Structure SSE update patches

web/src/utils/formatRunnerSpawnError.ts

@@ -1,8 +1,24 @@
 import type { Machine } from '../types/api'
 
+function getLastSpawnError(runnerState: unknown): { message: string; at?: number } | null {
+    if (!runnerState || typeof runnerState !== 'object' || Array.isArray(runnerState)) {
+        return null
+    }
+    const lastSpawnError = (runnerState as { lastSpawnError?: unknown }).lastSpawnError
+    if (!lastSpawnError || typeof lastSpawnError !== 'object' || Array.isArray(lastSpawnError)) {
+        return null
+    }
+    const message = (lastSpawnError as { message?: unknown }).message
+    if (typeof message !== 'string' || message.length === 0) {
+        return null
+    }
+    const at = (lastSpawnError as { at?: unknown }).at
+    return typeof at === 'number' ? { message, at } : { message }
+}
+
 export function formatRunnerSpawnError(machine: Machine | null): string | null {
-    const lastSpawnError = machine?.runnerState?.lastSpawnError
-    if (!lastSpawnError?.message) {
+    const lastSpawnError = getLastSpawnError(machine?.runnerState)
+    if (!lastSpawnError) {
         return null
     }