Harden bridge broker restart (#862)

tests/server/agent-bridge-manager.test.ts

@@ -1,4 +1,5 @@
 import { chmodSync, mkdirSync, mkdtempSync, rmSync, writeFileSync } from 'fs'
+import { createServer, type Server } from 'net'
 import { tmpdir } from 'os'
 import { join } from 'path'
 import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
@@ -74,4 +75,36 @@ describe('agent bridge manager command resolution', () => {
     expect(DEFAULT_AGENT_BRIDGE_ENDPOINT).toContain(`hermes-agent-bridge-test-${process.pid}`)
     expect(DEFAULT_AGENT_BRIDGE_ENDPOINT).not.toBe('ipc:///tmp/hermes-agent-bridge.sock')
   })
+
+  it('waits briefly for a restarting bridge socket before failing', async () => {
+    const endpoint = process.platform === 'win32'
+      ? `tcp://127.0.0.1:${32000 + (process.pid % 10000)}`
+      : `ipc://${join(tempDir, 'late-bridge.sock')}`
+    let server: Server | undefined
+
+    const ready = new Promise<void>((resolve) => {
+      setTimeout(() => {
+        server = createServer((socket) => {
+          socket.once('data', () => {
+            socket.end(`${JSON.stringify({ ok: true, pong: true })}\n`)
+          })
+        })
+        if (endpoint.startsWith('ipc://')) {
+          server.listen(endpoint.slice('ipc://'.length), resolve)
+        } else {
+          const url = new URL(endpoint)
+          server.listen(Number(url.port), url.hostname, resolve)
+        }
+      }, 150)
+    })
+
+    try {
+      const { AgentBridgeClient } = await import('../../packages/server/src/services/hermes/agent-bridge/client')
+      const client = new AgentBridgeClient({ endpoint, connectRetryMs: 1000, timeoutMs: 1000 })
+      await expect(client.ping()).resolves.toMatchObject({ ok: true, pong: true })
+      await ready
+    } finally {
+      await new Promise<void>((resolve) => server?.close(() => resolve()) ?? resolve())
+    }
+  })
 })