Describe System.Text.Json DOM types as free-form JSON in the OpenAPI document

docs/guide/clients.md

@@ -177,7 +177,7 @@ setting.
 
 With `--serializer message-pack-named` or `message-pack-keyed` and `--client refit`, the client
 project also holds two Liquid templates in `templates/`, `MessagePackContentSerializer.cs`, and a
-reference to the `MessagePack` package, 3.1.8. `.refitter` then names the folder in
+reference to the `MessagePack` package, 3.1.9. `.refitter` then names the folder in
 `customTemplateDirectory`. It also sets `generateDefaultAdditionalProperties` to `false`.
 
 The templates put these attributes on the generated models:

docs/guide/message-pack.md

@@ -113,7 +113,7 @@ Run this command in the solution directory:
 dotnet add src/Todos package Hardened.Requests.Serializers.MessagePack --version 0.0.0-HARDENED-VERSION
 ```
 
-The package depends on `MessagePack` 3.1.8, which brings MessagePack's source generator into the project.
+The package depends on `MessagePack` 3.1.9, which brings MessagePack's source generator into the project.
 
 The template's solution uses central package management. There, the command adds a `PackageReference` to `src/Todos/Todos.csproj` and a `PackageVersion` to `Directory.Packages.props`. The `PackageVersion` holds the version as a literal. The template's other Hardened packages use `$(HardenedVersion)`.
 

scripts/probes/JsonDomController.cs

@@ -0,0 +1,41 @@
+using System.Text.Json;
+using System.Text.Json.Nodes;
+using Hardened.Requests.Abstract.Attributes;
+using Hardened.Web.Runtime.Attributes;
+
+namespace Sample;
+
+/// <summary>
+/// Copied into a code-first Refit scaffold by scripts/verify-templates.sh, so the client Refitter
+/// generates from the document has to compile over the System.Text.Json DOM types. Their schemas
+/// once carried a property named this[], which Refitter refused.
+/// </summary>
+public record JsonDomEnvelope(
+    JsonElement Element,
+    JsonNode Node,
+    JsonObject Object,
+    JsonArray Array,
+    JsonValue Value,
+    JsonObject? MaybeObject
+);
+
+public class JsonDomController
+{
+    [Post("/dom/envelope")]
+    public JsonDomEnvelope Envelope(JsonDomEnvelope body) => body;
+
+    [Post("/dom/element")]
+    public JsonElement Element([FromBody] JsonElement body) => body;
+
+    [Post("/dom/node")]
+    public JsonNode Node([FromBody] JsonNode body) => body;
+
+    [Post("/dom/object")]
+    public JsonObject Object([FromBody] JsonObject body) => body;
+
+    [Post("/dom/array")]
+    public JsonArray Array([FromBody] JsonArray body) => body;
+
+    [Post("/dom/value")]
+    public JsonValue Value([FromBody] JsonValue body) => body;
+}

scripts/verify-templates.sh

@@ -676,6 +676,29 @@ for COMBO in "${COMBOS[@]}"; do
 
     run_tests "$OUT" GetTodo_ReadsTheMockedStore
 
+    # The System.Text.Json DOM types, on the rows where Refitter reads a document the server's
+    # code wrote. Their schemas once carried a property named this[], which Refitter refused, and
+    # the template's own handlers reach none of them. After the tests, because DocumentStatusTests
+    # fails on an operation it sends no request to, and removed again so the probes below serve
+    # the application as scaffolded. Not on the MessagePack rows, whose Liquid templates key every
+    # generated member and have no formatter for a free-form one.
+    if [ "$CONTRACT" = code ] && [ "$CLIENT" = refit ] && \
+       { [ "$SERIALIZER" = default ] || [ "$SERIALIZER" = json ]; }; then
+        cp "$REPO/scripts/probes/JsonDomController.cs" "$OUT/src/Sample/JsonDomController.cs"
+
+        if ! ( cd "$OUT" && dotnet build src/Sample.Client -v q --nologo ) > "$OUT/dom-probe.log" 2>&1; then
+            echo "   FAILED: the Refit client does not compile over the System.Text.Json DOM types - see $OUT/dom-probe.log"
+            FAILED=1
+        elif ! grep -rq '/dom/element"' "$OUT/src/Sample.Client/obj" --include='*.cs'; then
+            echo "   FAILED: the System.Text.Json DOM probe did not reach the Refit client"
+            FAILED=1
+        else
