fix(openai): preserve reasoning_content for DeepSeek thinking mode

src/community/openai/__tests__/utils.test.ts

@@ -0,0 +1,58 @@
+import { describe, expect, test } from "bun:test";
+
+import type { Message } from "@/foundation";
+
+import { convertToOpenAIMessages } from "../utils";
+
+describe("convertToOpenAIMessages", () => {
+  test("preserves thinking content as reasoning_content", () => {
+    const messages: Message[] = [
+      { role: "user", content: [{ type: "text", text: "hello" }] },
+      {
+        role: "assistant",
+        content: [
+          { type: "thinking", thinking: "let me reason about this" },
+          { type: "text", text: "hi there" },
+        ],
+      },
+      { role: "user", content: [{ type: "text", text: "follow up" }] },
+    ];
+
+    const result = convertToOpenAIMessages(messages);
+    const assistantMsg = result[1] as unknown as Record<string, unknown>;
+
+    expect(assistantMsg.reasoning_content).toBe("let me reason about this");
+    expect(assistantMsg.content).toEqual([{ type: "text", text: "hi there" }]);
+  });
+
+  test("handles thinking-only assistant message (no text)", () => {
+    const messages: Message[] = [
+      { role: "user", content: [{ type: "text", text: "think about this" }] },
+      {
+        role: "assistant",
+        content: [{ type: "thinking", thinking: "deep thoughts" }],
+      },
+    ];
+
+    const result = convertToOpenAIMessages(messages);
+    const assistantMsg = result[1] as unknown as Record<string, unknown>;
+
+    expect(assistantMsg.reasoning_content).toBe("deep thoughts");
+  });
+
+  test("handles assistant message without thinking content", () => {
+    const messages: Message[] = [
+      { role: "user", content: [{ type: "text", text: "hello" }] },
+      {
+        role: "assistant",
+        content: [{ type: "text", text: "hi" }],
+      },
+    ];
+
+    const result = convertToOpenAIMessages(messages);
+    const assistantMsg = result[1] as unknown as Record<string, unknown>;
+
+    expect(assistantMsg.reasoning_content).toBeUndefined();
+    expect(assistantMsg.content).toEqual([{ type: "text", text: "hi" }]);
+  });
+});

src/community/openai/utils.ts

@@ -25,7 +25,7 @@ export function convertToOpenAIMessages(messages: Message[]): ChatCompletionMess
       };
       for (const content of message.content) {
         if (content.type === "thinking") {
-          continue;
+          (assistantMessage as unknown as Record<string, unknown>).reasoning_content = content.thinking;
         } else if (content.type === "tool_use") {
           if (!assistantMessage.tool_calls) {
             assistantMessage.tool_calls = [];