Stage 3 test report

Recorded 2026-11-04 after the commands below. GitHub Actions has not been run from this machine. Linux x86_64 is configured as a required decode job and is untested here.

Environment

The eight earlier .f3 fixtures were not regenerated. custom_wasm.f3 was added. It is 10_663_647 bytes, SHA-256 70beae4fedc5825d3de83e0ff0a117712283138afcdfee610da7f6d800eb6c8b. The embedded module is 10_661_135 bytes, so the hard module cap is 16 MiB. A 8 MiB cap would reject this file.

Wasm build

The first link used Homebrew clang as CARGO_TARGET_WASM32_WASIP1_LINKER. zstd-sys compiled. The link failed:

rust-lld: error: entry symbol not defined (pass --no-entry to suppress): _initialize

The retry kept CC_wasm32_wasip1 on Homebrew clang and WASI_SYSROOT=/opt/homebrew/opt/wasi-libc/share/wasi-sysroot, and left the Wasm link to nightly-2025-02-24. That build finished. fff-ude-example-fff.wasm exports FFFUDE_VERSION_1_0 and decode_general_ffi.

tmp/upstream-f3/target/release/f3_fixture_gen then wrote every fixture into /tmp/f3-stage3-fixtures. Only custom_wasm.f3 was copied into test/fixtures/. The upstream dump_rows example wrote custom_wasm_rows.json with trade_id 1, 2, and 3.

Host

cargo check of native/f3_native on nightly-2025-11-15 compiled Wasmtime 28. The Vortex nightly was not changed. F3_BUILD_NATIVE=1 MIX_ENV=test mix compile --force produced the NIF.

Fuel is 5_000_000 instructions. Upstream sets none. Linear memory is 8 MiB. The built-in module grows a table to 3308 elements, so the table-element cap is 16_384. An omitted wasm_id is FlatBuffers default 0. This file omits it and has one module.

Commands

brew install wasi-libc wasi-runtimes
# wasi-libc 34, wasi-runtimes 23.1.5, llvm 23.1.5

cargo build --locked -p fff-ude-example-fff --target wasm32-wasip1 --profile opt-size-lvl3
# nightly-2025-02-24, WASI_SYSROOT set, rustc linker

f3_fixture_gen --upstream tmp/upstream-f3 --out /tmp/f3-stage3-fixtures
cargo run --release --example dump_rows -- /tmp/f3-stage3-rows /tmp/f3-stage3-fixtures/custom_wasm.f3

F3_BUILD_NATIVE=1 mix test --only native
6 passed

mix compile --force
mix ci
77 passed (3 doctests, 74 tests), 6 native tests excluded
coverage 92.30%
mix credo --strict found no issues

mix test --only native included the sandboxed read of custom_wasm.f3. Those rows match the manifest and test/fixtures/golden/custom_wasm_rows.json. The same run rejects a short buffer, fuel exhaustion, a 16 MiB memory minimum, a memory grow, path_open, sock_accept, a missing ABI symbol, and major 2. No throughput or RSS numbers were collected.

Default F3.read/2 and F3.stream/2 on custom_wasm.f3 return :unsupported_encoding and do not pread the WASMBinaries section. lib_urls are not walked. A trace of :httpc during the sandboxed read received no calls.