@systemfsoftware/stryker-js-plugin-runtime

The mutation-testing plugin runtime — the worker-side implementation of the boundary described by @systemfsoftware/stryker-js-plugin-interface. A plugin's main.ts launches this package's workerServerLayer; nothing here is contract, so a host that only spawns plugins never imports it.

This package owns:

• the worker RPC server layer a plugin process launches — workerServerLayer and its WorkerServerParams;
• the telemetry a worker process exports with — the WorkerTelemetryConfig shape and the OTLP endpoint rule TracesUrl in worker-telemetry.schema.ts, read through the WorkerTelemetry service a worker's program root binds its own OTel SDK from;
• the worker-options wire schema — WorkerOptionsWire — and the WorkerOptions service a worker reads its options.json through;
• the trace-context middleware implementations that carry W3C traceparent/tracestate across the process split — layerTraceContextClient, layerTraceContextServer, withLinkedSpan, tracePartsOf, partsOfEffectSpan.

The symbols these implement — the RPC groups, the payload schemas, the typed errors, the spawn contract, and the trace-context contract (TraceContextMiddleware, PropagatedTrace, TracedRpc) — are owned by @systemfsoftware/stryker-js-plugin-interface and re-exported by nothing: a consumer imports each symbol from the package that owns it.

Install

pnpm add @systemfsoftware/stryker-js-plugin-runtime

The entry a plugin ships

Worker.workerServerLayer builds the RpcServer for one kind's RPC group over a socket, file system, and path the program root provides, restricts the socket file to its owner, and provides the server-side trace-context middleware:

import { Plugin } from '@systemfsoftware/stryker-js-plugin-interface'
import { Worker } from '@systemfsoftware/stryker-js-plugin-runtime'

NodeRuntime.runMain(
  Layer.launch(
    Worker.workerServerLayer({
      rpcs: Plugin.TestRunnerRpcs,
      handlers: testRunnerHandlers,
      schemaServices: Layer.empty,
    }),
  ).pipe(Effect.provideService(Logger.LogToStderr, true)),
)

Worker options

The host writes the run's options to options.json in the worker directory it creates; Worker.WorkerOptions, read through Worker.WorkerOptions.layer, decodes that file into the same StrykerOptions a local stryker run uses, so a worker's handlers see the run's options without the host passing them over the wire.

Trace context

A synchronous RPC call is the parent of the spans it invokes: the client middleware injects the active trace context into the request headers as W3C traceparent/tracestate, and the server middleware continues that trace for the handler. Asynchronous plugin work — anything that outlives its call — is linked instead of parented, through Trace.withLinkedSpan.

License

Apache-2.0. Part of systemfsoftware.