import { beforeEach, describe, expect, it, vi } from "vitest";
import { complete } from "../src/stream.js";
import type { Model } from "../src/types.js";
const mockState = vi.hoisted(() => ({
chunks: [] as unknown[],
}));
vi.mock("openai", () => {
class FakeOpenAI {
chat = {
completions: {
create: () => {
const chunks = mockState.chunks;
const stream = {
async *[Symbol.asyncIterator]() {
for (const chunk of chunks) yield chunk;
},
};
const promise = Promise.resolve(stream) as Promise<typeof stream> & {
withResponse: () => Promise<{
data: typeof stream;
response: { status: number; headers: Headers };
}>;
};
promise.withResponse = async () => ({
data: stream,
response: { status: 200, headers: new Headers() },
});
return promise;
},
},
};
}
return { default: FakeOpenAI };
});
function openRouterAuto(): Model<"openai-completions"> {
return {
id: "openrouter/auto",
name: "OpenRouter Auto",
api: "openai-completions",
provider: "openrouter",
baseUrl: "https://openrouter.ai/api/v1",
reasoning: false,
input: ["text"],
cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
contextWindow: 200_000,
maxTokens: 8192,
};
}
describe("openai-completions responseModel", () => {
beforeEach(() => {
mockState.chunks = [];
});
it("surfaces routed chunk.model on responseModel without changing model", async () => {
mockState.chunks = [
{ id: "chatcmpl-1", model: "anthropic/claude-opus-4.7", choices: [{ index: 0, delta: { content: "hi" } }] },
{
id: "chatcmpl-1",
model: "anthropic/claude-opus-4.7",
choices: [{ index: 0, delta: {}, finish_reason: "stop" }],
usage: {
prompt_tokens: 10,
completion_tokens: 5,
prompt_tokens_details: { cached_tokens: 0 },
completion_tokens_details: { reasoning_tokens: 0 },
},
},
];
const message = await complete(
openRouterAuto(),
{ messages: [{ role: "user", content: "hi", timestamp: Date.now() }] },
{ apiKey: "test" },
);
expect(message.model).toBe("openrouter/auto");
expect(message.responseModel).toBe("anthropic/claude-opus-4.7");
expect(message.provider).toBe("openrouter");
expect(message.stopReason).toBe("stop");
});
it("leaves responseModel undefined when chunks echo the requested id", async () => {
mockState.chunks = [
{ id: "chatcmpl-2", model: "openrouter/auto", choices: [{ index: 0, delta: { content: "hi" } }] },
{
id: "chatcmpl-2",
model: "openrouter/auto",
choices: [{ index: 0, delta: {}, finish_reason: "stop" }],
usage: {
prompt_tokens: 1,
completion_tokens: 1,
prompt_tokens_details: { cached_tokens: 0 },
completion_tokens_details: { reasoning_tokens: 0 },
},
},
];
const message = await complete(
openRouterAuto(),
{ messages: [{ role: "user", content: "hi", timestamp: Date.now() }] },
{ apiKey: "test" },
);
expect(message.model).toBe("openrouter/auto");
expect(message.responseModel).toBeUndefined();
});
it("ignores empty or missing chunk.model", async () => {
mockState.chunks = [
{ id: "chatcmpl-3", choices: [{ index: 0, delta: { content: "hi" } }] },
{ id: "chatcmpl-3", model: "", choices: [{ index: 0, delta: { content: "!" } }] },
{
id: "chatcmpl-3",
choices: [{ index: 0, delta: {}, finish_reason: "stop" }],
usage: {
prompt_tokens: 1,
completion_tokens: 2,
prompt_tokens_details: { cached_tokens: 0 },
completion_tokens_details: { reasoning_tokens: 0 },
},
},
];
const message = await complete(
openRouterAuto(),
{ messages: [{ role: "user", content: "hi", timestamp: Date.now() }] },
{ apiKey: "test" },
);
expect(message.model).toBe("openrouter/auto");
expect(message.responseModel).toBeUndefined();
});
});