Move serializer KeyValuePair tests to dedicated file

diff --git a/src/libraries/System.Text.Json/tests/Serialization/CollectionTests/CollectionTests.Generic.Read.cs b/src/libraries/System.Text.Json/tests/Serialization/CollectionTests/CollectionTests.Generic.Read.cs
index d1cb102..3e9eae8 100644 (file)
--- a/src/libraries/System.Text.Json/tests/Serialization/CollectionTests/CollectionTests.Generic.Read.cs
+++ b/src/libraries/System.Text.Json/tests/Serialization/CollectionTests/CollectionTests.Generic.Read.cs
@@ -963,167 +963,6 @@ namespace System.Text.Json.Serialization.Tests
         }
 
         [Fact]
-        public static void ReadSimpleKeyValuePairFail()
-        {
-            // Invalid form: no Value
-            Assert.Throws<JsonException>(() => JsonSerializer.Deserialize<KeyValuePair<string, int>>(@"{""Key"": 123}"));
-
-            // Invalid form: extra property
-            Assert.Throws<JsonException>(() => JsonSerializer.Deserialize<KeyValuePair<string, int>>(@"{""Key"": ""Key"", ""Value"": 123, ""Value2"": 456}"));
-
-            // Invalid form: does not contain both Key and Value properties
-            Assert.Throws<JsonException>(() => JsonSerializer.Deserialize<KeyValuePair<string, int>>(@"{""Key"": ""Key"", ""Val"": 123"));
-        }
-
-        [Fact]
-        public static void ReadListOfKeyValuePair()
-        {
-            List<KeyValuePair<string, int>> input = JsonSerializer.Deserialize<List<KeyValuePair<string, int>>>(@"[{""Key"": ""123"", ""Value"": 123},{""Key"": ""456"", ""Value"": 456}]");
-
-            Assert.Equal(2, input.Count);
-            Assert.Equal("123", input[0].Key);
-            Assert.Equal(123, input[0].Value);
-            Assert.Equal("456", input[1].Key);
-            Assert.Equal(456, input[1].Value);
-        }
-
-        [Fact]
-        public static void ReadKeyValuePairOfList()
-        {
-            KeyValuePair<string, List<int>> input = JsonSerializer.Deserialize<KeyValuePair<string, List<int>>>(@"{""Key"":""Key"", ""Value"":[1, 2, 3]}");
-
-            Assert.Equal("Key", input.Key);
-            Assert.Equal(3, input.Value.Count);
-            Assert.Equal(1, input.Value[0]);
-            Assert.Equal(2, input.Value[1]);
-            Assert.Equal(3, input.Value[2]);
-        }
-
-        [Theory]
-        [InlineData(@"{""Key"":""Key"", ""Value"":{""Key"":1, ""Value"":2}}")]
-        [InlineData(@"{""Key"":""Key"", ""Value"":{""Value"":2, ""Key"":1}}")]
-        [InlineData(@"{""Value"":{""Key"":1, ""Value"":2}, ""Key"":""Key""}")]
-        [InlineData(@"{""Value"":{""Value"":2, ""Key"":1}, ""Key"":""Key""}")]
-        public static void ReadKeyValuePairOfKeyValuePair(string json)
-        {
-            KeyValuePair<string, KeyValuePair<int, int>> input = JsonSerializer.Deserialize<KeyValuePair<string, KeyValuePair<int, int>>>(json);
-
-            Assert.Equal("Key", input.Key);
-            Assert.Equal(1, input.Value.Key);
-            Assert.Equal(2, input.Value.Value);
-        }
-
-        [Fact]
-        public static void ReadKeyValuePairWithNullValues()
-        {
-            {
-                KeyValuePair<string, string> kvp = JsonSerializer.Deserialize<KeyValuePair<string, string>>(@"{""Key"":""key"",""Value"":null}");
-                Assert.Equal("key", kvp.Key);
-                Assert.Null(kvp.Value);
-            }
-
-            {
-                KeyValuePair<string, object> kvp = JsonSerializer.Deserialize<KeyValuePair<string, object>>(@"{""Key"":""key"",""Value"":null}");
-                Assert.Equal("key", kvp.Key);
-                Assert.Null(kvp.Value);
-            }
-
-            {
-                KeyValuePair<string, SimpleClassWithKeyValuePairs> kvp = JsonSerializer.Deserialize<KeyValuePair<string, SimpleClassWithKeyValuePairs>>(@"{""Key"":""key"",""Value"":null}");
-                Assert.Equal("key", kvp.Key);
-                Assert.Null(kvp.Value);
-            }
-
