compose

Composition examples

component-test compose-runner suite.wasm -o composed.wasm (and component-test run suite.wasm, which composes in memory and executes) wrap this entire flow with an embedded reference provider and runner core. The raw commands below remain the recipe for custom topologies — SUT providers, negative composition gates, debugging — and are what the wrapper mirrors.

Two-step (canonical): bundle the suite with the reference context provider, then plug the bundle into a runner core.

cargo build --target wasm32-wasip2 --release -p sample-suite -p provider -p runner-cli
wac compose \
  -d polymorph:provider-impl=../../target/wasm32-wasip2/release/provider.wasm \
  -d polymorph:sample-suite=../../target/wasm32-wasip2/release/sample_suite.wasm \
  -o bundle.wasm bundle.wac
wac plug --plug bundle.wasm ../../target/wasm32-wasip2/release/runner_cli.wasm -o composed.wasm
wasmtime run -W component-model-async -S p3 composed.wasm

--env COMPONENT_TEST_JSONL=1 (wasmtime does not inherit host env vars) switches the composed runner to the results wire format; fold it with component-test fold:

wasmtime run -W component-model-async -S p3 --env COMPONENT_TEST_JSONL=1 composed.wasm \
  | component-test fold ../../components/sample-suite/tests.lock

This runner is execute-everything: wac strips the tags custom section (findings #14), so it cannot apply feature-tag scheduling. Its envelope says so ("scheduling":"none"), and component-test aggregate applies applicability for such streams from the lockfile + target manifest — executed non-applicable cases are reclassified to not-applicable, matching the host-embed runner's output shape (see examples/aggregate/).

compose.wac is the equivalent one-shot three-node composition.

Note: wac plug alone cannot build the bundle — it drops the provider's factory/test-context re-exports, and the result fails runner linking with type mismatch in instance export 'context' (see docs/findings.md). Custom sections (the tags inventory) are stripped by wac compose: generate lockfiles from the suite artifact, not the bundle.