From c8f5e511950bcf2ae6a6504430407b2ff7dfbb4f Mon Sep 17 00:00:00 2001
From: Oskar Eichler <oskar@songstats.com>
Date: Sun, 30 Aug 2026 01:45:09 +0200
Subject: [PATCH] fix(storage): decode data URLs with custom content types

---
 .../__tests__/StorageReference.test.ts        | 20 +++++++++++++++++++
 packages/storage/e2e/StorageTask.e2e.js       | 15 ++++++++++++++
 packages/storage/lib/StorageReference.ts      |  4 ++--
 3 files changed, 37 insertions(+), 2 deletions(-)
 create mode 100644 packages/storage/__tests__/StorageReference.test.ts

diff --git a/packages/storage/__tests__/StorageReference.test.ts b/packages/storage/__tests__/StorageReference.test.ts
new file mode 100644
index 0000000000..6f799118ee
--- /dev/null
+++ b/packages/storage/__tests__/StorageReference.test.ts
@@ -0,0 +1,20 @@
+import { describe, expect, it } from '@jest/globals';
+
+import Reference from '../lib/StorageReference';
+import { StringFormat } from '../lib/StorageStatics';
+import type { StorageInternal } from '../lib/types/internal';
+
+describe('StorageReference string uploads', () => {
+  it('decodes a data URL when metadata already provides a content type', () => {
+    const reference = new Reference({} as StorageInternal, '/file.txt');
+    const metadata = { contentType: 'text/custom' };
+
+    expect(
+      reference._updateString('data:text/plain;base64,aGVsbG8=', StringFormat.DATA_URL, metadata),
+    ).toEqual({
+      _format: StringFormat.BASE64,
+      _metadata: metadata,
+      _string: 'aGVsbG8=',
+    });
+  });
+});
diff --git a/packages/storage/e2e/StorageTask.e2e.js b/packages/storage/e2e/StorageTask.e2e.js
index bbd233c729..f73352986c 100644
--- a/packages/storage/e2e/StorageTask.e2e.js
+++ b/packages/storage/e2e/StorageTask.e2e.js
@@ -171,6 +171,21 @@ describe('storage() -> StorageTask', function () {
         uploadTaskSnapshot.metadata.should.be.an.Object();
       });
 
+      it('uploads a data_url with an explicit content type', async function () {
+        const { getStorage, ref, uploadString, StringFormat, TaskState } = storageModular;
+
+        const uploadTaskSnapshot = await uploadString(
+          ref(getStorage(), `${PATH}/putStringDataURLWithContentType.txt`),
+          'data:text/plain;base64,aGVsbG8=',
+          StringFormat.DATA_URL,
+          { contentType: 'text/custom' },
+        );
+
+        uploadTaskSnapshot.state.should.eql(TaskState.SUCCESS);
+        uploadTaskSnapshot.metadata.size.should.eql(5);
+        uploadTaskSnapshot.metadata.contentType.should.eql('text/custom');
+      });
+
       it('uploads a url encoded data_url formatted string', async function () {
         const { getStorage, ref, uploadString, StringFormat, TaskState } = storageModular;
 
diff --git a/packages/storage/lib/StorageReference.ts b/packages/storage/lib/StorageReference.ts
index e3f904eb2c..b3cf6f3d22 100644
--- a/packages/storage/lib/StorageReference.ts
+++ b/packages/storage/lib/StorageReference.ts
@@ -339,9 +339,9 @@ export default class Reference extends ReferenceBase implements StorageReference
           _metadata = {};
         }
         _metadata!.contentType = mediaType;
-        _string = base64String;
-        _format = StringFormat.BASE64;
       }
+      _string = base64String;
+      _format = StringFormat.BASE64;
     }
     return { _string, _metadata, _format };
   }