fix(test): disconnect Hopper fixture IPC on SIGTERM

tests/boundary/providers/hopper/hopperClient.cleanup.test.ts

@@ -127,6 +127,34 @@ describe("HopperClient cleanup", () => {
     await first;
   });
 
+  it("exits an IPC-backed fixture cleanly after cancelling active work", async () => {
+    const launcher = new FixtureLauncher();
+    const client = await startClient(launcher);
+    const controller = new AbortController();
+    const pending = client.callTool(
+      "echo",
+      { gate: "cancel-and-close" },
+      {
+        signal: controller.signal,
+      },
+    );
+    await launcher.waitForRequest("echo", "cancel-and-close");
+    controller.abort();
+    await expect(pending).resolves.toMatchObject({
+      ok: false,
+      error: { _tag: "HopperCancelledError" },
+    });
+    await client.close();
+    const child = launcher.processes.at(-1);
+    expect({
+      exitCode: child?.exitCode,
+      signalCode: child?.signalCode,
+    }).toEqual({
+      exitCode: 0,
+      signalCode: null,
+    });
+  });
+
   it("reports unconfirmed unowned document cleanup as a typed close failure", async () => {
     const client = new HopperClient({
       launcher: new UnconfirmedFixtureLauncher(),

tests/boundary/providers/hopper/hopperClient.protocol.test.ts

@@ -113,6 +113,17 @@ describe("HopperClient protocol", () => {
           requestId: (await launcher.waitForRequest(method)).id,
         });
     }
+    if (expectedTag === "HopperProtocolError") {
+      await client.close();
+      const child = launcher.processes.at(-1);
+      expect({
+        exitCode: child?.exitCode,
+        signalCode: child?.signalCode,
+      }).toEqual({
+        exitCode: 0,
+        signalCode: null,
+      });
+    }
   });
 
   it("preserves a sanitized bridge exception diagnostic", async () => {

tests/fixtures/fakeHopper.mjs

@@ -184,14 +184,7 @@ const server = createServer((socket) => {
         request.method === "shutdown_document"
       ) {
         send({ id: request.id, result: shutdownResult() });
-        if (shutdownMode !== "cleanup-required")
-          setTimeout(
-            () =>
-              server.close(() => {
-                if (process.connected) process.disconnect();
-              }),
-            2,
-          );
+        if (shutdownMode !== "cleanup-required") setTimeout(closeServer, 2);
       } else if (request.method === "hang") {
         // Deliberately leave the request pending.
       } else if (request.method === "exit") {
@@ -234,5 +227,10 @@ const server = createServer((socket) => {
   });
 });
 
+const closeServer = () =>
+  server.close(() => {
+    if (process.connected) process.disconnect();
+  });
+
 server.listen(socketPath);
-process.on("SIGTERM", () => server.close());
+process.on("SIGTERM", closeServer);