api: Add prevContentSha256 param to updateMessage route

Author: chrisbobbe

lib/api/route/messages.dart

@@ -275,6 +275,7 @@ Future<UpdateMessageResult> updateMessage(
   bool? sendNotificationToOldThread,
   bool? sendNotificationToNewThread,
   String? content,
+  String? prevContentSha256,
   int? streamId,
 }) {
   return connection.patch('updateMessage', UpdateMessageResult.fromJson, 'messages/$messageId', {
@@ -283,6 +284,7 @@ Future<UpdateMessageResult> updateMessage(
     if (sendNotificationToOldThread != null) 'send_notification_to_old_thread': sendNotificationToOldThread,
     if (sendNotificationToNewThread != null) 'send_notification_to_new_thread': sendNotificationToNewThread,
     if (content != null) 'content': RawParameter(content),
+    if (prevContentSha256 != null) 'prev_content_sha256': RawParameter(prevContentSha256),
     if (streamId != null) 'stream_id': streamId,
   });
 }

test/api/route/messages_test.dart

@@ -454,6 +454,7 @@ void main() {
       bool? sendNotificationToOldThread,
       bool? sendNotificationToNewThread,
       String? content,
+      String? prevContentSha256,
       int? streamId,
       required Map<String, String> expected,
     }) async {
@@ -464,15 +465,31 @@ void main() {
         sendNotificationToOldThread: sendNotificationToOldThread,
         sendNotificationToNewThread: sendNotificationToNewThread,
         content: content,
+        prevContentSha256: prevContentSha256,
         streamId: streamId,
       );
       check(connection.lastRequest).isA<http.Request>()
         ..method.equals('PATCH')
         ..url.path.equals('/api/v1/messages/$messageId')
-        ..bodyFields.deepEquals(expected);
+        ..bodyFields.deepEquals(expected)
+        ..bodyFields.length.equals(expected.length);
       return result;
     }
 
+    test('pure content change', () {
+      return FakeApiConnection.with_((connection) async {
+        connection.prepare(json: UpdateMessageResult().toJson());
+        await checkUpdateMessage(connection,
+          messageId: eg.streamMessage().id,
+          content: 'asdf',
+          prevContentSha256: '34a780ad578b997db55b260beb60b501f3e04d30ba1a51fcf43cd8dd1241780d',
+          expected: {
+            'content': 'asdf',
+            'prev_content_sha256': '34a780ad578b997db55b260beb60b501f3e04d30ba1a51fcf43cd8dd1241780d',
+          });
+      });
+    });
+
     test('topic/content change', () {
       // A separate test exercises `streamId`;
       // the API doesn't allow changing channel and content at the same time.