Initial import: Ais.Net.Models.Json (low-allocation polymorphic JSON)

[HowardvanRooijen]

Initial import of the low-allocation, UTF-8-first, polymorphic System.Text.Json serialization package for the Ais.Net.Models AIS message types — for broadcasting decoded messages over byte-oriented transports such as NATS and reconstructing the concrete .NET type on receipt.

Contents

• Ais.Net.Models.Json — source-generated (reflection-free) System.Text.Json; polymorphic round-trip via a $type discriminator; enums as numbers; nulls omitted. Public API: static AisMessageJson (SerializeToUtf8Bytes; serialize into an IBufferWriter<byte> or a reusable Utf8JsonWriter; deserialize from ReadOnlySpan<byte>; Options/TypeInfo) plus C# 14 extension members (message.ToJsonUtf8Bytes(), message.WriteJsonTo(writer), AisMessageBase.FromJsonUtf8(bytes)). The polymorphism is configured programmatically, so the core Ais.Net.Models types carry no JSON attributes.
• Ais.Net.Models.Json.Specs — 24 round-trip / discriminator / null-omission / buffer-writer / enum-format / extension-member tests.
• Ais.Net.Models.Json.Benchmarks — MemoryDiagnoser serialize/deserialize benchmarks.
• Full endjin build infrastructure (ZeroFailed build.ps1/.zf, GitVersion, CI workflows, Central Package Management, .editorconfig/stylecop.json, global.json), plus a README.md with usage and the NATS adapter example.

⚠️ CI dependency

This package depends on the Ais.Net.Models 1.0.0 package, which is not yet published (it is in flight as ais-dotnet/Ais.Net.Models#8). CI here will not build until that 1.0.0 release is on NuGet/GitHub Packages.

Verified locally — build succeeds and all 24 tests pass — against a local pack of Ais.Net.Models 1.0.0. Once 1.0.0 is published, run a restore to seed packages.lock.json so CI locked-mode restore works.

🤖 Generated with Claude Code

[Copilot]

Pull request overview

Initial import of Ais.Net.Models.Json, a UTF-8-first, low-allocation System.Text.Json serializer for Ais.Net.Models AIS message types, using a $type discriminator for polymorphic round-tripping, plus accompanying specs, benchmarks, and build/CI scaffolding.

Changes:

• Added the AisMessageJson static API, source-generation context, and C# extension members for UTF-8 JSON serialization/deserialization.
• Added MSTest specs validating round-tripping, discriminator behavior, null omission, buffer-writer output, and enum formatting; plus BenchmarkDotNet benchmarks.
• Added build infrastructure (ZeroFailed/Endjin), central package management, GitHub Actions workflows, and documentation/licensing.

Reviewed changes

Copilot reviewed 25 out of 27 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
Solutions/stylecop.json	Adds StyleCop analyzer settings file required by Endjin tooling.
Solutions/Directory.Packages.props	Enables Central Package Management and pins package versions.
Solutions/Ais.Net.Models.Json/AisMessageJsonExtensions.cs	Adds C# extension members over AisMessageJson for ergonomics.
Solutions/Ais.Net.Models.Json/AisMessageJsonContext.cs	Adds STJ source-generated context for reflection-free metadata.
Solutions/Ais.Net.Models.Json/AisMessageJson.cs	Implements polymorphic UTF-8 JSON serialization/deserialization with $type discriminator.
Solutions/Ais.Net.Models.Json/Ais.Net.Models.Json.csproj	Adds the main library project targeting net10.0 with packaging metadata.
Solutions/Ais.Net.Models.Json.Specs/AssemblyInfo.cs	Configures MSTest parallelization.
Solutions/Ais.Net.Models.Json.Specs/AisMessageJsonTests.cs	Adds serialization/deserialization specs for discriminator/null omission/buffer writer/etc.
Solutions/Ais.Net.Models.Json.Specs/Ais.Net.Models.Json.Specs.csproj	Adds the specs project and restore lock configuration.
Solutions/Ais.Net.Models.Json.slnx	Adds solution definition including library/specs/benchmarks projects.
Solutions/Ais.Net.Models.Json.Benchmarks/Program.cs	Adds BenchmarkDotNet entrypoint using BenchmarkSwitcher.
Solutions/Ais.Net.Models.Json.Benchmarks/JsonSerializationBenchmarks.cs	Adds benchmarks for byte array vs buffer writer vs pooled writer paths, plus deserialization.
Solutions/Ais.Net.Models.Json.Benchmarks/Ais.Net.Models.Json.Benchmarks.csproj	Adds the benchmarks project referencing the library.
Solutions/.editorconfig	Adds repo formatting/analyzer configuration.
README.md	Adds usage docs and NATS adapter example.
LICENSE	Adds Apache 2.0 license text.
imm.yaml	Adds engineering standards/metadata file.
global.json	Pins .NET SDK and MSTest SDK version.
GitVersion.yml	Adds GitVersion configuration.
build.ps1	Adds ZeroFailed/InvokeBuild-based build entrypoint script.
.zf/config.ps1	Adds ZeroFailed build configuration and solution selection.
.gitignore	Adds Visual Studio/.NET ignore rules and build artifact ignores.
.github/workflows/dependabot_approve_and_label.yml	Adds Dependabot automation workflow.
.github/workflows/build.yml	Adds CI build workflow using Endjin reusable pipeline.
.github/workflows/auto_release.yml	Adds auto-release/tagging workflow logic.
.gitattributes	Adds line-ending/text normalization rules.

Comments suppressed due to low confidence (1)

.github/workflows/build.yml:62

• The reusable workflow is referenced at @main, which makes the pipeline non-reproducible and introduces supply-chain risk (upstream changes can affect your builds without a PR here). Consider pinning to a specific tag or commit SHA.

  build:
    needs: prepareConfig
    uses: endjin/Endjin.RecommendedPractices.GitHubActions/.github/workflows/scripted-build-matrix-pipeline.yml@main
    with:

---

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Test Results

24 tests   24 ✅  0s ⏱️
 1 suites   0 💤
 1 files     0 ❌

Results for commit bd6c92b.

♻️ This comment has been updated with latest results.

[HowardvanRooijen]

Thanks for the review — dispositions below:

1. .editorconfig invalid csharp_new_line_before_open_brace value — ✅ Fixed in bd6c92b. Replaced the invalid object_collection / typo'd object_collection_array_initalizers tokens with the valid object_collection_array_initializers.

2. RestoreLockedMode with no packages.lock.json — ✅ Added in a1ef60b. The lock file couldn't be generated until the Ais.Net.Models dependency was published; it's now committed against the published package.

3. Pinned to Ais.Net.Models 1.0.0 (not on the feed) — ✅ Bumped to 1.0.1 in 86c9270. 1.0.0 was tagged but failed NuGet validation; 1.0.1 is the first published 1.x and is now on nuget.org. Verified locally: restore + build + all 24 tests pass against the published package.

4 & 5. @main on the endjin GitHub Actions and the ZeroFailed build extension — Intentional, left as-is. Tracking @main for endjin's own first-party actions (endjin/Endjin.RecommendedPractices.GitHubActions) and the ZeroFailed.Build.DotNet extension is the established pattern across the endjin ecosystem (and matches the Ais.Net.Models core repo) — it's how these repos receive continuous, bot-managed updates. Third-party/GitHub actions (e.g. actions/checkout) remain SHA-pinned, which is the deliberate distinction: pin external, track first-party. Changing these would diverge from the org convention and break the auto-update flow.