-            {
-                KeyValuePair<string, KeyValuePair<string, string>> kvp = JsonSerializer.Deserialize<KeyValuePair<string, KeyValuePair<string, string>>>(@"{""Key"":""key"",""Value"":{""Key"":""key"",""Value"":null}}");
-                Assert.Equal("key", kvp.Key);
-                Assert.Equal("key", kvp.Value.Key);
-                Assert.Null(kvp.Value.Value);
-            }
-
-            {
-                KeyValuePair<string, KeyValuePair<string, object>> kvp = JsonSerializer.Deserialize<KeyValuePair<string, KeyValuePair<string, object>>>(@"{""Key"":""key"",""Value"":{""Key"":""key"",""Value"":null}}");
-                Assert.Equal("key", kvp.Key);
-                Assert.Equal("key", kvp.Value.Key);
-                Assert.Null(kvp.Value.Value);
-            }
-
-            {
-                KeyValuePair<string, KeyValuePair<string, SimpleClassWithKeyValuePairs>> kvp = JsonSerializer.Deserialize<KeyValuePair<string, KeyValuePair<string, SimpleClassWithKeyValuePairs>>>(@"{""Key"":""key"",""Value"":{""Key"":""key"",""Value"":null}}");
-                Assert.Equal("key", kvp.Key);
-                Assert.Equal("key", kvp.Value.Key);
-                Assert.Null(kvp.Value.Value);
-            }
-        }
-
-        [Fact]
-        public static void ReadClassWithNullKeyValuePairValues()
-        {
-            string json =
-                    @"{" +
-                        @"""KvpWStrVal"":{" +
-                            @"""Key"":""key""," +
-                            @"""Value"":null" +
-                        @"}," +
-                        @"""KvpWObjVal"":{" +
-                            @"""Key"":""key""," +
-                            @"""Value"":null" +
-                        @"}," +
-                        @"""KvpWClassVal"":{" +
-                            @"""Key"":""key""," +
-                            @"""Value"":null" +
-                        @"}," +
-                        @"""KvpWStrKvpVal"":{" +
-                            @"""Key"":""key""," +
-                            @"""Value"":{" +
-                                @"""Key"":""key""," +
-                                @"""Value"":null" +
-                            @"}" +
-                        @"}," +
-                        @"""KvpWObjKvpVal"":{" +
-                            @"""Key"":""key""," +
-                            @"""Value"":{" +
-                                @"""Key"":""key""," +
-                                @"""Value"":null" +
-                            @"}" +
-                        @"}," +
-                        @"""KvpWClassKvpVal"":{" +
-                            @"""Key"":""key""," +
-                            @"""Value"":{" +
-                                @"""Key"":""key""," +
-                                @"""Value"":null" +
-                            @"}" +
-                        @"}" +
-                    @"}";
-            SimpleClassWithKeyValuePairs obj = JsonSerializer.Deserialize<SimpleClassWithKeyValuePairs>(json);
-
-            Assert.Equal("key", obj.KvpWStrVal.Key);
-            Assert.Equal("key", obj.KvpWObjVal.Key);
-            Assert.Equal("key", obj.KvpWClassVal.Key);
-            Assert.Equal("key", obj.KvpWStrKvpVal.Key);
-            Assert.Equal("key", obj.KvpWObjKvpVal.Key);
-            Assert.Equal("key", obj.KvpWClassKvpVal.Key);
-            Assert.Equal("key", obj.KvpWStrKvpVal.Value.Key);
-            Assert.Equal("key", obj.KvpWObjKvpVal.Value.Key);
-            Assert.Equal("key", obj.KvpWClassKvpVal.Value.Key);
-
-            Assert.Null(obj.KvpWStrVal.Value);
-            Assert.Null(obj.KvpWObjVal.Value);
-            Assert.Null(obj.KvpWClassVal.Value);
-            Assert.Null(obj.KvpWStrKvpVal.Value.Value);
-            Assert.Null(obj.KvpWObjKvpVal.Value.Value);
-            Assert.Null(obj.KvpWClassKvpVal.Value.Value);
-        }
-
-        [Fact]
