fix(qa-lab): guard stream listeners against possibly-null child stdio

wangmiao0668000666 · wangmiao0668000666 · commit 914b9a81e33b · 2026-07-09T10:32:49.000+08:00
The attachGatewayChildStreamErrorHandlers helper called `child.stdout.on("error", ...)` directly, but `node:child_process` types `child.stdout` as `Readable | null`. PR-head check-prod-types, check-test-types, and check-additional-extension-package-boundary all failed with TS18047 ('child.stdout' is possibly 'null'). Add the existing `?.` chain so the listener only attaches when the pipe is present; this matches the production stdio shape used at the spawn site (`["ignore", "pipe", "pipe"]`, which guarantees the pipes exist at runtime). 🤖 Generated with [Claude Code](https://claude.com/claude-code)
diff --git a/extensions/qa-lab/src/gateway-child.ts b/extensions/qa-lab/src/gateway-child.ts
@@ -416,8 +416,8 @@ function attachGatewayChildStreamErrorHandlers(
       child.kill("SIGTERM");
     }
   };
-  child.stdout.on("error", handleStreamError("stdout"));
-  child.stderr.on("error", handleStreamError("stderr"));
+  child.stdout?.on("error", handleStreamError("stdout"));
+  child.stderr?.on("error", handleStreamError("stderr"));
 }
 
 function monitorQaGatewayChildSpawnError(

Original file line number	Diff line number	Diff line change
`@@ -416,8 +416,8 @@ function attachGatewayChildStreamErrorHandlers(`
`416`	`416`	`child.kill("SIGTERM");`
`417`	`417`	`}`
`418`	`418`	`};`
`419`		`- child.stdout.on("error", handleStreamError("stdout"));`
`420`		`- child.stderr.on("error", handleStreamError("stderr"));`
	`419`	`+ child.stdout?.on("error", handleStreamError("stdout"));`
	`420`	`+ child.stderr?.on("error", handleStreamError("stderr"));`
`421`	`421`	`}`
`422`	`422`
`423`	`423`	`function monitorQaGatewayChildSpawnError(`