+            echo "   the Refit client compiles over the System.Text.Json DOM types"
+        fi
+
+        rm "$OUT/src/Sample/JsonDomController.cs"
+    fi
+
     # The client rows: the document the library's build wrote is what the client generated from,
     # and it is the file a consumer commits - so it has to exist, and it has to be the served
     # document. The opt-out row: no property, no file, no client project.

src/Directory.Packages.props

@@ -106,7 +106,7 @@
         <PackageVersion Include="Microsoft.Kiota.Http.HttpClientLibrary" Version="2.0.0" />
         <PackageVersion Include="Microsoft.OpenApi" Version="3.10.0" />
         <PackageVersion Include="Microsoft.OpenApi.YamlReader" Version="3.10.0" />
-        <PackageVersion Include="MessagePack" Version="3.1.8" />
+        <PackageVersion Include="MessagePack" Version="3.1.9" />
         <PackageVersion Include="Newtonsoft.Json" Version="13.0.3" />
         <PackageVersion Include="RazorBlade" Version="1.0.0" />
         <PackageVersion Include="Refit" Version="16.3.0" />

src/SourceGenerators/Hardened.SourceGenerator/OpenApiDocument/JsonSchemaWriter.cs

@@ -156,6 +156,16 @@ private static string SchemaFor(
             return BinaryPayload;
         }
 
+        // The System.Text.Json DOM holds whatever JSON arrived, so it is free-form on the wire.
+        // Reflected instead, JsonElement published its indexer as a property named this[] and
+        // JsonObject a required count, and Refitter refused the repeated this[] key.
+        var dom = JsonDom(type);
+
+        if (dom != null)
+        {
+            return dom;
+        }
+
         if (type is IArrayTypeSymbol array)
         {
             // byte[] is the payload itself, not a sequence of numbers. Every element type below
@@ -274,6 +284,36 @@ private static bool IsProblemType(INamedTypeSymbol owner, IPropertySymbol proper
         && property.Type.SpecialType == SpecialType.System_String
         && Requests.ProblemBodies.Implement(owner);
 
+    /// <summary>
+    /// The schema for a <c>System.Text.Json</c> DOM type, or null for anything else.
+    /// </summary>
+    /// <remarks>
+    /// Matched on the namespace as well as the name, so an application's own type named
+    /// <c>JsonNode</c> is still reflected.
+    /// </remarks>
+    private static string? JsonDom(ITypeSymbol type)
+    {
+        var space = type.ContainingNamespace?.ToDisplayString();
+
+        if (space == "System.Text.Json")
+        {
+            return type.Name == "JsonElement" ? "{}" : null;
+        }
+
+        if (space != "System.Text.Json.Nodes")
+        {
+            return null;
+        }
+
+        return type.Name switch
+        {
+            "JsonObject" => "{\"type\":\"object\"}",
+            "JsonArray" => "{\"type\":\"array\",\"items\":{}}",
+            "JsonNode" or "JsonValue" => "{}",
+            _ => null,
+        };
+    }
+
     /// <summary>
     /// Whether a type is a <c>System.IO.Stream</c>, base types walked.
     /// </summary>
@@ -515,6 +555,7 @@ private static string ObjectRef(
             if (
                 property.DeclaredAccessibility != Accessibility.Public
                 || property.IsStatic
+                || property.IsIndexer
                 || property.GetMethod == null
             )
             {

src/SourceGenerators/Hardened.Web.SourceGenerator.Tests/Hardened.Web.SourceGenerator.Tests.csproj

@@ -140,5 +140,13 @@
                  Link="Routing/RouteConstraintFactsTests.cs"/>
         <Compile Include="../Hardened.SourceGenerator.Tests/Web/RouteTemplateTests.cs"
                  Link="Routing/RouteTemplateTests.cs"/>
+
+        <!--
+            The document format module the export task writes a file through, so a test can take
+            the document this generator emits to YAML and to each HardenedOpenApiOutputVersion.
+            The generator does not compile it in, so this is the only copy in scope.
+        -->
+        <Compile Include="../Hardened.Generation.Shared/Document/*.cs"
+                 Link="Document/%(Filename)%(Extension)"/>
     </ItemGroup>
 </Project>