-        public static void Kvp_NullKeyIsFine()
-        {
-            KeyValuePair<string, string> kvp = JsonSerializer.Deserialize<KeyValuePair<string, string>>(@"{""Key"":null,""Value"":null}");
-            Assert.Null(kvp.Key);
-            Assert.Null(kvp.Value);
-        }
-
-        [Fact]
         public static void ReadSimpleTestClass_GenericCollectionWrappers()
         {
             SimpleTestClassWithGenericCollectionWrappers obj = JsonSerializer.Deserialize<SimpleTestClassWithGenericCollectionWrappers>(SimpleTestClassWithGenericCollectionWrappers.s_json);

diff --git a/src/libraries/System.Text.Json/tests/Serialization/CollectionTests/CollectionTests.Generic.Write.cs b/src/libraries/System.Text.Json/tests/Serialization/CollectionTests/CollectionTests.Generic.Write.cs
index e408f09..2c2c618 100644 (file)
--- a/src/libraries/System.Text.Json/tests/Serialization/CollectionTests/CollectionTests.Generic.Write.cs
+++ b/src/libraries/System.Text.Json/tests/Serialization/CollectionTests/CollectionTests.Generic.Write.cs
@@ -751,117 +751,6 @@ namespace System.Text.Json.Serialization.Tests
         }
 
         [Fact]
-        public static void WritePrimitiveKeyValuePair()
-        {
-            KeyValuePair<string, int> input = new KeyValuePair<string, int>("Key", 123) ;
-
-            string json = JsonSerializer.Serialize(input);
-            Assert.Equal(@"{""Key"":""Key"",""Value"":123}", json);
-        }
-
-        [Fact]
-        public static void WriteListOfKeyValuePair()
-        {
-            List<KeyValuePair<string, int>> input = new List<KeyValuePair<string, int>>
-            {
-                new KeyValuePair<string, int>("123", 123),
-                new KeyValuePair<string, int>("456", 456)
-            };
-
-            string json = JsonSerializer.Serialize(input);
-            Assert.Equal(@"[{""Key"":""123"",""Value"":123},{""Key"":""456"",""Value"":456}]", json);
-        }
-
-        [Fact]
-        public static void WriteKeyValuePairOfList()
-        {
-            KeyValuePair<string, List<int>> input = new KeyValuePair<string, List<int>>("Key", new List<int> { 1, 2, 3 });
-
-            string json = JsonSerializer.Serialize(input);
-            Assert.Equal(@"{""Key"":""Key"",""Value"":[1,2,3]}", json);
-        }
-
-        [Fact]
-        public static void WriteKeyValuePairOfKeyValuePair()
-        {
-            KeyValuePair<string, KeyValuePair<string, int>> input = new KeyValuePair<string, KeyValuePair<string, int>>(
-                "Key", new KeyValuePair<string, int>("Key", 1));
-
-            string json = JsonSerializer.Serialize(input);
-            Assert.Equal(@"{""Key"":""Key"",""Value"":{""Key"":""Key"",""Value"":1}}", json);
-        }
-
-        [Fact]
-        public static void WriteKeyValuePairWithNullValues()
-        {
-            {
-                KeyValuePair<string, string> kvp = new KeyValuePair<string, string>("key", null);
-                Assert.Equal(@"{""Key"":""key"",""Value"":null}", JsonSerializer.Serialize(kvp));
-            }
-
-            {
-                KeyValuePair<string, object> kvp = new KeyValuePair<string, object>("key", null);
-                Assert.Equal(@"{""Key"":""key"",""Value"":null}", JsonSerializer.Serialize(kvp));
-            }
-
-            {
-                KeyValuePair<string, SimpleClassWithKeyValuePairs> kvp = new KeyValuePair<string, SimpleClassWithKeyValuePairs>("key", null);
-                Assert.Equal(@"{""Key"":""key"",""Value"":null}", JsonSerializer.Serialize(kvp));
-            }
-
-            {
-                KeyValuePair<string, KeyValuePair<string, string>> kvp = new KeyValuePair<string, KeyValuePair<string, string>>("key", new KeyValuePair<string, string>("key", null));
-                Assert.Equal(@"{""Key"":""key"",""Value"":{""Key"":""key"",""Value"":null}}", JsonSerializer.Serialize(kvp));
-            }
-
-            {
