feat!: close the #83 Newtonsoft migration tree — STJ-6 + STJ-2 tail (#119, #115)

CHANGELOG.md

@@ -8,6 +8,13 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ### Breaking changes
 
+- **Last-mile Newtonsoft removal — closes the #83 migration tree** (#119 STJ-6, #115 STJ-2 tail). Every Fallout source file is STJ-native; `Newtonsoft.Json.dll` survives in the closure only as a transitive of `NuGet.Packaging` and `Serilog.Formatting.Compact.Reader`. The `Newtonsoft.Json` `PackageVersion` is gone from `Directory.Packages.props` entirely.
+  - **`GitHubActions.GitHubEvent` is now `JsonObject`** (was Newtonsoft `JObject`). Consumers that introspect the event payload need to swap `using Newtonsoft.Json.Linq` → `using System.Text.Json.Nodes` and update accessors (`["key"].Value<T>()` → `["key"].GetValue<T>()`, `Property(name)` → indexer, etc.).
+  - **`Fallout.Utilities.Net` `HttpRequestExtensions.WithJsonContent` / `HttpResponseExtensions.GetBodyAsJson` defaults are STJ.** The `[Obsolete]`-marked Newtonsoft overloads (`JsonSerializerSettings` parameter, `JObject` return) are gone. `JsonSerializerOptions` overloads remain for explicit configuration; the parameterless default uses STJ with default options. `GetBodyAsJsonObject` returns `System.Text.Json.Nodes.JsonObject`.
+  - **`SlackMessageActionButton.Type` / `TeamsMessage.Type` / `TeamsMessage.Context`**: hand-written `[JsonProperty(...)]` attributes swapped to `[JsonPropertyName(...)]`. Consumer impact only if you subclass these types and added `[JsonProperty]`-style attributes — switch to `[JsonPropertyName]`.
+  - **`TwitterTasks`**: internal error-parsing path swapped from `JObject.Parse` to `JsonNode.Parse`. No public-API change.
+  - **`ArgumentsFromParametersFileAttribute`** (#115 STJ-2 tail): `parameters.json` reading swapped from `JObject` to `JsonObject`. Behaviour identical for valid input; STJ may be slightly stricter about malformed JSON.
+
 - **`SchemaUtility` rewritten on `System.Text.Json` — NJsonSchema gone** (#114, STJ-1 of #83). The build-parameter schema generator (which emits `.fallout/build.schema.json` for editor autocomplete) no longer goes through NJsonSchema. It now hand-rolls the draft-04 schema using `JsonNode`/`JsonObject` directly — same output shape, no Rico-entanglement.
   - **Dropped packages**: `NJsonSchema`, `NJsonSchema.NewtonsoftJson`, `NJsonSchema.Annotations`, `Namotion.Reflection` — four packages and ~12 transitive dependencies gone from `Fallout.Build`. `Newtonsoft.Json` stays in the closure only via `Fallout.Common`'s `*Tasks.cs` (Slack/Twitter/Teams) until #119 lands.
   - **API**: `SchemaUtility.GetJsonString(IFalloutBuild)` and `GetJsonDocument(IFalloutBuild)` unchanged for consumers.

Directory.Packages.props

@@ -15,7 +15,6 @@
     <PackageVersion Include="Microsoft.Extensions.DependencyModel" Version="10.0.0" />
     <PackageVersion Include="Nerdbank.GitVersioning" Version="3.7.115" />
     <PackageVersion Include="Microsoft.SourceLink.GitHub" Version="8.0.0" />
-    <PackageVersion Include="Newtonsoft.Json" Version="13.0.4" />
     <PackageVersion Include="NuGet.Packaging" Version="6.14.3" />
     <PackageVersion Include="Octokit" Version="14.0.0" />
     <PackageVersion Include="Serilog" Version="4.3.0" />

