Migrate NSwag core to System.Text.Json (v15) - [WIP]#5355
Open
Migrate NSwag core to System.Text.Json (v15) - [WIP]#5355
Conversation
Phase 0: Add UseLocalNJsonSchemaProjects switch to Directory.Build.props and conditional NJsonSchema project/NuGet references to all 6 projects. Phase 1: Add 5 OpenAPI document serialization snapshot tests using Verify to lock down behavior before and after migration. Phase 2: Migrate all 28 NSwag.Core model files from Newtonsoft attributes to STJ equivalents ([JsonPropertyName], [JsonIgnore], [JsonPropertyOrder]). Rewrite OpenApiPathItemConverter for STJ. Add EnumMemberStringEnumConverter for [EnumMember]-aware enum serialization. Add OpenApiParameterJsonConverter to handle the required bool/array property collision between OpenApiParameter and JsonSchema. Add parameterless JsonConstructor to OpenApiComponents for STJ deserialization support. 58/63 NSwag.Core tests pass (4 remaining failures in reference resolution and external file loading - see docs/plans/findings.md).
- Remove [JsonRequired] from OpenApiOAuthFlow.Scopes (real-world specs have OAuth flows without scopes, Newtonsoft was more lenient) - Update findings.md to reflect 0 remaining failures - Remove temp debug test
- NSwagDocumentBase: Replace JObject/JToken with JsonNode/JsonObject, JsonConvert with JsonSerializer, JsonSerializerSettings with JsonSerializerOptions (CamelCase naming, JsonStringEnumConverter) - 10 command files: mechanical [JsonProperty] → [JsonPropertyName], [JsonIgnore] namespace swap, JsonConvert → JsonSerializer
- Core.Yaml: Replace ExpandoObjectConverter with recursive JsonNode to ExpandoObject conversion for YamlDotNet compatibility - AspNetCore: Replace JsonConvert with JsonSerializer in SwaggerUi settings and JsonExceptionFilterAttribute, rewrite exception serialization without Newtonsoft JsonExceptionConverter
- Remove NJsonSchema.NewtonsoftJson package/project reference - Replace unused Newtonsoft using with System.Text.Json.Serialization - Replace JsonConvert.SerializeObject with JsonSerializer.Serialize
- New NSwag.Generation.NewtonsoftJson project with UseNewtonsoftJson() extension method and NewtonsoftJsonSettingsResolver for ASP.NET Core MvcNewtonsoftJsonOptions detection - Remove Newtonsoft using from AspNetCoreOpenApiDocumentGenerator, deprecate GetJsonSerializerSettings in favor of new package - Remove last Newtonsoft usings from CodeGeneration projects Only NSwag.AspNet.WebApi (legacy) and NSwagStudio (WPF) retain Newtonsoft dependencies. All other NSwag projects are now STJ-only.
…ttings - Enable UseLocalNJsonSchemaProjects=true in Directory.Build.props for development on this branch - Replace NewtonsoftJsonSchemaGeneratorSettings with SystemTextJsonSchemaGeneratorSettings across 26 test files - Update snapshot files to reflect STJ-based schema generation output - Remove orphaned Newtonsoft-only test class and its snapshots - Add JsonElement safety net in CSharpValueGenerator for large specs
RicoSuter
changed the title
…nsoft removal - Fix null reference in NSwagDocumentBase (lines 181, 518) - Cache JsonSerializerOptions as static readonly in NSwagDocumentBase - Add depth limit and try-catch to JsonExceptionFilterAttribute serialization - Remove hard Newtonsoft dependency from NSwagServiceCollectionExtensions (reflection-based) - Fix YAML boolean/number type loss (WithAttemptingUnquotedStringTypeDeserialization) - Migrate YamlDocumentTests from Newtonsoft.Json.Linq to System.Text.Json.Nodes - Add parameter IsRequired round-trip test and YAML round-trip test - Add missing NSwag.Generation.NewtonsoftJson reference to AspNetCore.Tests - Fix QueryParametersTests JToken assertion for STJ - Bump Namotion.Reflection to 3.5.0 - Add review.md and migration.md, remove findings.md
3 tasks
RicoSuter
added a commit
that referenced
this pull request
Apr 21, 2026
Pulled from PR #5355 so the v15 integration branch can build against local NJsonSchema v12 source immediately, validating the sibling-checkout CI setup end-to-end rather than waiting for the STJ migration PR to land. - Directory.Build.props: new UseLocalNJsonSchemaProjects property, default true on v15 - 8 csprojs get a pair of conditional ItemGroup blocks (ProjectReference when UseLocalNJsonSchemaProjects=true, PackageReference otherwise): NSwag.Core, NSwag.Core.Yaml, NSwag.CodeGeneration, NSwag.CodeGeneration.CSharp, NSwag.CodeGeneration.TypeScript, NSwag.Generation, NSwag.AspNet.WebApi, NSwag.CodeGeneration.Tests Verified locally: NSwag.Core, NSwag.CodeGeneration.CSharp, and NSwag.Generation all build clean with ProjectReference resolving to ../NJsonSchema/src/... Pre-release cleanup updated in plan_v15.md and this change noted in changelog_v15.md.
