From fb5e8d15a0db74350fe659d4a3b56fb2401b70aa Mon Sep 17 00:00:00 2001
From: Mark Skelton <mskelton@widen.com>
Date: Thu, 28 Jul 2022 09:29:57 -0500
Subject: [PATCH] Support default exports. (#8)

---
 .changeset/small-comics-rush.md | 5 +++++
 src/index.ts                    | 8 ++++++--
 test/AsyncBackend.spec.ts       | 8 ++++++++
 3 files changed, 19 insertions(+), 2 deletions(-)
 create mode 100644 .changeset/small-comics-rush.md

diff --git a/.changeset/small-comics-rush.md b/.changeset/small-comics-rush.md
new file mode 100644
index 0000000..dd5f524
--- /dev/null
+++ b/.changeset/small-comics-rush.md
@@ -0,0 +1,5 @@
+---
+'i18next-async-backend': patch
+---
+
+Support ESModule default exports.
diff --git a/src/index.ts b/src/index.ts
index d2d36e9..c3e06e0 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,6 +1,10 @@
 import { BackendModule, ReadCallback, Services } from 'i18next'
 
-type ResourceFetcher = () => Promise<Record<string, string>>
+type ResourceFetcher = () => Promise<{
+  __esModule?: true
+  default?: Record<string, unknown>
+  [key: string]: unknown
+}>
 
 export interface AsyncBackendOptions {
   resources?: {
@@ -31,7 +35,7 @@ export default class AsyncBackend
 
     if (resourceFetcher) {
       resourceFetcher()
-        .then((resource) => callback(null, resource))
+        .then((res) => callback(null, res.__esModule ? res.default : res))
         .catch((err) => callback(err, false))
     } else {
       callback(new Error('resource not found'), false)
diff --git a/test/AsyncBackend.spec.ts b/test/AsyncBackend.spec.ts
index 2585282..e161a3e 100644
--- a/test/AsyncBackend.spec.ts
+++ b/test/AsyncBackend.spec.ts
@@ -58,3 +58,11 @@ it('should load multiple languages', async () => {
   expect(t('ns1:fruit')).toBe('Manzanas')
   expect(t('ns2:fruit')).toBe('Naranjas')
 })
+
+it('should parse ESM default exports', async () => {
+  const { t } = await init(['translation'], {
+    en: () => Promise.resolve({ __esModule: true, default: { foo: 'bar' } }),
+  })
+
+  expect(t('foo')).toBe('bar')
+})