src/Fallout.Build/Execution/Extensions/ArgumentsFromParametersFileAttribute.cs

@@ -7,7 +7,8 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
-using Newtonsoft.Json.Linq;
+using System.Text.Json;
+using System.Text.Json.Nodes;
 using Fallout.Common.CI;
 using Fallout.Common.IO;
 using Fallout.Common.Utilities;
@@ -49,11 +50,11 @@ public void OnBuildCreated(IReadOnlyCollection<ExecutableTarget> executableTarge
         //         : value;
 
         var parameterMembers = ValueInjectionUtility.GetParameterMembers(Build.GetType(), includeUnlisted: true);
-        var jobjectsAndProfiles = new[] { (File: Constants.GetDefaultParametersFile(FalloutBuild.RootDirectory), Profile: Constants.DefaultProfileName) }
+        var parameterObjectsAndProfiles = new[] { (File: Constants.GetDefaultParametersFile(FalloutBuild.RootDirectory), Profile: Constants.DefaultProfileName) }
             .Where(x => File.Exists(x.File))
             .Concat(FalloutBuild.LoadedLocalProfiles.Select(x => (File: Constants.GetParametersProfileFile(FalloutBuild.RootDirectory, x), Profile: x)))
             .ForEachLazy(x => Assert.FileExists(x.File))
-            .Select(x => (JObject: JObject.Parse(File.ReadAllText(x.File)), x.Profile))
+            .Select(x => (JsonObject: JsonNode.Parse(File.ReadAllText(x.File)).NotNull().AsObject(), x.Profile))
             .Reverse();
 
         var passwords = new Dictionary<string, string>();
@@ -66,22 +67,22 @@ string DecryptValue(string profile, string name, string value)
 
         ParameterService.Instance.ArgumentsFromFilesService = (parameter, destinationType) =>
         {
-            var (property, profile) = jobjectsAndProfiles.Select(x => (Property: x.JObject.Property(parameter), x.Profile))
-                .Where(x => x.Property != null)
+            var (value, profile) = parameterObjectsAndProfiles.Select(x => (Value: x.JsonObject[parameter], x.Profile))
+                .Where(x => x.Value != null)
                 .FirstOrDefault();
-            if (property == null)
+            if (value == null)
                 return null;
 
             var member = parameterMembers.SingleOrDefault(x => ParameterService.GetParameterMemberName(x).EqualsOrdinalIgnoreCase(parameter));
             var scalarType = member?.GetMemberType().GetScalarType();
             if (typeof(IAbsolutePathHolder).IsAssignableFrom(scalarType))
-                return property.Value.ToObject<string>().Apply(x => !PathConstruction.HasPathRoot(x) ? FalloutBuild.RootDirectory / x : (AbsolutePath)x);
+                return value.GetValue<string>().Apply(x => !PathConstruction.HasPathRoot(x) ? FalloutBuild.RootDirectory / x : (AbsolutePath)x);
 
             if ((member?.HasCustomAttribute<SecretAttribute>() ?? false) &&
                 !BuildServerConfigurationGeneration.IsActive)
-                return DecryptValue(profile, parameter, property.Value.ToObject<string>());
+                return DecryptValue(profile, parameter, value.GetValue<string>());
 
-            return property.Value.ToObject(destinationType);
+            return value.Deserialize(destinationType);
         };
     }
 }

src/Fallout.Common/CI/GitHubActions/GitHubActions.cs

@@ -11,8 +11,7 @@
 using System.Net.Http;
 using System.Net.Http.Headers;
 using System.Text;
-using Newtonsoft.Json;
-using Newtonsoft.Json.Linq;
+using System.Text.Json.Nodes;
 using Fallout.Common.IO;
 using Fallout.Common.Tooling;
 using Fallout.Common.Utilities;
@@ -29,7 +28,7 @@ public partial class GitHubActions : Host, IBuildServer
 
     public new static GitHubActions Instance => Host.Instance as GitHubActions;
 
-    private readonly Lazy<JObject> _eventContext;
+    private readonly Lazy<JsonObject> _eventContext;
     private readonly Lazy<HttpClient> _httpClient;
     private readonly Lazy<long> _jobId;
 
