Settle failed MySQL readiness probes

Author: chubes4

packages/cli/src/runtime-services.ts

@@ -197,17 +197,29 @@ export async function waitForMysqlProtocol(host: string, port: number, timeoutMs
 function mysqlHandshake(host: string, port: number, signal?: AbortSignal): Promise<void> {
   return new Promise((resolve, reject) => {
     const socket = createConnection({ host, port })
+    let settled = false
     const timer = setTimeout(() => socket.destroy(new Error("connection timeout")), 1_000)
     const abort = () => socket.destroy(new Error("aborted"))
+    const fail = (error: Error) => {
+      if (settled) return
+      settled = true
+      reject(error)
+    }
     signal?.addEventListener("abort", abort, { once: true })
-    socket.once("error", reject)
+    socket.once("error", fail)
     socket.once("data", (chunk: Buffer) => {
+      if (settled) return
+      settled = true
       clearTimeout(timer)
       socket.destroy()
       if (chunk.length < 5 || chunk[4] !== 10) reject(new Error("invalid MySQL protocol handshake"))
       else resolve()
     })
-    socket.once("close", () => { clearTimeout(timer); signal?.removeEventListener("abort", abort) })
+    socket.once("close", () => {
+      clearTimeout(timer)
+      signal?.removeEventListener("abort", abort)
+      fail(new Error("connection closed before MySQL protocol handshake"))
+    })
   })
 }
 

tests/runtime-services.test.ts

@@ -22,6 +22,13 @@ await waitForMysqlProtocol("127.0.0.1", address.port, 250)
 await new Promise<void>((resolve) => server.close(() => resolve()))
 await assert.rejects(waitForMysqlProtocol("127.0.0.1", address.port, 25), /readiness timed out/)
 
+const closingServer = createServer((socket) => socket.end())
+await new Promise<void>((resolve) => closingServer.listen(0, "127.0.0.1", resolve))
+const closingAddress = closingServer.address()
+assert.ok(closingAddress && typeof closingAddress !== "string")
+await assert.rejects(waitForMysqlProtocol("127.0.0.1", closingAddress.port, 25), /readiness timed out/, "a pre-handshake close remains retryable instead of leaving an unsettled promise")
+await new Promise<void>((resolve) => closingServer.close(() => resolve()))
+
 const calls: Array<{ args: string[]; env?: NodeJS.ProcessEnv; signal?: AbortSignal }> = []
 const dependencies: RuntimeServiceDependencies = {
   randomBytes: (size) => Buffer.alloc(size, 7),