-                KeyValuePair<string, KeyValuePair<string, object>> kvp = new KeyValuePair<string, KeyValuePair<string, object>>("key", new KeyValuePair<string, object>("key", null));
-                Assert.Equal(@"{""Key"":""key"",""Value"":{""Key"":""key"",""Value"":null}}", JsonSerializer.Serialize(kvp));
-            }
-
-            {
-                KeyValuePair<string, KeyValuePair<string, SimpleClassWithKeyValuePairs>> kvp = new KeyValuePair<string, KeyValuePair<string, SimpleClassWithKeyValuePairs>>("key", new KeyValuePair<string, SimpleClassWithKeyValuePairs>("key", null));
-                Assert.Equal(@"{""Key"":""key"",""Value"":{""Key"":""key"",""Value"":null}}", JsonSerializer.Serialize(kvp));
-            }
-        }
-
-        // https://github.com/dotnet/runtime/issues/30388
-        [Fact]
-        public static void WriteClassWithNullKeyValuePairValues_NullWrittenAsEmptyObject()
-        {
-            var value = new SimpleClassWithKeyValuePairs()
-            {
-                KvpWStrVal = new KeyValuePair<string, string>("key", null),
-                KvpWObjVal = new KeyValuePair<string, object>("key", null),
-                KvpWClassVal = new KeyValuePair<string, SimpleClassWithKeyValuePairs>("key", null),
-                KvpWStrKvpVal = new KeyValuePair<string, KeyValuePair<string, string>>("key", new KeyValuePair<string, string>("key", null)),
-                KvpWObjKvpVal = new KeyValuePair<string, KeyValuePair<string, object>>("key", new KeyValuePair<string, object>("key", null)),
-                KvpWClassKvpVal = new KeyValuePair<string, KeyValuePair<string, SimpleClassWithKeyValuePairs>>("key", new KeyValuePair<string, SimpleClassWithKeyValuePairs>("key", null)),
-            };
-
-            string result = JsonSerializer.Serialize(value);
-
-            // Roundtrip to ensure serialize was correct.
-            value = JsonSerializer.Deserialize<SimpleClassWithKeyValuePairs>(result);
-            Assert.Equal("key", value.KvpWStrVal.Key);
-            Assert.Equal("key", value.KvpWObjVal.Key);
-            Assert.Equal("key", value.KvpWClassVal.Key);
-            Assert.Equal("key", value.KvpWStrKvpVal.Key);
-            Assert.Equal("key", value.KvpWObjKvpVal.Key);
-            Assert.Equal("key", value.KvpWClassKvpVal.Key);
-            Assert.Equal("key", value.KvpWStrKvpVal.Value.Key);
-            Assert.Equal("key", value.KvpWObjKvpVal.Value.Key);
-            Assert.Equal("key", value.KvpWClassKvpVal.Value.Key);
-
-            Assert.Null(value.KvpWStrVal.Value);
-            Assert.Null(value.KvpWObjVal.Value);
-            Assert.Null(value.KvpWClassVal.Value);
-            Assert.Null(value.KvpWStrKvpVal.Value.Value);
-            Assert.Null(value.KvpWObjKvpVal.Value.Value);
-            Assert.Null(value.KvpWClassKvpVal.Value.Value);
-        }
-
-        [Fact]
         public static void WriteGenericCollectionWrappers()
         {
             SimpleTestClassWithGenericCollectionWrappers obj1 = new SimpleTestClassWithGenericCollectionWrappers();

diff --git a/src/libraries/System.Text.Json/tests/Serialization/CollectionTests/CollectionTests.KeyValuePair.cs b/src/libraries/System.Text.Json/tests/Serialization/CollectionTests/CollectionTests.KeyValuePair.cs
new file mode 100644 (file)
index 0000000..9e295d5
--- /dev/null
+++ b/src/libraries/System.Text.Json/tests/Serialization/CollectionTests/CollectionTests.KeyValuePair.cs
@@ -0,0 +1,283 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Collections.Generic;
+using Xunit;
+
+namespace System.Text.Json.Serialization.Tests
+{
+    public static partial class CollectionTests
+    {
+        [Fact]
+        public static void ReadSimpleKeyValuePairFail()
+        {
+            // Invalid form: no Value
+            Assert.Throws<JsonException>(() => JsonSerializer.Deserialize<KeyValuePair<string, int>>(@"{""Key"": 123}"));
+
+            // Invalid form: extra property
