pi-mono/packages/ai/test/openai-decisions.test.ts

import { describe, expect, it, vi } from "vitest";
import { classify } from "../src/api/openai-decisions.ts";
import type { ClassifierContext, ClassifierModel, ImageContent } from "../src/types.ts";

const model: ClassifierModel<"openai-decisions"> = {
	type: "classifier",
	id: "gpt-6-luna",
	name: "GPT-6 Luna",
	api: "openai-decisions",
	provider: "openai",
	baseUrl: "https://api.openai.com/v1",
	input: ["text", "image"],
	cost: {
		input: 0.1,
		output: 0,
		cacheRead: 0,
		cacheWrite: 0,
		tiers: [{ inputTokensAbove: 272000, input: 0.2, output: 0, cacheRead: 0, cacheWrite: 0 }],
	},
	contextWindow: 922000,
};

const context: ClassifierContext = {
	state: { text: "The deployment succeeded, thank you." },
	questions: {
		category: {
			type: "choice",
			instructions: "Classify the message",
			criteria: { success: "Successful", failure: "" },
		},
		satisfaction: {
			type: "score",
			instructions: "Score satisfaction",
			criteria: ["low", "neutral", "high"],
		},
		approved: {
			type: "bool",
			instructions: "Does the user approve?",
			criteria: { true: "Approval", false: "No approval" },
		},
	},
};

/** Response shape from the API reference and live `gpt-6-luna` requests. */
const wireAnswers = [
	{
		type: "choice",
		name: "category",
		choice: "success",
		probabilities: [
			{ value: "success", probability: 0.9 },
			{ value: "failure", probability: 0.1 },
		],
		confidence: 0.8,
	},
	{
		type: "score",
		name: "satisfaction",
		score: 1.8,
		probabilities: [
			{ value: 0, label: "low", probability: 0.05 },
			{ value: 1, label: "neutral", probability: 0.1 },
			{ value: 2, label: "high", probability: 0.85 },
		],
		confidence: 0.7,
	},
	{ type: "predicate", name: "approved", probability: 0.95 },
];

const wireUsage = {
	input_tokens: 164,
	input_tokens_details: { cached_tokens: 0, cache_write_tokens: 0 },
	output_tokens: 0,
	output_tokens_details: { reasoning_tokens: 0 },
	total_tokens: 164,
};

const image: ImageContent = { type: "image", data: "aW1hZ2U=", mimeType: "image/png" };

describe("OpenAI Decisions", () => {
	it("maps questions to Decisions types and answers back by name", async () => {
		const fetch = vi.fn(async (_input: string | URL | Request, _init?: RequestInit) =>
			// Answers out of question order: they are matched by name.
			Response.json({ model: "gpt-6-luna", answers: [...wireAnswers].reverse(), usage: wireUsage }),
		);

		const result = await classify(model, context, { apiKey: "secret", fetch, temperature: 1.5 });

		expect(fetch).toHaveBeenCalledOnce();
		const [url, init] = fetch.mock.calls[0]!;
		expect(String(url)).toBe("https://api.openai.com/v1/decisions");
		expect(new Headers(init?.headers).get("authorization")).toBe("Bearer secret");
		expect(JSON.parse(String(init?.body))).toEqual({
			model: "gpt-6-luna",
			input: JSON.stringify(context.state),
			questions: [
				{
					type: "choice",
					name: "category",
					instructions: "Classify the message",
					// Empty descriptions are omitted.
					choices: [{ value: "success", description: "Successful" }, { value: "failure" }],
				},
				{
					type: "score",
					name: "satisfaction",
					instructions: "Score satisfaction",
					levels: [{ label: "low" }, { label: "neutral" }, { label: "high" }],
				},
				{
					type: "predicate",
					name: "approved",
					instructions: "Does the user approve?\n\nTrue means: Approval\nFalse means: No approval",
				},
			],
		});
		expect(result.stopReason).toBe("stop");
		expect(result.answers).toEqual({
			category: {
				type: "choice",
				choice: "success",
				probabilities: { success: 0.9, failure: 0.1 },
				confidence: 0.8,
			},
			satisfaction: { type: "score", score: 1.8, confidence: 0.7 },
			approved: { type: "bool", probability: 0.95 },
		});
		expect(result.usage).toMatchObject({ input: 164, output: 0, cacheRead: 0, totalTokens: 164 });
		expect(result.usage?.cost.total).toBeCloseTo(0.0000164, 12);
	});

	it("prices long-context requests at the long-context input rate", async () => {
		const result = await classify(model, context, {
			apiKey: "secret",
			fetch: async () => Response.json({ answers: wireAnswers, usage: { input_tokens: 300000, output_tokens: 0 } }),
		});

		expect(result.usage?.cost.total).toBeCloseTo(0.06, 12);
	});

	it("sends images after the state in one user message", async () => {
		const fetch = vi.fn(async (_input: string | URL | Request, _init?: RequestInit) =>
			Response.json({ answers: wireAnswers }),
		);

		const result = await classify(
			model,
			{ ...context, images: [image, { ...image, mimeType: "image/jpeg" }] },
			{
				apiKey: "secret",
				fetch,
			},
		);