RicoSuter
added a commit
that referenced
this pull request
Apr 21, 2026
* Set up v15 integration branch: plan doc, changelog, CI triggers, sibling NJsonSchema checkout - Add docs/plan_v15.md describing the v15 scope, dependency on NJsonSchema v12, development workflow (UseLocalNJsonSchemaProjects=true), branch model, release plan, CI setup, and pre-release cleanup checklist - Add docs/changelog_v15.md as the running landed-changes log and v14 → v15 migration guide (starts empty with structural placeholders for planned PR #5355 and NJsonSchema v12 cascaded changes) - Add v15 to OnPullRequestBranches / OnPushBranches in build/Build.CI.GitHubActions.cs and the regenerated workflow YAMLs - Hand-edit both workflow YAMLs to clone RicoSuter/NJsonSchema@v12 as a sibling directory before build, so project references in UseLocalNJsonSchemaProjects=true mode resolve on CI (the clone step will be reverted when NUKE regenerates the YAMLs at v15 → master merge time; see cleanup checklist in plan_v15.md) * Add UseLocalNJsonSchemaProjects mechanism for v15 dev Pulled from PR #5355 so the v15 integration branch can build against local NJsonSchema v12 source immediately, validating the sibling-checkout CI setup end-to-end rather than waiting for the STJ migration PR to land. - Directory.Build.props: new UseLocalNJsonSchemaProjects property, default true on v15 - 8 csprojs get a pair of conditional ItemGroup blocks (ProjectReference when UseLocalNJsonSchemaProjects=true, PackageReference otherwise): NSwag.Core, NSwag.Core.Yaml, NSwag.CodeGeneration, NSwag.CodeGeneration.CSharp, NSwag.CodeGeneration.TypeScript, NSwag.Generation, NSwag.AspNet.WebApi, NSwag.CodeGeneration.Tests Verified locally: NSwag.Core, NSwag.CodeGeneration.CSharp, and NSwag.Generation all build clean with ProjectReference resolving to ../NJsonSchema/src/... Pre-release cleanup updated in plan_v15.md and this change noted in changelog_v15.md. * Add CLAUDE.md guide for contributor and Claude sessions - Project Overview: what NSwag is, its distribution channels, NJsonSchema dep - Cross-check with NJsonSchema: direction of change, when NSwag work needs NJsonSchema awareness (extension/overrides, API limitations, spec keyword parity, dependency bumping during v15) - Supported spec targets: Swagger 2.0 / OpenAPI 3.0.x / OpenAPI 3.1, with a note that master is 3.0-oriented and v15 completes 3.1 support - Build and test, high-level architecture by project layer, v15 branch conventions, repo-wide settings (TreatWarningsAsErrors, strong-naming, artifacts output, ImplicitUsings/LangVersion) - Code style conventions (analyzer policy, no abbreviations, CRLF, AAA tests) - Git rule: no AI attribution in commits / PRs / comments * Pre-build NJsonSchema in Release before NSwag CI build CI was failing with MSB3030 during NSwag.ConsoleCore publish: "Could not copy the file .../NJsonSchema/artifacts/bin/.../release_net8.0/ NJsonSchema.dll because it was not found." Root cause: with UseArtifactsOutput=true on both repos, MSBuild's Configuration=Release property does not reliably propagate across the repo boundary when NSwag builds NJsonSchema project references