+            Assert.Throws<JsonException>(() => JsonSerializer.Deserialize<KeyValuePair<string, int>>(@"{""Key"": ""Key"", ""Value"": 123, ""Value2"": 456}"));
+
+            // Invalid form: does not contain both Key and Value properties
+            Assert.Throws<JsonException>(() => JsonSerializer.Deserialize<KeyValuePair<string, int>>(@"{""Key"": ""Key"", ""Val"": 123"));
+        }
+
+        [Fact]
+        public static void ReadListOfKeyValuePair()
+        {
+            List<KeyValuePair<string, int>> input = JsonSerializer.Deserialize<List<KeyValuePair<string, int>>>(@"[{""Key"": ""123"", ""Value"": 123},{""Key"": ""456"", ""Value"": 456}]");
+
+            Assert.Equal(2, input.Count);
+            Assert.Equal("123", input[0].Key);
+            Assert.Equal(123, input[0].Value);
+            Assert.Equal("456", input[1].Key);
+            Assert.Equal(456, input[1].Value);
+        }
+
+        [Fact]
+        public static void ReadKeyValuePairOfList()
+        {
+            KeyValuePair<string, List<int>> input = JsonSerializer.Deserialize<KeyValuePair<string, List<int>>>(@"{""Key"":""Key"", ""Value"":[1, 2, 3]}");
+
+            Assert.Equal("Key", input.Key);
+            Assert.Equal(3, input.Value.Count);
+            Assert.Equal(1, input.Value[0]);
+            Assert.Equal(2, input.Value[1]);
+            Assert.Equal(3, input.Value[2]);
+        }
+
+        [Theory]
+        [InlineData(@"{""Key"":""Key"", ""Value"":{""Key"":1, ""Value"":2}}")]
+        [InlineData(@"{""Key"":""Key"", ""Value"":{""Value"":2, ""Key"":1}}")]
+        [InlineData(@"{""Value"":{""Key"":1, ""Value"":2}, ""Key"":""Key""}")]
+        [InlineData(@"{""Value"":{""Value"":2, ""Key"":1}, ""Key"":""Key""}")]
+        public static void ReadKeyValuePairOfKeyValuePair(string json)
+        {
+            KeyValuePair<string, KeyValuePair<int, int>> input = JsonSerializer.Deserialize<KeyValuePair<string, KeyValuePair<int, int>>>(json);
+
+            Assert.Equal("Key", input.Key);
+            Assert.Equal(1, input.Value.Key);
+            Assert.Equal(2, input.Value.Value);
+        }
+
+        [Fact]
+        public static void ReadKeyValuePairWithNullValues()
+        {
+            {
+                KeyValuePair<string, string> kvp = JsonSerializer.Deserialize<KeyValuePair<string, string>>(@"{""Key"":""key"",""Value"":null}");
+                Assert.Equal("key", kvp.Key);
+                Assert.Null(kvp.Value);
+            }
+
+            {
+                KeyValuePair<string, object> kvp = JsonSerializer.Deserialize<KeyValuePair<string, object>>(@"{""Key"":""key"",""Value"":null}");
+                Assert.Equal("key", kvp.Key);
+                Assert.Null(kvp.Value);
+            }
+
+            {
+                KeyValuePair<string, SimpleClassWithKeyValuePairs> kvp = JsonSerializer.Deserialize<KeyValuePair<string, SimpleClassWithKeyValuePairs>>(@"{""Key"":""key"",""Value"":null}");
+                Assert.Equal("key", kvp.Key);
+                Assert.Null(kvp.Value);
+            }
+
+            {
+                KeyValuePair<string, KeyValuePair<string, string>> kvp = JsonSerializer.Deserialize<KeyValuePair<string, KeyValuePair<string, string>>>(@"{""Key"":""key"",""Value"":{""Key"":""key"",""Value"":null}}");
+                Assert.Equal("key", kvp.Key);
+                Assert.Equal("key", kvp.Value.Key);
+                Assert.Null(kvp.Value.Value);
+            }
+
+            {
+                KeyValuePair<string, KeyValuePair<string, object>> kvp = JsonSerializer.Deserialize<KeyValuePair<string, KeyValuePair<string, object>>>(@"{""Key"":""key"",""Value"":{""Key"":""key"",""Value"":null}}");
+                Assert.Equal("key", kvp.Key);
+                Assert.Equal("key", kvp.Value.Key);
+                Assert.Null(kvp.Value.Value);
+            }
+
+            {
