From a6b94850a1278e3d726ecbb3a4973b449960c2e0 Mon Sep 17 00:00:00 2001
From: Slava Egorov <vegorov@google.com>
Date: Mon, 26 May 2025 13:11:00 +0200
Subject: [PATCH] Fix CallOptions.mergeWith (#786)

It should have symmetric behavior.

Given `WebCallOptions a` and `CallOptions b` both `a.mergeWith(b)` and `b.mergeFrom(a)`
should return WebCallOptions.
---
 CHANGELOG.md                     |  4 +++-
 lib/src/client/call.dart         |  5 +++++
 test/client_tests/call_test.dart | 17 +++++++++++------
 3 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8a2f5e6..343e949 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,8 @@
 ## 4.1.0
-* Add a `serverInterceptors` argument to `ConnectionServer`. These interceptors are acting 
+* Add a `serverInterceptors` argument to `ConnectionServer`. These interceptors are acting
   as middleware, wrapping a `ServiceMethod` invocation.
+* Make sure that `CallOptions.mergeWith` is symmetric: given `WebCallOptions`
+  it should return `WebCallOptions`.
 
 ## 4.0.4
 
diff --git a/lib/src/client/call.dart b/lib/src/client/call.dart
index 0cf773c..fc671e0 100644
--- a/lib/src/client/call.dart
+++ b/lib/src/client/call.dart
@@ -86,6 +86,11 @@ class CallOptions {
 
   CallOptions mergedWith(CallOptions? other) {
     if (other == null) return this;
+
+    if (other is WebCallOptions) {
+      return other.mergedWith(this);
+    }
+
     final mergedMetadata = Map.of(metadata)..addAll(other.metadata);
     final mergedTimeout = other.timeout ?? timeout;
     final mergedProviders = List.of(metadataProviders)
diff --git a/test/client_tests/call_test.dart b/test/client_tests/call_test.dart
index 9ce832b..001fd89 100644
--- a/test/client_tests/call_test.dart
+++ b/test/client_tests/call_test.dart
@@ -34,15 +34,20 @@ void main() {
   });
 
   test('WebCallOptions mergeWith CallOptions returns WebCallOptions', () {
-    final options =
+    final options1 =
         WebCallOptions(bypassCorsPreflight: true, withCredentials: true);
     final metadata = {'test': '42'};
-    final mergedOptions =
-        options.mergedWith(CallOptions(metadata: metadata)) as WebCallOptions;
+    final options2 = CallOptions(metadata: metadata);
+    final mergedOptions1 = options1.mergedWith(options2) as WebCallOptions;
+    final mergedOptions2 = options2.mergedWith(options1) as WebCallOptions;
 
-    expect(mergedOptions.metadata, metadata);
-    expect(mergedOptions.bypassCorsPreflight, true);
-    expect(mergedOptions.withCredentials, true);
+    expect(mergedOptions1.metadata, metadata);
+    expect(mergedOptions1.bypassCorsPreflight, true);
+    expect(mergedOptions1.withCredentials, true);
+
+    expect(mergedOptions2.metadata, metadata);
+    expect(mergedOptions2.bypassCorsPreflight, true);
+    expect(mergedOptions2.withCredentials, true);
   });
 
   test(