transitively. NJsonSchema ends up compiled to artifacts/bin/*/debug_* while NSwag expects release_* for the --no-build publish step, so publish fails. Fix: add an explicit pre-build step after the sibling NJsonSchema clone that runs 'dotnet build NJsonSchema.sln -c Release' in ../NJsonSchema. The Release artifacts are then present when NSwag's build invokes dotnet publish --no-build. Doc updated in plan_v15.md with the rationale. * Update CLAUDE.md with v15 project documentation and conventions
…o-stj # Conflicts: # Directory.Build.props # src/NSwag.CodeGeneration.CSharp.Tests/Snapshots/UseRequiredKeywordNewtonsoftJsonSchemaGeneratorTests.When_setting_is_disabled_properties_with_required_attribute_should_generate_with_required_keyword.verified.txt # src/NSwag.CodeGeneration.CSharp.Tests/Snapshots/UseRequiredKeywordNewtonsoftJsonSchemaGeneratorTests.When_setting_is_disabled_properties_with_required_keyword_and_attribute_should_generate_with_required_keyword.verified.txt # src/NSwag.CodeGeneration.CSharp.Tests/Snapshots/UseRequiredKeywordNewtonsoftJsonSchemaGeneratorTests.When_setting_is_disabled_properties_with_required_keyword_should_generate_with_required_keyword.verified.txt # src/NSwag.CodeGeneration.CSharp.Tests/Snapshots/UseRequiredKeywordNewtonsoftJsonSchemaGeneratorTests.When_setting_is_enabled_properties_with_required_attribute_should_generate_with_required_keyword.verified.txt # src/NSwag.CodeGeneration.CSharp.Tests/Snapshots/UseRequiredKeywordNewtonsoftJsonSchemaGeneratorTests.When_setting_is_enabled_properties_with_required_keyword_and_attribute_should_generate_with_required_keyword.verified.txt # src/NSwag.CodeGeneration.CSharp.Tests/Snapshots/UseRequiredKeywordSystemTextJsonSchemaGeneratorSettingsTests.When_setting_is_disabled_properties_with_required_attribute_should_generate_with_required_keyword.verified.txt # src/NSwag.CodeGeneration.CSharp.Tests/Snapshots/UseRequiredKeywordSystemTextJsonSchemaGeneratorSettingsTests.When_setting_is_disabled_properties_with_required_keyword_and_attribute_should_generate_with_required_keyword.verified.txt # src/NSwag.CodeGeneration.CSharp.Tests/Snapshots/UseRequiredKeywordSystemTextJsonSchemaGeneratorSettingsTests.When_setting_is_disabled_properties_with_required_keyword_should_generate_with_required_keyword.verified.txt # src/NSwag.CodeGeneration.CSharp.Tests/Snapshots/UseRequiredKeywordSystemTextJsonSchemaGeneratorSettingsTests.When_setting_is_enabled_properties_with_required_attribute_should_generate_with_required_keyword.verified.txt # src/NSwag.CodeGeneration.CSharp.Tests/Snapshots/UseRequiredKeywordSystemTextJsonSchemaGeneratorSettingsTests.When_setting_is_enabled_properties_with_required_keyword_and_attribute_should_generate_with_required_keyword.verified.txt # src/NSwag.CodeGeneration.CSharp/NSwag.CodeGeneration.CSharp.csproj # src/NSwag.CodeGeneration.TypeScript/NSwag.CodeGeneration.TypeScript.csproj # src/NSwag.CodeGeneration/NSwag.CodeGeneration.csproj # src/NSwag.Core.Yaml/NSwag.Core.Yaml.csproj # src/NSwag.Core/NSwag.Core.csproj # src/NSwag.Generation/NSwag.Generation.csproj
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
No description provided.