[release/8.0] Update HttpClientJsonExtensions.Get.AsyncEnumerable.cs (#92199)

* Update HttpClientJsonExtensions.Get.AsyncEnumerable.cs

reuse method from ReadFromJsonAsAsyncEnumerable

* fix trailing space

* feat: add test case

* Update HttpClientJsonExtensions.Get.AsyncEnumerable.cs

add httpClient null check

* Update HttpClientJsonExtensions.Get.AsyncEnumerable.cs

fix trailing space style

* Update src/libraries/System.Net.Http.Json/tests/FunctionalTests/HttpClientJsonExtensionsTests.cs

Co-authored-by: Eirik Tsarpalis <[email protected]>

* refine updates

---------

Co-authored-by: Weihan Li <[email protected]>
Co-authored-by: Eirik Tsarpalis <[email protected]>

Author: 3 people

src/libraries/System.Net.Http.Json/src/System/Net/Http/Json/HttpClientJsonExtensions.Get.AsyncEnumerable.cs

@@ -135,10 +135,7 @@ public static partial class HttpClientJsonExtensions
             JsonSerializerOptions? options,
             CancellationToken cancellationToken)
         {
-            options ??= JsonSerializerOptions.Default;
-            options.MakeReadOnly();
-
-            var jsonTypeInfo = (JsonTypeInfo<TValue>)options.GetTypeInfo(typeof(TValue));
+            var jsonTypeInfo = (JsonTypeInfo<TValue>)JsonHelpers.GetJsonTypeInfo(typeof(TValue), options);
 
             return FromJsonStreamAsyncCore(client, requestUri, jsonTypeInfo, cancellationToken);
         }

src/libraries/System.Net.Http.Json/tests/FunctionalTests/HttpClientJsonExtensionsTests.cs

@@ -580,6 +580,43 @@ public async Task GetFromJsonAsAsyncEnumerable_EnforcesTimeoutOnInitialRequest()
                 await Task.Delay(TimeSpan.FromMilliseconds(10));
             }
         }
+
+        [Fact]
+        public async Task GetFromJsonAsAsyncEnumerable_SerializerUsesCamelCase()
+        {
+            using var client = new HttpClient(new CustomResponseHandler((r, c) =>
+            {
+                string json = """[{"value":1},{"value":2}]""";
+                HttpResponseMessage response = new()
+                {
+                    Content = new StringContent(json)
+                };
+                return Task.FromResult(response);
+            }));
+
+            await foreach (var m in client.GetFromJsonAsAsyncEnumerable<TestModel>("http://dummyUrl"))
+            {
+                Assert.True(m.Value > 0);
+            }
+        }
+
+        [Fact]
+        public async Task GetFromJsonAsAsyncEnumerable_CustomSerializerOptions()
+        {
+            using var client = new HttpClient(new CustomResponseHandler((r, c) =>
+            {
+                string json = """[{"Value":1},{"Value":2}]""";
+                HttpResponseMessage response = new()
+                {
+                    Content = new StringContent(json)
+                };
+                return Task.FromResult(response);
+            }));
+            await foreach (var m in client.GetFromJsonAsAsyncEnumerable<TestModel>("http://dummyUrl", JsonSerializerOptions.Default))
+            {
+                Assert.True(m.Value > 0);
+            }
+        }
     }
 }
 
@@ -593,3 +630,8 @@ public CustomResponseHandler(
     protected override Task<HttpResponseMessage> SendAsync(
         HttpRequestMessage request, CancellationToken cancellationToken) => _func(request, cancellationToken);
 }
+
+file sealed class TestModel
+{
+    public int Value { get; set; }
+}