system.text.json: update oauth

Update OAuth-related code to use System.Text.Json rather than
Json.NET for JSON serialization.

Author: ldennington

src/shared/Core/Authentication/OAuth/Json/DeviceAuthorizationEndpointResponseJson.cs

@@ -1,23 +1,26 @@
 using System;
-using Newtonsoft.Json;
+using System.Text.Json.Serialization;
 
 namespace GitCredentialManager.Authentication.OAuth.Json
 {
     public class DeviceAuthorizationEndpointResponseJson
     {
-        [JsonProperty("device_code", Required = Required.Always)]
+        [JsonRequired]
+        [JsonPropertyName("device_code")]
         public string DeviceCode { get; set; }
 
-        [JsonProperty("user_code", Required = Required.Always)]
+        [JsonRequired]
+        [JsonPropertyName("user_code")]
         public string UserCode { get; set; }
 
-        [JsonProperty("verification_uri", Required = Required.Always)]
+        [JsonRequired]
+        [JsonPropertyName("verification_uri")]
         public Uri VerificationUri { get; set; }
 
-        [JsonProperty("expires_in")]
+        [JsonPropertyName("expires_in")]
         public long ExpiresIn { get; set; }
 
-        [JsonProperty("interval")]
+        [JsonPropertyName("interval")]
         public long PollingInterval { get; set; }
 
         public OAuth2DeviceCodeResult ToResult()

src/shared/Core/Authentication/OAuth/Json/ErrorResponseJson.cs

@@ -1,18 +1,20 @@
 using System;
 using System.Text;
-using Newtonsoft.Json;
+using System.Text.Json;
+using System.Text.Json.Serialization;
 
 namespace GitCredentialManager.Authentication.OAuth.Json
 {
     public class ErrorResponseJson
     {
-        [JsonProperty("error", Required = Required.Always)]
+        [JsonRequired]
+        [JsonPropertyName("error")]
         public string Error { get; set; }
 
-        [JsonProperty("error_description")]
+        [JsonPropertyName("error_description")]
         public string Description { get; set; }
 
-        [JsonProperty("error_uri")]
+        [JsonPropertyName("error_uri")]
         public Uri Uri { get; set; }
 
         public OAuth2Exception ToException(Exception innerException = null)

src/shared/Core/Authentication/OAuth/OAuth2Client.cs

@@ -5,7 +5,7 @@
 using System.Threading;
 using System.Threading.Tasks;
 using GitCredentialManager.Authentication.OAuth.Json;
-using Newtonsoft.Json;
+using System.Text.Json;
 
 namespace GitCredentialManager.Authentication.OAuth
 {
@@ -318,7 +318,10 @@ public async Task<OAuth2TokenResult> GetTokenByDeviceCodeAsync(OAuth2DeviceCodeR
                             return result;
                         }
 
-                        var error = JsonConvert.DeserializeObject<ErrorResponseJson>(json);
+                        var error = JsonSerializer.Deserialize<ErrorResponseJson>(json, new JsonSerializerOptions
+                        {
+                            PropertyNameCaseInsensitive = true
+                        });
 
                         switch (error.Error)
                         {
@@ -408,7 +411,7 @@ protected static bool TryDeserializeJson<T>(string json, out T obj)
         {
             try
             {
-                obj = JsonConvert.DeserializeObject<T>(json);
+                obj = JsonSerializer.Deserialize<T>(json);
                 return true;
             }
             catch

src/shared/TestInfrastructure/Objects/TestOAuth2Server.cs

@@ -8,7 +8,7 @@
 using System.Threading.Tasks;
 using GitCredentialManager.Authentication.OAuth;
 using GitCredentialManager.Authentication.OAuth.Json;
-using Newtonsoft.Json;
+using System.Text.Json;
 using Xunit;
 
 namespace GitCredentialManager.Tests.Objects
@@ -159,7 +159,7 @@ private async Task<HttpResponseMessage> OnDeviceAuthorizationEndpointAsync(HttpR
                 VerificationUri = _deviceCodeVerificationUri,
             };
 
-            string responseJson = JsonConvert.SerializeObject(deviceResp);
+            string responseJson = JsonSerializer.Serialize(deviceResp);
 
             return new HttpResponseMessage(HttpStatusCode.OK)
             {
@@ -234,7 +234,7 @@ private async Task<HttpResponseMessage> OnTokenEndpointAsync(HttpRequestMessage
                         Error = OAuth2Constants.DeviceAuthorization.Errors.AuthorizationPending
                     };
 
-                    var errorJson = JsonConvert.SerializeObject(errorResp);
+                    var errorJson = JsonSerializer.Serialize(errorResp);
 
                     return new HttpResponseMessage(HttpStatusCode.BadRequest)
                     {
@@ -248,7 +248,7 @@ private async Task<HttpResponseMessage> OnTokenEndpointAsync(HttpRequestMessage
                 throw new Exception($"Unknown grant type '{grantType}'");
             }
 
-            string responseJson = JsonConvert.SerializeObject(tokenResp);
+            string responseJson = JsonSerializer.Serialize(tokenResp);
 
             return new HttpResponseMessage(HttpStatusCode.OK)
             {