fix: align stream cancellation with committed output

2026-07-21 13:11:52 +08:00
parent 697aac2325
commit 2eb978064c
2 changed files with 114 additions and 7 deletions
@@ -158,21 +158,22 @@ export function streamTextResponse(
  let pending = "";
  let settled = false;
  let emitted = false;
-  let firstOutputSettled = false;
+  let firstOutputSettlementStarted = false;

-  async function settleFirstOutput(value: string) {
-    if (!/\S/.test(value) || firstOutputSettled) return;
-    firstOutputSettled = true;
-    await options.onFirstOutput?.();
+  function startFirstOutputSettlement(value: string) {
+    if (!/\S/.test(value) || firstOutputSettlementStarted) return undefined;
+    firstOutputSettlementStarted = true;
+    return options.onFirstOutput?.();
  }

  async function enqueueOutput(
    controller: ReadableStreamDefaultController<Uint8Array>,
    value: string,
  ) {
-    await settleFirstOutput(value);
+    const firstOutputSettlement = startFirstOutputSettlement(value);
    controller.enqueue(encoder.encode(value));
    if (/\S/.test(value)) emitted = true;
+    await firstOutputSettlement;
  }

  const body = new ReadableStream<Uint8Array>({
@@ -187,6 +188,7 @@ export function streamTextResponse(
            if (finalText) {
              await enqueueOutput(controller, finalText);
            }
+            if (settled) return;
            settled = true;
            if (!emitted) {
              const error = new Error("empty_stream");