		expect(result.stopReason).toBe("stop");
		expect(JSON.parse(String(fetch.mock.calls[0]?.[1]?.body)).input).toEqual([
			{
				role: "user",
				content: [
					{ type: "input_text", text: JSON.stringify(context.state) },
					{ type: "input_image", image_url: "data:image/png;base64,aW1hZ2U=" },
					{ type: "input_image", image_url: "data:image/jpeg;base64,aW1hZ2U=" },
				],
			},
		]);
	});

	it("rejects more than 128 images before sending", async () => {
		const fetch = vi.fn(async () => Response.json({ answers: wireAnswers }));

		const result = await classify(
			model,
			{ ...context, images: Array.from({ length: 129 }, () => image) },
			{
				apiKey: "secret",
				fetch,
			},
		);

		expect(fetch).not.toHaveBeenCalled();
		expect(result.stopReason).toBe("error");
		expect(result.errorMessage).toContain("at most 128 images, got 129");
	});

	it("fails the result when a question is refused and keeps the billed usage", async () => {
		const result = await classify(model, context, {
			apiKey: "secret",
			fetch: async () =>
				Response.json({
					answers: [wireAnswers[0], wireAnswers[1], { type: "refusal", name: "approved" }],
					usage: wireUsage,
				}),
		});

		expect(result.stopReason).toBe("error");
		expect(result.answers).toEqual({});
		expect(result.errorMessage).toBe("OpenAI Decisions refused to answer approved");
		expect(result.usage).toMatchObject({ input: 164 });
	});

	it("returns missing and mistyped answers as classifier errors", async () => {
		const missing = await classify(model, context, {
			apiKey: "secret",
			fetch: async () => Response.json({ answers: wireAnswers.slice(0, 2) }),
		});
		const mistyped = await classify(model, context, {
			apiKey: "secret",
			fetch: async () =>
				Response.json({ answers: [wireAnswers[0], wireAnswers[1], { type: "score", name: "approved" }] }),
		});

		expect(missing.stopReason).toBe("error");
		expect(missing.errorMessage).toContain("did not return an answer for approved");
		expect(mistyped.stopReason).toBe("error");
		expect(mistyped.errorMessage).toContain("did not return a predicate answer for approved");
	});

	it("preserves prototype-sensitive question IDs in answers", async () => {
		const prototypeContext: ClassifierContext = {
			state: {},
			questions: JSON.parse(
				'{"__proto__":{"type":"bool","instructions":"Is this true?","criteria":{"true":"Yes","false":"No"}}}',
			),
		};
		const result = await classify(model, prototypeContext, {
			apiKey: "secret",
			fetch: async () => Response.json({ answers: [{ type: "predicate", name: "__proto__", probability: 0.75 }] }),
		});

		expect(result.stopReason).toBe("stop");
		expect(Object.hasOwn(result.answers, "__proto__")).toBe(true);
		expect(result.answers.__proto__).toEqual({ type: "bool", probability: 0.75 });
	});

	it("does not retry gateway timeouts and explains them instead of returning the HTML page", async () => {
		const fetch = vi.fn(
			async () =>
				new Response("<!DOCTYPE html><html>Gateway time-out</html>", {
					status: 504,
					headers: { "retry-after-ms": "0" },
				}),
		);
		// Default retries: the same input would time out again.
		const result = await classify(model, context, { apiKey: "secret", fetch });

		expect(fetch).toHaveBeenCalledOnce();
		expect(result.stopReason).toBe("error");
		expect(result.errorMessage).toContain("OpenAI Decisions error (504): the request timed out at the gateway");
		expect(result.errorMessage).not.toContain("<html>");
	});

	it("still retries other server errors", async () => {
		let attempt = 0;
		const result = await classify(model, context, {
			apiKey: "secret",
			fetch: async () =>
				++attempt === 1
					? new Response("busy", { status: 503, headers: { "retry-after-ms": "0" } })
					: Response.json({ answers: wireAnswers }),
		});

		expect(attempt).toBe(2);
		expect(result.stopReason).toBe("stop");
	});

	it("includes the API error body for other HTTP failures", async () => {
		const result = await classify(model, context, {
			apiKey: "secret",
			maxRetries: 0,
			fetch: async () =>
				Response.json(
					{ error: { message: "Decision input exceeds the token limit.", type: "invalid_request_error" } },
					{ status: 400 },
				),
		});

		expect(result.stopReason).toBe("error");
		expect(result.errorMessage).toContain("OpenAI Decisions error (400)");
		expect(result.errorMessage).toContain("Decision input exceeds the token limit.");
	});

	it("rejects models for other classifier APIs and missing API keys", async () => {
		const fetch = vi.fn(async () => Response.json({ answers: wireAnswers }));
		const otherApi = await classify({ ...model, api: "typesafe-system-one" }, context, { apiKey: "secret", fetch });
		const noKey = await classify(model, context, { fetch });

		expect(fetch).not.toHaveBeenCalled();
		expect(otherApi.errorMessage).toContain("Unsupported classifier API: typesafe-system-one");
		expect(noKey.errorMessage).toContain("No API key for provider: openai");
	});
});