@@ -38,7 +37,7 @@ internal GitHubActions()
         _eventContext = Lazy.Create(() =>
         {
             var content = File.ReadAllText(EventPath);
-            return JsonConvert.DeserializeObject<JObject>(content);
+            return JsonNode.Parse(content)?.AsObject() ?? new JsonObject();
         });
         _httpClient = Lazy.Create(() =>
         {
@@ -112,11 +111,10 @@ internal GitHubActions()
     public string Token => EnvironmentInfo.GetVariable("GITHUB_TOKEN");
     public long JobId => _jobId.Value;
 
-    public JObject GitHubEvent => _eventContext.Value;
+    public JsonObject GitHubEvent => _eventContext.Value;
     public bool IsPullRequest => EventName == "pull_request";
-    // Note: GitHubEvent stays JObject (Newtonsoft) public surface for v11; full JsonObject migration is a separate API-break PR.
-    public int? PullRequestNumber => GitHubEvent.Property("number")?.Value.Value<int>();
-    public string PullRequestAction => GitHubEvent.Property("action")?.Value.Value<string>();
+    public int? PullRequestNumber => GitHubEvent["number"]?.GetValue<int>();
+    public string PullRequestAction => GitHubEvent["action"]?.GetValue<string>();
 
     public AbsolutePath StepSummaryFile => EnvironmentInfo.GetVariable("GITHUB_STEP_SUMMARY");
 

src/Fallout.Common/Tools/Slack/SlackTasks.cs

@@ -8,8 +8,9 @@
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Net.Http;
+using System.Text.Json;
+using System.Text.Json.Serialization;
 using System.Threading.Tasks;
-using Newtonsoft.Json;
 using Fallout.Common.Tooling;
 using Fallout.Common.Utilities;
 using Fallout.Common.Utilities.Net;
@@ -28,7 +29,7 @@ public static void SendSlackMessage(Configure<SlackMessage> configurator, string
     public static async Task SendSlackMessageAsync(Configure<SlackMessage> configurator, string webhook)
     {
         var message = configurator(new SlackMessage());
-        var payload = JsonConvert.SerializeObject(message);
+        var payload = JsonSerializer.Serialize(message);
 
         var response = await s_client.CreateRequest(HttpMethod.Post, webhook)
             .WithFormUrlEncodedContent(new Dictionary<string, string> { ["payload"] = payload })
@@ -63,6 +64,6 @@ public static async Task<string> SendOrUpdateSlackMessage(Configure<SlackMessage
 [Serializable]
 public class SlackMessageActionButton : SlackMessageAction
 {
-    [JsonProperty("type")]
+    [JsonPropertyName("type")]
     public string Type => "button";
 }

src/Fallout.Common/Tools/Teams/Teams.Extensions.cs

@@ -1,17 +1,16 @@
-// Copyright 2026 Maintainers of Fallout.
+// Copyright 2026 Maintainers of Fallout.
 // Originally based on NUKE by Matthias Koch and contributors.
 // Distributed under the MIT License.
 // https://github.com/ChrisonSimtian/Fallout/blob/main/LICENSE
 
-using Newtonsoft.Json;
-using System;
+using System.Text.Json.Serialization;
 
 namespace Fallout.Common.Tools.Teams;
 
 public partial class TeamsMessage
 {
-    [JsonProperty("@type")]
+    [JsonPropertyName("@type")]
     internal string Type => "MessageCard";
-    [JsonProperty("@context")]
+    [JsonPropertyName("@context")]
     internal string Context => "http://schema.org/extensions";
 }

src/Fallout.Common/Tools/Twitter/TwitterTasks.cs

@@ -11,8 +11,8 @@
 using System.Net.Http;
 using System.Security.Cryptography;
 using System.Text;
+using System.Text.Json.Nodes;
 using System.Threading.Tasks;
-using Newtonsoft.Json.Linq;
 using Fallout.Common.Utilities;
 using Fallout.Common.Utilities.Collections;
 
