From 728e29a89876e72202610aa9f8ec8e715f5b2e9e Mon Sep 17 00:00:00 2001
From: Peter Steinberger <steipete@gmail.com>
Date: Thu, 23 Apr 2026 03:52:26 +0100
Subject: [PATCH] test(agents): cover openai-completions tool-call arg repair

---
 .../attempt.tool-call-argument-repair.test.ts | 107 +++++++++++++++++-
 1 file changed, 106 insertions(+), 1 deletion(-)

diff --git a/src/agents/pi-embedded-runner/run/attempt.tool-call-argument-repair.test.ts b/src/agents/pi-embedded-runner/run/attempt.tool-call-argument-repair.test.ts
index 5392c90d7d3..6f96b01f2a1 100644
--- a/src/agents/pi-embedded-runner/run/attempt.tool-call-argument-repair.test.ts
+++ b/src/agents/pi-embedded-runner/run/attempt.tool-call-argument-repair.test.ts
@@ -1,5 +1,51 @@
 import { describe, expect, it } from "vitest";
-import { shouldRepairMalformedToolCallArguments } from "./attempt.tool-call-argument-repair.js";
+import {
+  shouldRepairMalformedToolCallArguments,
+  wrapStreamFnRepairMalformedToolCallArguments,
+} from "./attempt.tool-call-argument-repair.js";
+
+type FakeWrappedStream = {
+  result: () => Promise<unknown>;
+  [Symbol.asyncIterator]: () => AsyncIterator<unknown>;
+};
+
+type FakeStreamFn = (
+  model: never,
+  context: never,
+  options: never,
+) => FakeWrappedStream | Promise<FakeWrappedStream>;
+
+function createFakeStream(params: {
+  events: unknown[];
+  resultMessage: unknown;
+}): FakeWrappedStream {
+  return {
+    async result() {
+      return params.resultMessage;
+    },
+    [Symbol.asyncIterator]() {
+      return (async function* () {
+        for (const event of params.events) {
+          yield event;
+        }
+      })();
+    },
+  };
+}
+
+async function invokeProviderStream(params: {
+  provider: string;
+  modelApi: string;
+  baseFn: FakeStreamFn;
+}): Promise<FakeWrappedStream> {
+  const streamFn = shouldRepairMalformedToolCallArguments({
+    provider: params.provider,
+    modelApi: params.modelApi,
+  })
+    ? (wrapStreamFnRepairMalformedToolCallArguments(params.baseFn as never) as FakeStreamFn)
+    : params.baseFn;
+  return await Promise.resolve(streamFn({} as never, {} as never, {} as never));
+}
 
 describe("shouldRepairMalformedToolCallArguments", () => {
   it("keeps the repair enabled for kimi providers on anthropic-messages", () => {
@@ -38,3 +84,62 @@ describe("shouldRepairMalformedToolCallArguments", () => {
     ).toBe(false);
   });
 });
+
+describe("openai-completions malformed tool-call argument repair", () => {
+  it("repairs fragmented OpenAI-compatible function-call args before tool execution", async () => {
+    const partialToolCall = { type: "functionCall", name: "read", arguments: {} };
+    const streamedToolCall = { type: "functionCall", name: "read", arguments: {} };
+    const endMessageToolCall = { type: "functionCall", name: "read", arguments: {} };
+    const finalToolCall = { type: "functionCall", name: "read", arguments: {} };
+    const partialMessage = { role: "assistant", content: [partialToolCall] };
+    const endMessage = { role: "assistant", content: [endMessageToolCall] };
+    const finalMessage = { role: "assistant", content: [finalToolCall] };
+
+    const stream = await invokeProviderStream({
+      provider: "sglang",
+      modelApi: "openai-completions",
+      baseFn: () =>
+        createFakeStream({
+          events: [
+            {
+              type: "toolcall_delta",
+              contentIndex: 0,
+              delta: ".functions.read:0 ",
+              partial: partialMessage,
+            },
+            {
+              type: "toolcall_delta",
+              contentIndex: 0,
+              delta: '{"path":"/tmp/report.txt"',
+              partial: partialMessage,
+            },
+            {
+              type: "toolcall_delta",
+              contentIndex: 0,
+              delta: "}x",
+              partial: partialMessage,
+            },
+            {
+              type: "toolcall_end",
+              contentIndex: 0,
+              toolCall: streamedToolCall,
+              partial: partialMessage,
+              message: endMessage,
+            },
+          ],
+          resultMessage: finalMessage,
+        }),
+    });
+
+    for await (const _item of stream) {
+      // drain
+    }
+    const result = await stream.result();
+
+    expect(partialToolCall.arguments).toEqual({ path: "/tmp/report.txt" });
+    expect(streamedToolCall.arguments).toEqual({ path: "/tmp/report.txt" });
+    expect(endMessageToolCall.arguments).toEqual({ path: "/tmp/report.txt" });
+    expect(finalToolCall.arguments).toEqual({ path: "/tmp/report.txt" });
+    expect(result).toBe(finalMessage);
+  });
+});