Fix: Don't send content-type header when file has extension

Modified ParseXFile and ParseFile to only send content-type: application/octet-stream when the filename has no extension. When a file extension exists, the server will infer the correct MIME type from the extension, fixing the issue where images were incorrectly saved as application/octet-stream.

Co-authored-by: mtrezza <5673677+mtrezza@users.noreply.github.com>

Author: Copilot

packages/dart/lib/src/objects/parse_file.dart

@@ -77,11 +77,18 @@ class ParseFile extends ParseFileBase {
     _cancelToken = CancelToken();
 
     final Map<String, String> headers = <String, String>{
-      HttpHeaders.contentTypeHeader:
-          lookupMimeType(file!.path) ?? 'application/octet-stream',
       HttpHeaders.contentLengthHeader: '${file!.lengthSync()}',
     };
 
+    // Only set content-type if the file has no extension
+    // If extension exists, let the server infer the MIME type from the filename
+    final bool hasExtension = path.extension(name).isNotEmpty;
+
+    if (!hasExtension) {
+      // No extension, set content-type to application/octet-stream as fallback
+      headers[HttpHeaders.contentTypeHeader] = 'application/octet-stream';
+    }
+
     try {
       final String uri = ParseCoreData().serverUrl + _path;
       final ParseNetworkResponse response = await _client.postBytes(

packages/dart/lib/src/objects/parse_x_file.dart

@@ -92,21 +92,19 @@ class ParseXFile extends ParseFileBase {
     progressCallback ??= _progressCallback;
 
     _cancelToken = CancelToken();
-    Map<String, String> headers;
-    if (parseIsWeb) {
-      headers = <String, String>{
-        HttpHeaders.contentTypeHeader: file?.mimeType ??
-            lookupMimeType(url ?? file?.name ?? name,
-                headerBytes: await file?.readAsBytes()) ??
-            'application/octet-stream',
-      };
-    } else {
-      headers = <String, String>{
-        HttpHeaders.contentTypeHeader: file?.mimeType ??
-            lookupMimeType(file!.path) ??
-            'application/octet-stream',
-        HttpHeaders.contentLengthHeader: '${await file!.length()}',
-      };
+    Map<String, String> headers = <String, String>{};
+
+    // Only set content-type if the file has no extension
+    // If extension exists, let the server infer the MIME type from the filename
+    final bool hasExtension = path.extension(name).isNotEmpty;
+
+    if (!hasExtension) {
+      // No extension, set content-type to application/octet-stream as fallback
+      headers[HttpHeaders.contentTypeHeader] = 'application/octet-stream';
+    }
+
+    if (!parseIsWeb) {
+      headers[HttpHeaders.contentLengthHeader] = '${await file!.length()}';
     }
 
     try {