ns-wasm-test

ns-wasm-test

On-device Rstest coverage for @cross-code/ns-wasm3 and @cross-code/ns-wamr. The app runs the shared WebAssembly fixture against the real native runtimes on iOS and Android.

There are two app modes:

• The normal demo entry (app/app.ts) renders the shared WASM checks when you tap RUN.
• The test entry (app/_ns-rstest.ts) displays the optional @cross-code/ns-rstest/ui results page while Rstest executes the specs in a NativeScript Worker.

@cross-code/ns-rstest runs the host loop in Node — discovery, scheduling and reporting — and sends each selected file over a WebSocket to the NativeScript app, where the Worker executes it with Rstest's own runtime. The test entry imports @valor/nativescript-websockets first because NativeScript Core does not provide the browser-compatible WebSocket global used by that host/device connection.

Layout

app/_ns-rstest.ts                    test-only app entry and results UI
app/_ns-rstest.worker.ts             Worker registry for app/tests/**/*.spec.ts
app/tests/wasm3/*.spec.ts           Rstest specs for wasm3
app/tests/wamr/*.spec.ts            Rstest specs for WAMR
app/wasm/fixture-suite.ts           checks shared by specs and demo page
app/wasm/wasm-assets.ts             device paths and platform-aware byte reader
ns-rstest.ios.mts                   iOS simulator host runner
ns-rstest.android.mts               Android emulator host runner
rspack.config.ts                    fixture copies and test-entry/shim setup

The bundler helper changes the bundle entry and aliases bare @rstest/core imports only when --env.rstestNativeScript is present. Production/demo builds still start from app/app.ts and do not include the specs.

Run tests

From the repository root:

pnpm exec nx run ns-wasm-test:typecheck
pnpm exec nx run ns-wasm-test:test.ios
pnpm exec nx run ns-wasm-test:test.android
pnpm exec nx run ns-wasm-test:test.ios.coverage
pnpm exec nx run ns-wasm-test:test.android.coverage

Or from this directory:

pnpm run test.ios
pnpm run test.android
pnpm run test.ios:coverage
pnpm run test.android:coverage

Both host runners launch an emulator/simulator through the project-local NativeScript CLI. They currently use one NativeScript Worker, which keeps native runtime state isolated from the UI thread and avoids concurrent access to plugin/native singletons. Increase workers only for tests known to be thread-safe.

To select a physical device, replace the launchCommand in the relevant host runner with the normal npx ns run <platform> --device <id> arguments and set the coordinator url to a WebSocket address reachable from that device.

Code coverage

Coverage runs execute the same device suite and use Istanbul instrumentation, because NativeScript's JavaScript runtimes do not provide V8 coverage. Passing --coverage automatically adds the coverage-only bundler flag; ordinary test runs stay uninstrumented.

Raw Istanbul data is written separately by platform:

• test-output/rstest/coverage/ios/coverage-final.json
• test-output/rstest/coverage/android/coverage-final.json

Render them with npx nyc report --temp-dir <dir> or hand them to a coverage uploader. The device bundle supplies coverage only for files it actually loads.

Behavioral coverage

Both plugins are tested for:

• all WebAssembly value types, including lossless i64 values beyond 2^53;
• host imports and host return values;
• mutable exported globals;
• shared linear memory;
• loading modules from paths and bytes;
• native error mapping, missing exports, and unlinked imports;
• repeat-safe runtime disposal.

WAMR adds execution-tier, WASI, stack-size, and input-shape coverage. Optional tiers are exercised when available in the native build.

Calls into the fixture go through callFixture(), whose parameters and return values come from the wasm-pack-generated @cross-code/ns-wasm-fixture/types declarations.

Local package wiring

This app intentionally has its own pnpm workspace and node_modules. The five local @cross-code/* dependencies use file: references. If a local package's compiled dist changes, rebuild it through Nx and refresh this app install:

pnpm install --force

Troubleshooting

• Export LANG=en_US.UTF-8 if NativeScript reports a broken CocoaPods setup on macOS.
• Install Android SDK platform 36 if ns doctor cannot find a compatible SDK.
• If an old generated native project contains stale plugin metadata, remove this app's generated platforms/<platform> directory and rerun the target.
• The host and device communicate on port 17878. Do not run the iOS and Android targets concurrently unless they use different ports.
• ns-rstest currently supports one-shot runs; watch/HMR, snapshots, and component testing are not implemented.

See also

• @cross-code/ns-rstest
• Workspace README