Native Guid <> UUID

[buvinghausen]

Add native Guid ↔ Python uuid.UUID support

Adds first-class support for System.Guid as a native interop type, mapping to and from Python's uuid.UUID. No manual string conversion or PyObject unwrapping is needed.

Usage

Python:

import uuid

def create_token() -> uuid.UUID:
    return uuid.uuid4()

def echo_id(value: uuid.UUID) -> uuid.UUID:
    return value

C#:

Guid token = module.CreateToken();
Guid same  = module.EchoId(Guid.NewGuid());

---

How it works

The conversion goes through Python's standard uuid module (always available in the stdlib):

• C# → Python: PyObject.From(Guid) calls uuid.UUID(guid.ToString()) via the C API
• Python → C#: PyObjectImporters.Uuid calls str(uuid_obj) and parses the result with Guid.Parse

Both directions use the canonical xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx string representation, which both Guid.ToString() and str(uuid.UUID(...)) produce by default.

---

Changes

Source generation (CSnakes.SourceGeneration)

File	Change
Parser/Types/PythonTypeSpec.cs	Added UuidType record and PythonTypeSpec.Uuid static instance
Parser/PythonParser.TypeDef.cs	Parser now recognises UUID and uuid.UUID as UuidType
Reflection/TypeReflection.cs	UuidType maps to Guid in both ToPython and FromPython directions
ResultConversionCodeGenerator.cs	Added UuidType case generating .BareImportAs<Guid, PyObjectImporters.Uuid>()

Generated signature for a uuid.UUID return type:

Guid TestUuidRoundtrip(Guid value);

Runtime (CSnakes.Runtime)

File	Change
PyObjectTypeConverter.Uuid.cs (new)	ConvertFromGuid / ConvertToGuid conversion logic
Python/PyObjectImporters.cs	Added Uuid importer
Python/PyObject.cs	Added From(Guid), From(Guid?) overloads; Guid case in From(object?) and As<T>
PublicAPI/net8.0/PublicAPI.Unshipped.txt	Declared new public API surface
PublicAPI/net9.0/PublicAPI.Unshipped.txt	Declared new public API surface

Tests

File	What it covers
CSnakes.Runtime.Tests/Converter/GuidConverterTest.cs (new)	Round-trip via PyObject.From / As<Guid> and the Uuid importer
CSnakes.Tests/PythonTypeDefinitionParserTests.cs	Parser accepts both UUID and uuid.UUID
CSnakes.Tests/TypeReflectionTests.cs	Both spellings resolve to Guid
CSnakes.Tests/PythonStaticGeneratorTests/FormatClassFromMethods.test_uuid.approved.txt (new)	Source generator snapshot
Integration.Tests/python/test_uuid.py (new)	Python test module
Integration.Tests/UuidTests.cs (new)	End-to-end integration tests

[Copilot]

Pull request overview

Adds first-class interop support for mapping Python uuid.UUID values to/from .NET System.Guid, so generated bindings and runtime conversions no longer require manual string conversion or PyObject handling.

Changes:

• Extend the source generator type system and parser to recognize UUID / uuid.UUID and reflect it as Guid.
• Add runtime conversion + importer support (PyObject.From(Guid) / As<Guid> and PyObjectImporters.Uuid).
• Add unit + integration tests and generator snapshot coverage for UUID/Guid round-tripping.

Reviewed changes

Copilot reviewed 15 out of 15 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
src/Integration.Tests/python/test_uuid.py	Adds Python functions returning/accepting uuid.UUID for end-to-end integration coverage.
src/Integration.Tests/UuidTests.cs	Adds integration tests validating Guid ↔ UUID conversion and parsing from string.
src/CSnakes.Tests/TypeReflectionTests.cs	Verifies UUID and uuid.UUID resolve to Guid in reflection mapping.
src/CSnakes.Tests/PythonTypeDefinitionParserTests.cs	Verifies the parser accepts both UUID and uuid.UUID.
src/CSnakes.Tests/PythonStaticGeneratorTests/FormatClassFromMethods.test_uuid.approved.txt	Snapshot showing generated signatures and return conversion using the UUID importer.
src/CSnakes.SourceGeneration/ResultConversionCodeGenerator.cs	Adds UUID result conversion generator case targeting Guid + PyObjectImporters.Uuid.
src/CSnakes.SourceGeneration/Reflection/TypeReflection.cs	Maps UuidType to Guid in both conversion directions.
src/CSnakes.SourceGeneration/Parser/Types/PythonTypeSpec.cs	Introduces UuidType and PythonTypeSpec.Uuid.
src/CSnakes.SourceGeneration/Parser/PythonParser.TypeDef.cs	Recognizes UUID / uuid.UUID as UuidType.
src/CSnakes.Runtime/Python/PyObjectImporters.cs	Adds PyObjectImporters.Uuid importer for Guid.
src/CSnakes.Runtime/Python/PyObject.cs	Adds PyObject.From(Guid/Guid?), Guid case in From(object?), and As<Guid> support.
src/CSnakes.Runtime/PyObjectTypeConverter.Uuid.cs	Implements the actual Guid ↔ uuid.UUID conversion logic.
src/CSnakes.Runtime/PublicAPI/net8.0/PublicAPI.Unshipped.txt	Declares newly added public API members for net8.0.
src/CSnakes.Runtime/PublicAPI/net9.0/PublicAPI.Unshipped.txt	Declares newly added public API members for net9.0.
src/CSnakes.Runtime.Tests/Converter/GuidConverterTest.cs	Adds runtime converter tests for multiple Guid cases.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[buvinghausen]

@atifaziz or @tonybaloney y'all still around?