+                KeyValuePair<string, KeyValuePair<string, SimpleClassWithKeyValuePairs>> kvp = JsonSerializer.Deserialize<KeyValuePair<string, KeyValuePair<string, SimpleClassWithKeyValuePairs>>>(@"{""Key"":""key"",""Value"":{""Key"":""key"",""Value"":null}}");
+                Assert.Equal("key", kvp.Key);
+                Assert.Equal("key", kvp.Value.Key);
+                Assert.Null(kvp.Value.Value);
+            }
+        }
+
+        [Fact]
+        public static void ReadClassWithNullKeyValuePairValues()
+        {
+            string json =
+                    @"{" +
+                        @"""KvpWStrVal"":{" +
+                            @"""Key"":""key""," +
+                            @"""Value"":null" +
+                        @"}," +
+                        @"""KvpWObjVal"":{" +
+                            @"""Key"":""key""," +
+                            @"""Value"":null" +
+                        @"}," +
+                        @"""KvpWClassVal"":{" +
+                            @"""Key"":""key""," +
+                            @"""Value"":null" +
+                        @"}," +
+                        @"""KvpWStrKvpVal"":{" +
+                            @"""Key"":""key""," +
+                            @"""Value"":{" +
+                                @"""Key"":""key""," +
+                                @"""Value"":null" +
+                            @"}" +
+                        @"}," +
+                        @"""KvpWObjKvpVal"":{" +
+                            @"""Key"":""key""," +
+                            @"""Value"":{" +
+                                @"""Key"":""key""," +
+                                @"""Value"":null" +
+                            @"}" +
+                        @"}," +
+                        @"""KvpWClassKvpVal"":{" +
+                            @"""Key"":""key""," +
+                            @"""Value"":{" +
+                                @"""Key"":""key""," +
+                                @"""Value"":null" +
+                            @"}" +
+                        @"}" +
+                    @"}";
+            SimpleClassWithKeyValuePairs obj = JsonSerializer.Deserialize<SimpleClassWithKeyValuePairs>(json);
+
+            Assert.Equal("key", obj.KvpWStrVal.Key);
+            Assert.Equal("key", obj.KvpWObjVal.Key);
+            Assert.Equal("key", obj.KvpWClassVal.Key);
+            Assert.Equal("key", obj.KvpWStrKvpVal.Key);
+            Assert.Equal("key", obj.KvpWObjKvpVal.Key);
+            Assert.Equal("key", obj.KvpWClassKvpVal.Key);
+            Assert.Equal("key", obj.KvpWStrKvpVal.Value.Key);
+            Assert.Equal("key", obj.KvpWObjKvpVal.Value.Key);
+            Assert.Equal("key", obj.KvpWClassKvpVal.Value.Key);
+
+            Assert.Null(obj.KvpWStrVal.Value);
+            Assert.Null(obj.KvpWObjVal.Value);
+            Assert.Null(obj.KvpWClassVal.Value);
+            Assert.Null(obj.KvpWStrKvpVal.Value.Value);
+            Assert.Null(obj.KvpWObjKvpVal.Value.Value);
+            Assert.Null(obj.KvpWClassKvpVal.Value.Value);
+        }
+
+        [Fact]
+        public static void Kvp_NullKeyIsFine()
+        {
+            KeyValuePair<string, string> kvp = JsonSerializer.Deserialize<KeyValuePair<string, string>>(@"{""Key"":null,""Value"":null}");
+            Assert.Null(kvp.Key);
+            Assert.Null(kvp.Value);
+        }
+
+        [Fact]
+        public static void WritePrimitiveKeyValuePair()
+        {
+            KeyValuePair<string, int> input = new KeyValuePair<string, int>("Key", 123);
+
+            string json = JsonSerializer.Serialize(input);
+            Assert.Equal(@"{""Key"":""Key"",""Value"":123}", json);
+        }
+
+        [Fact]
+        public static void WriteListOfKeyValuePair()
+        {
+            List<KeyValuePair<string, int>> input = new List<KeyValuePair<string, int>>
+            {
+                new KeyValuePair<string, int>("123", 123),
+                new KeyValuePair<string, int>("456", 456)
+            };
+
