fix(gateway): restart watch after child sigterm

scripts/watch-node.mjs

@@ -8,6 +8,8 @@ import { isRestartRelevantRunNodePath, runNodeWatchedPaths } from "./run-node.mj
 
 const WATCH_NODE_RUNNER = "scripts/run-node.mjs";
 const WATCH_RESTART_SIGNAL = "SIGTERM";
+const WATCH_RESTARTABLE_CHILD_EXIT_CODES = new Set([143]);
+const WATCH_RESTARTABLE_CHILD_SIGNALS = new Set(["SIGTERM"]);
 
 const buildRunnerArgs = (args) => [WATCH_NODE_RUNNER, ...args];
 
@@ -27,6 +29,10 @@ const resolveRepoPath = (filePath, cwd) => {
 const isIgnoredWatchPath = (filePath, cwd) =>
   !isRestartRelevantRunNodePath(resolveRepoPath(filePath, cwd));
 
+const shouldRestartAfterChildExit = (exitCode, exitSignal) =>
+  (typeof exitCode === "number" && WATCH_RESTARTABLE_CHILD_EXIT_CODES.has(exitCode)) ||
+  (typeof exitSignal === "string" && WATCH_RESTARTABLE_CHILD_SIGNALS.has(exitSignal));
+
 export async function runWatchMain(params = {}) {
   const deps = {
     spawn: params.spawn ?? spawn,
@@ -90,7 +96,7 @@ export async function runWatchMain(params = {}) {
         if (shuttingDown) {
           return;
         }
-        if (restartRequested) {
+        if (restartRequested || shouldRestartAfterChildExit(exitCode, exitSignal)) {
           restartRequested = false;
           startRunner();
           return;

src/infra/watch-node.test.ts

@@ -147,6 +147,38 @@ describe("watch-node script", () => {
     expect(fakeProcess.listenerCount("SIGTERM")).toBe(0);
   });
 
+  it("restarts when the runner exits with a SIGTERM-derived code unexpectedly", async () => {
+    const childA = Object.assign(new EventEmitter(), {
+      kill: vi.fn(),
+    });
+    const childB = Object.assign(new EventEmitter(), {
+      kill: vi.fn(() => {}),
+    });
+    const spawn = vi.fn().mockReturnValueOnce(childA).mockReturnValueOnce(childB);
+    const watcher = Object.assign(new EventEmitter(), {
+      close: vi.fn(async () => {}),
+    });
+    const createWatcher = vi.fn(() => watcher);
+    const fakeProcess = createFakeProcess();
+
+    const runPromise = runWatchMain({
+      args: ["gateway", "--force"],
+      createWatcher,
+      process: fakeProcess,
+      spawn,
+    });
+
+    childA.emit("exit", 143, null);
+    await new Promise((resolve) => setImmediate(resolve));
+    expect(spawn).toHaveBeenCalledTimes(2);
+
+    fakeProcess.emit("SIGINT");
+    const exitCode = await runPromise;
+    expect(exitCode).toBe(130);
+    expect(childB.kill).toHaveBeenCalledWith("SIGTERM");
+    expect(watcher.close).toHaveBeenCalledTimes(1);
+  });
+
   it("forces no-respawn for watch children even when supervisor hints are inherited", async () => {
     const { child, spawn, watcher, createWatcher, fakeProcess } = createWatchHarness();