Stop reading stdout after last sentinel appears

src/run.ts

@@ -228,13 +228,12 @@ export async function runFile(
     proc.stdin.end()
 
     const totalTimeout = options.timeout * file.commands.length
-    const stdout = await readWithTimeout(proc.stdout, totalTimeout)
+    const lastSentinelSuffix = `_${file.commands.length - 1}__`
+    const stdout = await readUntilSentinel(proc.stdout, sentinel, lastSentinelSuffix, totalTimeout)
     if (!verbose) {
       await readWithTimeout(proc.stderr, 1000).catch(() => "")
     }
 
-    await proc.exited
-
     const { outputs, exitCodes } = parseSentinelOutput(
       stdout,
       sentinel,
@@ -262,6 +261,40 @@ export async function runFile(
   }
 }
 
+async function readUntilSentinel(
+  stream: ReadableStream<Uint8Array>,
+  sentinelPrefix: string,
+  sentinelSuffix: string,
+  timeoutMs: number,
+): Promise<string> {
+  const reader = stream.getReader()
+  const decoder = new TextDecoder()
+  let accumulated = ""
+
+  let timerId: ReturnType<typeof setTimeout>
+  const timeout = new Promise<never>((_, reject) =>
+    timerId = setTimeout(() => reject(new Error("Timeout reading output")), timeoutMs),
+  )
+
+  try {
+    while (true) {
+      const { done, value } = await Promise.race([reader.read(), timeout]) as ReadableStreamReadResult<Uint8Array>
+      if (done) break
+      if (value) {
+        accumulated += decoder.decode(value, { stream: true })
+        // Check if the last sentinel has appeared (prefix + exitcode + suffix)
+        const prefixIdx = accumulated.lastIndexOf(sentinelPrefix)
+        if (prefixIdx !== -1 && accumulated.indexOf(sentinelSuffix, prefixIdx) !== -1) break
+      }
+    }
+  } finally {
+    clearTimeout(timerId!)
+    reader.releaseLock()
+  }
+
+  return accumulated + decoder.decode()
+}
+
 async function readWithTimeout(
   stream: ReadableStream<Uint8Array>,
   timeoutMs: number,