@@ -95,8 +95,8 @@ private static string GetErrorFromBody(string response)
     {
         try
         {
-            var jResponse = JObject.Parse(response);
-            var message = (string) jResponse["errors"].NotNull()[0].NotNull()["message"];
+            var jResponse = JsonNode.Parse(response).NotNull().AsObject();
+            var message = jResponse["errors"].NotNull().AsArray()[0].NotNull()["message"]?.GetValue<string>();
             if (!string.IsNullOrEmpty(message))
                 return message;
         }

src/Fallout.Utilities.Net/Fallout.Utilities.Net.csproj

@@ -9,7 +9,6 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Newtonsoft.Json" />
     <PackageReference Include="System.Net.Http" />
     <PackageReference Include="System.Text.Json" />
   </ItemGroup>

src/Fallout.Utilities.Net/HttpRequest.Content.cs

@@ -6,42 +6,30 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
-using System.Linq;
 using System.Net.Http;
 using System.Net.Http.Headers;
 using System.Text;
 using System.Text.Json;
-using Newtonsoft.Json;
 
 namespace Fallout.Common.Utilities.Net;
 
 public static partial class HttpRequestExtensions
 {
     /// <summary>
-    /// Sets the JSON-serialized object as content via <see cref="Newtonsoft.Json.JsonConvert.SerializeObject(object?)"/>.
+    /// Sets the JSON-serialized object as content via <see cref="JsonSerializer.Serialize{TValue}(TValue, JsonSerializerOptions?)"/>.
     /// </summary>
     public static HttpRequestBuilder WithJsonContent<T>(this HttpRequestBuilder builder, T obj)
     {
-        var content = JsonConvert.SerializeObject(obj);
+        var content = JsonSerializer.Serialize(obj);
         return builder.WithStringContent(content, "application/json");
     }
 
     /// <summary>
-    /// Sets the JSON-serialized object as content via <see cref="Newtonsoft.Json.JsonConvert.SerializeObject(object?)"/>.
-    /// </summary>
-    [Obsolete("Use the JsonSerializerOptions overload instead. Newtonsoft.Json.JsonSerializerSettings is scheduled for removal in v11 as part of the System.Text.Json migration (#83).")]
-    public static HttpRequestBuilder WithJsonContent<T>(this HttpRequestBuilder builder, T obj, JsonSerializerSettings settings)
-    {
-        var content = JsonConvert.SerializeObject(obj, settings);
-        return builder.WithStringContent(content, "application/json");
-    }
-
-    /// <summary>
-    /// Sets the JSON-serialized object as content via <see cref="System.Text.Json.JsonSerializer.Serialize{TValue}(TValue, JsonSerializerOptions?)"/>.
+    /// Sets the JSON-serialized object as content via <see cref="JsonSerializer.Serialize{TValue}(TValue, JsonSerializerOptions?)"/>.
     /// </summary>
     public static HttpRequestBuilder WithJsonContent<T>(this HttpRequestBuilder builder, T obj, JsonSerializerOptions options)
     {
-        var content = System.Text.Json.JsonSerializer.Serialize(obj, options);
+        var content = JsonSerializer.Serialize(obj, options);
         return builder.WithStringContent(content, "application/json");
     }
 

src/Fallout.Utilities.Net/HttpResponse.Body.cs

@@ -3,75 +3,42 @@
 // Distributed under the MIT License.
 // https://github.com/ChrisonSimtian/Fallout/blob/main/LICENSE
 
-using System;
 using System.IO;
 using System.Text.Json;
 using System.Text.Json.Nodes;
 using System.Threading.Tasks;
-using Newtonsoft.Json;
-using Newtonsoft.Json.Linq;
 using Fallout.Common.IO;
 
 namespace Fallout.Common.Utilities.Net;
 
