identifier'], 42)