ffi-testing

name	ffi-testing
description	Test changes to the TAV C, WASM, and C# FFI surfaces. Use when exported functions, handles, constants, ownership rules, errors, goldens, or consumer tests change under ffi/.
argument-hint	[c|wasm|csharp] [utils|snp|cose|caci]

FFI testing

Treat each consumer suite as an external user of its public surface.

Required coverage

1. Enumerate the complete changed public surface from its authoritative source:
   • C: ffi/include/tav/*.h
   • WASM: exported items in ffi/src/wasm_ffi
   • C#: public types and members under ffi/csharp/TeeAttestationVerification
2. Exercise every matching function, property, enum member, and ownership operation in the corresponding consumer suite.
3. Assert behavior with known values or negative cases; successful invocation alone is insufficient.
4. Test owned handles, borrowed byte views, null/error behavior, and out-parameter reset rules where applicable.
5. Update goldens only alongside behavioral tests.

ABI constants

When constants change:

1. Keep explicit test mappings between compiled Rust constants and their C names. Compare values and exact name sets in both directions.
2. For constants exposed in C#, keep explicit C-name-to-managed-name mappings. Parse the public C header and compare values and exact member sets with the reflected managed enum.
3. Reject missing, extra, duplicate, or mismatched members. Do not update only one side to make a test pass.
4. Use named Rust constants in runtime logic and tests; do not repeat numeric literals in match arms and equivalence tests.
5. Keep function signatures, handle ownership, and boolean/layout checks outside constant-equivalence tests.

Validation

Use half-machine concurrency for builds.

• Native Rust: crypto_openssl
• C consumer: shared and static
• WASM consumer: crypto_webcrypto
• C#: python3 ffi/csharp/run_tests.py --configuration Release
• Repository: formatting, version sync, license headers, and git diff --check