+            string json = JsonSerializer.Serialize(input);
+            Assert.Equal(@"[{""Key"":""123"",""Value"":123},{""Key"":""456"",""Value"":456}]", json);
+        }
+
+        [Fact]
+        public static void WriteKeyValuePairOfList()
+        {
+            KeyValuePair<string, List<int>> input = new KeyValuePair<string, List<int>>("Key", new List<int> { 1, 2, 3 });
+
+            string json = JsonSerializer.Serialize(input);
+            Assert.Equal(@"{""Key"":""Key"",""Value"":[1,2,3]}", json);
+        }
+
+        [Fact]
+        public static void WriteKeyValuePairOfKeyValuePair()
+        {
+            KeyValuePair<string, KeyValuePair<string, int>> input = new KeyValuePair<string, KeyValuePair<string, int>>(
+                "Key", new KeyValuePair<string, int>("Key", 1));
+
+            string json = JsonSerializer.Serialize(input);
+            Assert.Equal(@"{""Key"":""Key"",""Value"":{""Key"":""Key"",""Value"":1}}", json);
+        }
+
+        [Fact]
+        public static void WriteKeyValuePairWithNullValues()
+        {
+            {
+                KeyValuePair<string, string> kvp = new KeyValuePair<string, string>("key", null);
+                Assert.Equal(@"{""Key"":""key"",""Value"":null}", JsonSerializer.Serialize(kvp));
+            }
+
+            {
+                KeyValuePair<string, object> kvp = new KeyValuePair<string, object>("key", null);
+                Assert.Equal(@"{""Key"":""key"",""Value"":null}", JsonSerializer.Serialize(kvp));
+            }
+
+            {
+                KeyValuePair<string, SimpleClassWithKeyValuePairs> kvp = new KeyValuePair<string, SimpleClassWithKeyValuePairs>("key", null);
+                Assert.Equal(@"{""Key"":""key"",""Value"":null}", JsonSerializer.Serialize(kvp));
+            }
+
+            {
+                KeyValuePair<string, KeyValuePair<string, string>> kvp = new KeyValuePair<string, KeyValuePair<string, string>>("key", new KeyValuePair<string, string>("key", null));
+                Assert.Equal(@"{""Key"":""key"",""Value"":{""Key"":""key"",""Value"":null}}", JsonSerializer.Serialize(kvp));
+            }
+
+            {
+                KeyValuePair<string, KeyValuePair<string, object>> kvp = new KeyValuePair<string, KeyValuePair<string, object>>("key", new KeyValuePair<string, object>("key", null));
+                Assert.Equal(@"{""Key"":""key"",""Value"":{""Key"":""key"",""Value"":null}}", JsonSerializer.Serialize(kvp));
+            }
+
+            {
+                KeyValuePair<string, KeyValuePair<string, SimpleClassWithKeyValuePairs>> kvp = new KeyValuePair<string, KeyValuePair<string, SimpleClassWithKeyValuePairs>>("key", new KeyValuePair<string, SimpleClassWithKeyValuePairs>("key", null));
+                Assert.Equal(@"{""Key"":""key"",""Value"":{""Key"":""key"",""Value"":null}}", JsonSerializer.Serialize(kvp));
+            }
+        }
+
+        [Fact]
+        public static void WriteClassWithNullKeyValuePairValues_NullWrittenAsEmptyObject()
+        {
+            var value = new SimpleClassWithKeyValuePairs()
+            {
+                KvpWStrVal = new KeyValuePair<string, string>("key", null),
+                KvpWObjVal = new KeyValuePair<string, object>("key", null),
+                KvpWClassVal = new KeyValuePair<string, SimpleClassWithKeyValuePairs>("key", null),
+                KvpWStrKvpVal = new KeyValuePair<string, KeyValuePair<string, string>>("key", new KeyValuePair<string, string>("key", null)),
+                KvpWObjKvpVal = new KeyValuePair<string, KeyValuePair<string, object>>("key", new KeyValuePair<string, object>("key", null)),
+                KvpWClassKvpVal = new KeyValuePair<string, KeyValuePair<string, SimpleClassWithKeyValuePairs>>("key", new KeyValuePair<string, SimpleClassWithKeyValuePairs>("key", null)),
+            };
+
+            string result = JsonSerializer.Serialize(value);
+
+            // Roundtrip to ensure serialize was correct.