-// TODO: reduce with overloads
 public static partial class HttpResponseExtensions
 {
     /// <summary>
-    /// Reads the HTTP response body as JSON via <see cref="Newtonsoft.Json.JsonConvert.DeserializeObject{T}(string)"/>.
+    /// Reads the HTTP response body as JSON via <see cref="JsonSerializer.Deserialize{TValue}(string, JsonSerializerOptions?)"/>.
     /// </summary>
     public static async Task<T> GetBodyAsJson<T>(this HttpResponseInspector inspector)
     {
-        return JsonConvert.DeserializeObject<T>(await inspector.GetBodyAsync());
+        return JsonSerializer.Deserialize<T>(await inspector.GetBodyAsync());
     }
 
     /// <summary>
-    /// Reads the HTTP response body as a Newtonsoft <see cref="JObject"/>.
-    /// </summary>
-    [Obsolete("Use GetBodyAsJsonObject (returns System.Text.Json.Nodes.JsonObject) instead. Newtonsoft.Json.Linq.JObject is scheduled for removal in v11 as part of the System.Text.Json migration (#83).")]
-    public static async Task<JObject> GetBodyAsJson(this HttpResponseInspector inspector)
-    {
-        return await inspector.GetBodyAsJson<JObject>();
-    }
-
-    /// <summary>
-    /// Reads the HTTP response body as JSON via <see cref="Newtonsoft.Json.JsonConvert.DeserializeObject{T}(string, JsonSerializerSettings)"/>.
-    /// </summary>
-    [Obsolete("Use the JsonSerializerOptions overload instead. Newtonsoft.Json.JsonSerializerSettings is scheduled for removal in v11 as part of the System.Text.Json migration (#83).")]
-    public static async Task<T> GetBodyAsJson<T>(this HttpResponseInspector inspector, JsonSerializerSettings settings)
-    {
-        return JsonConvert.DeserializeObject<T>(await inspector.GetBodyAsync(), settings);
-    }
-
-    /// <summary>
-    /// Reads the HTTP response body as a Newtonsoft <see cref="JObject"/> using the given <paramref name="settings"/>.
-    /// </summary>
-    [Obsolete("Use GetBodyAsJsonObject with JsonSerializerOptions instead. Newtonsoft types are scheduled for removal in v11 as part of the System.Text.Json migration (#83).")]
-    public static async Task<JObject> GetBodyAsJson(this HttpResponseInspector inspector, JsonSerializerSettings settings)
-    {
-#pragma warning disable CS0618 // Self-call into the obsolete settings-taking generic overload; both retire together in v11.
-        return await inspector.GetBodyAsJson<JObject>(settings);
-#pragma warning restore CS0618
-    }
-
-    /// <summary>
-    /// Reads the HTTP response body as JSON via <see cref="System.Text.Json.JsonSerializer.Deserialize{TValue}(string, JsonSerializerOptions?)"/>.
+    /// Reads the HTTP response body as JSON via <see cref="JsonSerializer.Deserialize{TValue}(string, JsonSerializerOptions?)"/>.
     /// </summary>
     public static async Task<T> GetBodyAsJson<T>(this HttpResponseInspector inspector, JsonSerializerOptions options)
     {
-        return System.Text.Json.JsonSerializer.Deserialize<T>(await inspector.GetBodyAsync(), options);
+        return JsonSerializer.Deserialize<T>(await inspector.GetBodyAsync(), options);
     }
 
     /// <summary>
-    /// Reads the HTTP response body as a System.Text.Json <see cref="JsonObject"/>.
+    /// Reads the HTTP response body as a <see cref="JsonObject"/>.
     /// </summary>
     public static async Task<JsonObject> GetBodyAsJsonObject(this HttpResponseInspector inspector)
     {
         return JsonNode.Parse(await inspector.GetBodyAsync())?.AsObject();
     }
 
     /// <summary>
-    /// Reads the HTTP response body as a System.Text.Json <see cref="JsonObject"/> using the given <paramref name="options"/>.
+    /// Reads the HTTP response body as a <see cref="JsonObject"/> using the given <paramref name="options"/>.
     /// </summary>
     public static async Task<JsonObject> GetBodyAsJsonObject(this HttpResponseInspector inspector, JsonNodeOptions options)
     {