Revert "fix(openai-chat): complete streams that end after output without terminal"

src/adapters/openai-chat.ts

@@ -660,7 +660,6 @@ export function createOpenAIChatAdapter(provider: OcxProviderConfig): ProviderAd
       const pendingToolCalls: PendingToolCall[] = [];
       let toolCallSeq = 0;
       const flushToolCalls = function* (): Generator<AdapterEvent> {
-        if (pendingToolCalls.length > 0) sawOutput = true;
         for (const call of pendingToolCalls) {
           if (!call.id) call.id = `call_${++toolCallSeq}`;
           yield { type: "tool_call_start", id: call.id, name: call.name };
@@ -675,7 +674,6 @@ export function createOpenAIChatAdapter(provider: OcxProviderConfig): ProviderAd
       // explicit `[DONE]` sentinel OR a chunk carrying a non-null `finish_reason` (some
       // OpenAI-compatible providers omit `[DONE]` but do send finish_reason).
       let finishReason: string | undefined;
-      let sawOutput = false;
 
       // Single per-line handler shared by the streaming loop and the EOF residual-frame flush, so
       // a final frame is parsed identically wherever it lands (no duplicated, drift-prone parsing).
@@ -742,11 +740,9 @@ export function createOpenAIChatAdapter(provider: OcxProviderConfig): ProviderAd
         const delta = choices[0].delta;
         if (delta) {
           if (typeof delta.reasoning_content === "string" && delta.reasoning_content.length > 0) {
-            sawOutput = true;
             yield { type: "reasoning_raw_delta", text: delta.reasoning_content };
           }
           if (typeof delta.content === "string" && delta.content.length > 0) {
-            sawOutput = true;
             yield { type: "text_delta", text: delta.content };
           }
 
@@ -804,23 +800,13 @@ export function createOpenAIChatAdapter(provider: OcxProviderConfig): ProviderAd
         if (buffer.length > 0) {
           if ((yield* handleDataLine(buffer)) === "terminate") return;
         }
-        const hadPendingToolCallsAtEof = pendingToolCalls.length > 0;
         yield* flushToolCalls();
         // Reader EOF. A graceful close shows at least one terminal signal: `[DONE]` (returns above),
         // a non-null finish_reason (sawFinish), or a trailing usage chunk (providers emit usage only
         // at end-of-generation). If NONE of those were seen, the stream was cut mid-flight — fail
         // closed so the bridge emits a classified response.failed rather than a silent truncation.
         const sawFinish = finishReason !== undefined;
-        if (!sawFinish && pendingUsage === undefined && hadPendingToolCallsAtEof) {
-          debugProviderDiagnostic("openai-chat", "stream-truncated", {
-            finishReason: finishReason ?? null,
-            hadUsage: false,
-            pendingToolCalls: true,
-          });
-          yield { type: "error", message: "upstream stream ended without a terminal signal ([DONE] or finish_reason) - possible truncation" };
-          return;
-        }
-        if (!sawFinish && pendingUsage === undefined && !sawOutput) {
+        if (!sawFinish && pendingUsage === undefined) {
           debugProviderDiagnostic("openai-chat", "stream-truncated", {
             finishReason: finishReason ?? null,
             hadUsage: false,

tests/openai-chat-eof.test.ts

@@ -12,18 +12,11 @@ async function collect(gen: AsyncGenerator<AdapterEvent>): Promise<AdapterEvent[
 }
 
 describe("openai-chat stream EOF fail-closed", () => {
-  test("truncated stream (no [DONE], no finish_reason) yields done when content was emitted", async () => {
+  test("truncated stream (no [DONE], no finish_reason) yields a terminal error, not a clean done", async () => {
     const response = new Response('data: {"choices":[{"delta":{"content":"par"}}]}\n\n');
     const events = await collect(createOpenAIChatAdapter(provider).parseStream(response));
     const last = events[events.length - 1];
-    expect(last.type).toBe("done");
-    expect(events.some(e => e.type === "error")).toBe(false);
-  });
-
-  test("empty EOF without content still errors", async () => {
-    const response = new Response("");
-    const events = await collect(createOpenAIChatAdapter(provider).parseStream(response));
-    expect(events.at(-1)?.type).toBe("error");
+    expect(last.type).toBe("error");
     expect(events.some(e => e.type === "done")).toBe(false);
   });
 
@@ -135,11 +128,11 @@ describe("openai-chat stream EOF fail-closed", () => {
     expect(events.some(e => e.type === "error")).toBe(false);
   });
 
-  test("genuinely truncated stream WITHOUT a trailing newline completes when content was emitted", async () => {
-    // Mid-content frame, no terminator, no newline — content was yielded, so accept done.
+  test("genuinely truncated stream WITHOUT a trailing newline still fails closed", async () => {
+    // Mid-content frame, no terminator, no newline — must remain a terminal error.
     const response = new Response('data: {"choices":[{"delta":{"content":"par"}}]}');
     const events = await collect(createOpenAIChatAdapter(provider).parseStream(response));
-    expect(events.at(-1)?.type).toBe("done");
-    expect(events.some(e => e.type === "error")).toBe(false);
+    expect(events.at(-1)?.type).toBe("error");
+    expect(events.some(e => e.type === "done")).toBe(false);
   });
 });