+            value = JsonSerializer.Deserialize<SimpleClassWithKeyValuePairs>(result);
+            Assert.Equal("key", value.KvpWStrVal.Key);
+            Assert.Equal("key", value.KvpWObjVal.Key);
+            Assert.Equal("key", value.KvpWClassVal.Key);
+            Assert.Equal("key", value.KvpWStrKvpVal.Key);
+            Assert.Equal("key", value.KvpWObjKvpVal.Key);
+            Assert.Equal("key", value.KvpWClassKvpVal.Key);
+            Assert.Equal("key", value.KvpWStrKvpVal.Value.Key);
+            Assert.Equal("key", value.KvpWObjKvpVal.Value.Key);
+            Assert.Equal("key", value.KvpWClassKvpVal.Value.Key);
+
+            Assert.Null(value.KvpWStrVal.Value);
+            Assert.Null(value.KvpWObjVal.Value);
+            Assert.Null(value.KvpWClassVal.Value);
+            Assert.Null(value.KvpWStrKvpVal.Value.Value);
+            Assert.Null(value.KvpWObjKvpVal.Value.Value);
+            Assert.Null(value.KvpWClassKvpVal.Value.Value);
+        }
+    }
+}

diff --git a/src/libraries/System.Text.Json/tests/System.Text.Json.Tests.csproj b/src/libraries/System.Text.Json/tests/System.Text.Json.Tests.csproj
index c55cc68..2693078 100644 (file)
--- a/src/libraries/System.Text.Json/tests/System.Text.Json.Tests.csproj
+++ b/src/libraries/System.Text.Json/tests/System.Text.Json.Tests.csproj
@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <TargetFrameworks>$(NetCoreAppCurrent);$(NetFrameworkCurrent)</TargetFrameworks>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
@@ -8,8 +8,7 @@
     <DefineConstants Condition="'$(TargetFramework)' == '$(NetCoreAppCurrent)'">$(DefineConstants);BUILDING_INBOX_LIBRARY</DefineConstants> 
   </PropertyGroup>
   <ItemGroup>
-    <Compile Include="$(CommonTestPath)System\IO\WrappedMemoryStream.cs"
-             Link="CommonTest\System\IO\WrappedMemoryStream.cs" />
+    <Compile Include="$(CommonTestPath)System\IO\WrappedMemoryStream.cs" Link="CommonTest\System\IO\WrappedMemoryStream.cs" />
     <Compile Include="BitStackTests.cs" />
     <Compile Include="BufferFactory.cs" />
     <Compile Include="BufferSegment.cs" />
@@ -45,6 +44,7 @@
     <Compile Include="Serialization\CollectionTests\CollectionTests.Generic.Read.cs" />
     <Compile Include="Serialization\CollectionTests\CollectionTests.Generic.Write.cs" />
     <Compile Include="Serialization\CollectionTests\CollectionTests.Immutable.Read.cs" />
+    <Compile Include="Serialization\CollectionTests\CollectionTests.KeyValuePair.cs" />
     <Compile Include="Serialization\CollectionTests\CollectionTests.NonGeneric.Read.cs" />
     <Compile Include="Serialization\CollectionTests\CollectionTests.NonGeneric.Write.cs" />
     <Compile Include="Serialization\CollectionTests\CollectionTests.ObjectModel.Read.cs" />
@@ -137,12 +137,10 @@
     <Compile Include="Utf8JsonWriterTests.cs" />
   </ItemGroup>
   <ItemGroup>
-    <Compile Include="..\src\System\Text\Json\BitStack.cs"
-             Link="BitStack.cs" />
+    <Compile Include="..\src\System\Text\Json\BitStack.cs" Link="BitStack.cs" />
   </ItemGroup>
   <ItemGroup Condition="'$(TargetFramework)' == '$(NetFrameworkCurrent)'">
-    <Compile Include="$(CommonPath)System\Buffers\ArrayBufferWriter.cs"
-             Link="CommonTest\System\Buffers\ArrayBufferWriter.cs" />
+    <Compile Include="$(CommonPath)System\Buffers\ArrayBufferWriter.cs" Link="CommonTest\System\Buffers\ArrayBufferWriter.cs" />
   </ItemGroup>
   <ItemGroup>
     <PackageReference Include="Newtonsoft.Json" Version="$(NewtonsoftJsonVersion)" />