Squashed 'third_party/pi/' content from commit d981de122

git-subtree-dir: third_party/pi
git-subtree-split: d981de1229ef899957bbe968bc8dcda02a21f477

packages/ai/test/cloudflare-ai-binding.test.ts

@@ -0,0 +1,110 @@
+import { describe, expect, it } from "vitest";
+import {
+	type AiBinding,
+	CLOUDFLARE_GATEWAY_BINDING_AUTH_SENTINEL,
+	createAiBindingFetch,
+} from "../src/api/cloudflare-ai-binding.ts";
+import { streamSimple as streamOpenAICompletions } from "../src/api/openai-completions.ts";
+import type { Model } from "../src/types.ts";
+
+const BINDING_PREFIX = "https://workers-binding.ai/ai-gateway/gateways/my-gateway";
+
+function fakeBinding(response?: Response) {
+	const requests: Request[] = [];
+	const binding: AiBinding = {
+		aiGatewayLogId: null,
+		fetch: (input: Request | string | URL, init?: RequestInit) => {
+			requests.push(input instanceof Request ? input : new Request(input, init));
+			return Promise.resolve(response ?? new Response("{}"));
+		},
+	};
+	return { binding, requests };
+}
+
+describe("createAiBindingFetch", () => {
+	it("passes requests to the binding untouched", async () => {
+		const stream = new ReadableStream<Uint8Array>({
+			start(controller) {
+				controller.enqueue(new TextEncoder().encode("data: {}\n\n"));
+				controller.close();
+			},
+		});
+		const bindingResponse = new Response(stream, {
+			headers: { "content-type": "text/event-stream", "cf-aig-log-id": "log-1" },
+		});
+		const { binding, requests } = fakeBinding(bindingResponse);
+		// No cast at the call site: an `Ai` binding is accepted as-is, the way `env.AI` is typed.
+		const fetchFn = createAiBindingFetch(binding);
+		const body = JSON.stringify({ model: "claude", messages: [{ role: "user", content: "hi" }] });
+
+		const response = await fetchFn(`${BINDING_PREFIX}/anthropic/v1/messages?beta=true`, {
+			method: "POST",
+			headers: {
+				"content-type": "application/json",
+				"cf-aig-authorization": `Bearer ${CLOUDFLARE_GATEWAY_BINDING_AUTH_SENTINEL}`,
+				"anthropic-version": "2023-06-01",
+			},
+			body,
+		});
+
+		expect(requests[0].url).toBe(`${BINDING_PREFIX}/anthropic/v1/messages?beta=true`);
+		expect(requests[0].method).toBe("POST");
+		expect(Object.fromEntries(requests[0].headers)).toEqual({
+			"content-type": "application/json",
+			// The gateway recognizes and strips the sentinel itself; nothing here touches headers.
+			"cf-aig-authorization": `Bearer ${CLOUDFLARE_GATEWAY_BINDING_AUTH_SENTINEL}`,
+			"anthropic-version": "2023-06-01",
+		});
+		expect(await requests[0].text()).toBe(body);
+		expect(response).toBe(bindingResponse);
+		expect(await response.text()).toBe("data: {}\n\n");
+	});
+
+	it("rejects a binding with no fetch() at construction, not on first request", () => {
+		// A well-typed binding on a runtime that predates `Ai#fetch`: `fetch` is optional on the
+		// type, so the check has to happen at runtime — early, with a message that names the cause.
+		expect(() => createAiBindingFetch({ aiGatewayLogId: null })).toThrow("does not expose fetch()");
+	});
+
+	it("keeps SDK placeholder auth off the wire when paired with null auth headers", async () => {
+		// The full header contract from the module docs, end to end through a real API impl: the
+		// sentinel satisfies pi's request-auth check, and the explicit nulls make the OpenAI SDK
+		// delete its own `Authorization: Bearer unused` placeholder before dispatch.
+		const { binding, requests } = fakeBinding(
+			Response.json({ error: { type: "bad_request", message: "stubbed" } }, { status: 400 }),
+		);
+		const model: Model<"openai-completions"> = {
+			id: "test-model",
+			name: "Test Model",
+			api: "openai-completions",
+			provider: "openai",
+			baseUrl: `${BINDING_PREFIX}/openai`,
+			reasoning: false,
+			input: ["text"],
+			cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
+			contextWindow: 10_000,
+			maxTokens: 1_000,
+		};
+
+		const result = await streamOpenAICompletions(
+			model,
+			{ messages: [{ role: "user", content: "hello", timestamp: 1 }] },
+			{
+				headers: {
+					"cf-aig-authorization": `Bearer ${CLOUDFLARE_GATEWAY_BINDING_AUTH_SENTINEL}`,
+					Authorization: null,
+					"x-api-key": null,
+				},
+				fetch: createAiBindingFetch(binding),
+				maxRetries: 0,
+			},
+		).result();
+
+		expect(result.stopReason).toBe("error");
+		expect(requests).toHaveLength(1);
+		expect(requests[0].url).toBe(`${BINDING_PREFIX}/openai/chat/completions`);
+		const headerNames = Object.keys(Object.fromEntries(requests[0].headers));
+		expect(headerNames).not.toContain("authorization");
+		expect(headerNames).not.toContain("x-api-key");
+	});
+});