clanker-agent/packages/ai/test/google-gemini-cli-claude-thinking-header.test.ts

import { afterEach, describe, expect, it, vi } from "vitest";
import { streamGoogleGeminiCli } from "../src/providers/google-gemini-cli.js";
import type { Context, Model } from "../src/types.js";

const originalFetch = global.fetch;
const apiKey = JSON.stringify({ token: "token", projectId: "project" });

const createSseResponse = () => {
  const sse = `${[
    `data: ${JSON.stringify({
      response: {
        candidates: [
          {
            content: { role: "model", parts: [{ text: "Hello" }] },
            finishReason: "STOP",
          },
        ],
      },
    })}`,
  ].join("\n\n")}\n\n`;

  const encoder = new TextEncoder();
  const stream = new ReadableStream<Uint8Array>({
    start(controller) {
      controller.enqueue(encoder.encode(sse));
      controller.close();
    },
  });

  return new Response(stream, {
    status: 200,
    headers: { "content-type": "text/event-stream" },
  });
};

afterEach(() => {
  global.fetch = originalFetch;
  vi.restoreAllMocks();
});

describe("google-gemini-cli Claude thinking header", () => {
  const context: Context = {
    messages: [{ role: "user", content: "Say hello", timestamp: Date.now() }],
  };

  it("adds anthropic-beta for Claude thinking models", async () => {
    const fetchMock = vi.fn(
      async (_input: string | URL, init?: RequestInit) => {
        const headers = new Headers(init?.headers);
        expect(headers.get("anthropic-beta")).toBe(
          "interleaved-thinking-2025-05-14",
        );
        return createSseResponse();
      },
    );

    global.fetch = fetchMock as typeof fetch;

    const model: Model<"google-gemini-cli"> = {
      id: "claude-opus-4-5-thinking",
      name: "Claude Opus 4.5 Thinking",
      api: "google-gemini-cli",
      provider: "google-antigravity",
      baseUrl: "https://cloudcode-pa.googleapis.com",
      reasoning: true,
      input: ["text"],
      cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
      contextWindow: 128000,
      maxTokens: 8192,
    };

    const stream = streamGoogleGeminiCli(model, context, { apiKey });
    for await (const _event of stream) {
      // exhaust stream
    }
    await stream.result();
  });

  it("does not add anthropic-beta for Gemini models", async () => {
    const fetchMock = vi.fn(
      async (_input: string | URL, init?: RequestInit) => {
        const headers = new Headers(init?.headers);
        expect(headers.has("anthropic-beta")).toBe(false);
        return createSseResponse();
      },
    );

    global.fetch = fetchMock as typeof fetch;

    const model: Model<"google-gemini-cli"> = {
      id: "gemini-2.5-flash",
      name: "Gemini 2.5 Flash",
      api: "google-gemini-cli",
      provider: "google-gemini-cli",
      baseUrl: "https://cloudcode-pa.googleapis.com",
      reasoning: false,
      input: ["text"],
      cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
      contextWindow: 128000,
      maxTokens: 8192,
    };

    const stream = streamGoogleGeminiCli(model, context, { apiKey });
    for await (const _event of stream) {
      // exhaust stream
    }
    await stream.result();
  });
});