Conformance

Correctness here is a pass count against somebody else’s suite, not a claim.

Suite	Source	Result
Core spec tests	WebAssembly/testsuite + the proposal repos	13 corpora, 711 generated case files, no skip list; the 3.0 corpus runs on both engines.
Component Model async	the official async .wast suites	31 suites, 0 skipped, 0 failed.
Canonical ABI values	the official test/values suites	7 suites, 0 skipped, 0 failed, through wasm-tools json-from-wast. Every vendored module instantiates — see below.
wasi-testsuite	WebAssembly/wasi-testsuite	AssemblyScript, C and Rust, no skipped tests, on Linux, macOS and Windows, through the wazy CLI.
Cross-proposal interaction	wasmtime’s tests/misc_testsuite	9 .wast vendored from wasmtime, beside 5 written here.

go test ./internal/integration_test/spectest/...  # core spec corpora
go test ./internal/component/...                  # component ABI + async .wast

The skip list is empty, and the harness fails if that changes

wastKnownSkips in internal/component/instance/wast_conformance_test.go is an empty map: every vendored module of all 7 suites instantiates. The harness fails if the observed set differs in either direction — a new entry is a regression, and a stale one means a gap closed and the list must shrink. An empty list is therefore an assertion the test enforces, not a claim made here.

The last four entries — types.11, fused.22, fused.23 and resources.14 — were all the same gap: a nested component naming a definition an enclosing component owns. Closing them meant modelling the core-module and component index spaces separately (this package had equated each with a single binary section), adding a decode-time outer link so alias outer resolves, accepting an instance-sort instantiate argument that names an imported instance — plus, for fused.22’s second and unrelated half, masking flags to their label count on lift.

The mechanism exists because a silent skip once hid a bug: the harness used to only log a skip, which made buildPassthroughShim rejecting an empty export name invisible — the official suite reproduced the reporter’s failure all along and still reported PASS (#25).

Beyond the suites

• A separate workflow runs the Zig standard-library test binary, the Go wasip1 standard-library tests on two Go versions, and libsodium’s suite, on every push.
• A differential trace-oracle byte-compares the async runtime against the specification’s reference implementation (definitions.py).
• Four fuzz targets run in CI — three differential against the interpreter, one for validation.

One official async fixture is broken upstream; the 31/31 runs against a corrected copy, and the fix is filed as component-model#679.

Wasm 3.0

There is no separate 3.0 suite in the specification repository — WebAssembly/testsuite@main is it. wazy generates its corpus from that tree, and the 3.0 cases run on both the compiler and the interpreter. The cross-proposal cases in internal/integration_test/spectest/v3-interaction named wasmtime-*.wast are vendored from wasmtime’s tests/misc_testsuite; the wazy-*.wast beside them are this repository’s.