feat(protocol): add current_patch_number to PatchCheckRequest (#3702)

packages/shorebird_code_push_protocol/lib/src/messages/patch_check/patch_check_request.dart

@@ -17,6 +17,7 @@ class PatchCheckRequest {
     this.patchNumber,
     this.patchHash,
     this.clientId,
+    this.currentPatchNumber,
   });
 
   /// Converts a `Map<String, dynamic>` to a [PatchCheckRequest].
@@ -33,6 +34,7 @@ class PatchCheckRequest {
         appId: json['app_id'] as String,
         channel: json['channel'] as String,
         clientId: json['client_id'] as String?,
+        currentPatchNumber: json['current_patch_number'] as int?,
       ),
     );
   }
@@ -73,6 +75,14 @@ class PatchCheckRequest {
   /// unique per app. Optional for backward compatibility.
   final String? clientId;
 
+  /// The number of the patch currently running on the device, if any.
+  ///
+  /// Supersedes [patchNumber] for newer updater clients. Unlike
+  /// [patchNumber], this does not affect the server's response;
+  /// [patchNumber] is retained for compatibility with legacy clients that
+  /// rely on the server's short-circuit path.
+  final int? currentPatchNumber;
+
   /// Converts a [PatchCheckRequest] to a `Map<String, dynamic>`.
   Map<String, dynamic> toJson() {
     return {
@@ -84,6 +94,7 @@ class PatchCheckRequest {
       'app_id': appId,
       'channel': channel,
       'client_id': clientId,
+      'current_patch_number': currentPatchNumber,
     };
   }
 
@@ -97,6 +108,7 @@ class PatchCheckRequest {
     appId,
     channel,
     clientId,
+    currentPatchNumber,
   ]);
 
   @override
@@ -110,6 +122,7 @@ class PatchCheckRequest {
         arch == other.arch &&
         appId == other.appId &&
         channel == other.channel &&
-        clientId == other.clientId;
+        clientId == other.clientId &&
+        currentPatchNumber == other.currentPatchNumber;
   }
 }

packages/shorebird_code_push_protocol/test/src/messages/patch_check/patch_check_request_test.dart

@@ -3,8 +3,27 @@ import 'package:test/test.dart';
 
 void main() {
   group(PatchCheckRequest, () {
+    const request = PatchCheckRequest(
+      releaseVersion: '1',
+      patchNumber: 2,
+      patchHash: '3',
+      platform: ReleasePlatform.android,
+      arch: 'arm64',
+      appId: 'app_123',
+      channel: 'channel_123',
+      clientId: 'client_123',
+      currentPatchNumber: 4,
+    );
+
     test('can be (de)serialized', () {
-      const request = PatchCheckRequest(
+      expect(
+        PatchCheckRequest.fromJson(request.toJson()).toJson(),
+        equals(request.toJson()),
+      );
+    });
+
+    test('is equatable', () {
+      const copy = PatchCheckRequest(
         releaseVersion: '1',
         patchNumber: 2,
         patchHash: '3',
@@ -13,11 +32,22 @@ void main() {
         appId: 'app_123',
         channel: 'channel_123',
         clientId: 'client_123',
+        currentPatchNumber: 4,
       );
-      expect(
-        PatchCheckRequest.fromJson(request.toJson()).toJson(),
-        equals(request.toJson()),
+      const different = PatchCheckRequest(
+        releaseVersion: '1',
+        patchNumber: 2,
+        patchHash: '3',
+        platform: ReleasePlatform.android,
+        arch: 'arm64',
+        appId: 'app_123',
+        channel: 'channel_123',
+        clientId: 'client_123',
+        currentPatchNumber: 5,
       );
+
+      expect(request, equals(copy));
+      expect(request, isNot(equals(different)));
     });
   });
 }