Add source-generator support for byte property round-trip in typed mappers

[Copilot]

byte properties in typed DocumentDbContext models were not being mapped by the source-generated serializer/deserializer, so persisted values (e.g. SlaveAddress = 8) were read back as default 0. This change adds explicit byte mapping in generated mappers and covers nullable/non-nullable byte round-trip behavior.

• Mapper generation: primitive type support

  • CodeGenerator.GetPrimitiveWriteMethod now maps byte to WriteInt32.
  • CodeGenerator.GetPrimitiveReadMethod now maps byte to ReadInt32Coerced.
  • CodeGenerator.IsValueType now recognizes byte for nullable unwrapping paths.

• Mapper generation: deserialization correctness

  • Generated read path now casts coerced numeric reads back to byte ((byte)), aligning stored BSON numeric values with CLR byte properties.
  • Byte type checks were tightened to exact byte matches to avoid accidental overlap with unrelated numeric type names.

• Regression coverage

  • Added a dedicated typed entity with byte and byte? fields and corresponding context registration.
  • Added focused round-trip tests for:
    • non-null byte + non-null byte?
    • non-null byte + null byte?

public class ByteEntity
{
    public ObjectId Id { get; set; }
    public byte Value { get; set; }
    public byte? OptionalValue { get; set; }
}

• Fixes byte Type not support #137

[Copilot]

Pull request overview

This PR fixes a typed-mapper source generation gap where byte / byte? properties were not correctly round-tripped through the generated BSON serializer/deserializer, causing persisted byte values to be read back as 0.

Changes:

• Added byte support to the source generator’s primitive read/write method selection and value-type detection.
• Updated generated read-path emission to cast coerced numeric reads back to byte.
• Added regression tests and a test entity/context registration to validate byte and byte? round-trips (including null).

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
tests/BLite.Tests/BytePropertyTests.cs	Adds regression tests for byte and byte? round-trip behavior.
tests/BLite.Shared/TestDbContext.cs	Registers ByteEntity collection and model mapping for typed-context tests.
tests/BLite.Shared/MockEntities.cs	Introduces ByteEntity used by the new tests.
src/BLite.SourceGenerators/CodeGenerator.cs	Extends primitive mapping logic and generated read code to support byte round-trips.

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.