fix(ipc-runtime): terminate a wasm main worker that fails to start

ipc-runtime/ts/src/wasm/backend.ts

@@ -353,7 +353,12 @@ export class WasmFfiBackend implements IpcClientAsync {
         entry: opts.entry,
       },
     });
-    await ready;
+    try {
+      await ready;
+    } catch (e) {
+      await worker.terminate();
+      throw e;
+    }
     return backend;
   }
 

ipc-runtime/ts/src/wasm_backend.test.ts

@@ -1,6 +1,7 @@
 import assert from "node:assert/strict";
 import { test } from "node:test";
 import { createWasmFfiBackend } from "./wasm/node/index.js";
+import type { WorkerHandle } from "./wasm/platform.js";
 
 const I32 = 0x7f;
 const leb = (n: number) => {
@@ -135,3 +136,20 @@ test("a worker-mode backend starts the threads its module spawns (node)", async
     await backend.destroy();
   }
 });
+
+test("a backend terminates a main worker that fails to start", async () => {
+  const handlers: ((message: unknown) => void)[] = [];
+  let terminated = false;
+  const worker: WorkerHandle = {
+    postMessage: () => handlers.forEach((h) => h({ type: "init-error", message: "no entry" })),
+    onMessage: (handler) => handlers.push(handler),
+    onError: () => {},
+    terminate: async () => {
+      terminated = true;
+    },
+    unref: () => {},
+  };
+  const module = new Uint8Array([0x00, 0x61, 0x73, 0x6d, 1, 0, 0, 0]);
+  await assert.rejects(createWasmFfiBackend({ module, createMainWorker: () => worker }), /no entry/);
+  assert.equal(terminated, true);
+});