import {
type AssistantMessage,
type FauxProviderRegistration,
fauxAssistantMessage,
fauxText,
fauxThinking,
fauxToolCall,
type Model,
registerFauxProvider,
type ToolResultMessage,
type UserMessage,
} from "@earendil-works/pi-ai";
import { afterEach, describe, expect, it } from "vitest";
import { Agent, type AgentEvent } from "../src/index.js";
import { calculateTool } from "./utils/calculate.js";
const registrations: FauxProviderRegistration[] = [];
function createFauxRegistration(options: Parameters<typeof registerFauxProvider>[0] = {}): FauxProviderRegistration {
const registration = registerFauxProvider(options);
registrations.push(registration);
return registration;
}
function getTextContent(message: AssistantMessage | ToolResultMessage): string {
return message.content
.filter((block) => block.type === "text")
.map((block) => block.text)
.join("\n");
}
afterEach(() => {
while (registrations.length > 0) {
registrations.pop()?.unregister();
}
});
async function basicPrompt(model: Model<string>) {
const agent = new Agent({
initialState: {
systemPrompt: "You are a helpful assistant. Keep your responses concise.",
model,
thinkingLevel: "off",
tools: [],
},
});
await agent.prompt("What is 2+2? Answer with just the number.");
expect(agent.state.isStreaming).toBe(false);
expect(agent.state.messages.length).toBe(2);
expect(agent.state.messages[0].role).toBe("user");
expect(agent.state.messages[1].role).toBe("assistant");
const assistantMessage = agent.state.messages[1];
if (assistantMessage.role !== "assistant") throw new Error("Expected assistant message");
expect(getTextContent(assistantMessage)).toContain("4");
}
async function toolExecution(model: Model<string>) {
const agent = new Agent({
initialState: {
systemPrompt: "You are a helpful assistant. Always use the calculator tool for math.",
model,
thinkingLevel: "off",
tools: [calculateTool],
},
});
const pendingToolCallsDuringEvents: Array<{ type: AgentEvent["type"]; ids: string[] }> = [];
agent.subscribe((event) => {
if (event.type === "tool_execution_start" || event.type === "tool_execution_end") {
pendingToolCallsDuringEvents.push({
type: event.type,
ids: [...agent.state.pendingToolCalls],
});
}
});
await agent.prompt("Calculate 123 * 456 using the calculator tool.");
expect(agent.state.isStreaming).toBe(false);
expect(agent.state.messages.length).toBeGreaterThanOrEqual(4);
const toolResultMsg = agent.state.messages.find((message) => message.role === "toolResult");
expect(toolResultMsg).toBeDefined();
if (toolResultMsg?.role !== "toolResult") throw new Error("Expected tool result message");
expect(getTextContent(toolResultMsg)).toContain("123 * 456 = 56088");
const finalMessage = agent.state.messages[agent.state.messages.length - 1];
if (finalMessage.role !== "assistant") throw new Error("Expected final assistant message");
expect(getTextContent(finalMessage)).toContain("56088");
expect(agent.state.pendingToolCalls.size).toBe(0);
expect(pendingToolCallsDuringEvents).toEqual([
{ type: "tool_execution_start", ids: ["calc-1"] },
{ type: "tool_execution_end", ids: [] },
]);
}
async function abortExecution(model: Model<string>) {
const agent = new Agent({
initialState: {
systemPrompt: "You are a helpful assistant.",
model,
thinkingLevel: "off",
tools: [],
},
});
const promptPromise = agent.prompt("Count slowly from 1 to 20.");
setTimeout(() => {
agent.abort();
}, 30);
await promptPromise;
expect(agent.state.isStreaming).toBe(false);
expect(agent.state.messages.length).toBeGreaterThanOrEqual(2);
const lastMessage = agent.state.messages[agent.state.messages.length - 1];
if (lastMessage.role !== "assistant") throw new Error("Expected assistant message");
expect(lastMessage.stopReason).toBe("aborted");
expect(lastMessage.errorMessage).toBeDefined();
expect(agent.state.errorMessage).toBe(lastMessage.errorMessage);
}
async function stateUpdates(model: Model<string>) {
const agent = new Agent({
initialState: {
systemPrompt: "You are a helpful assistant.",
model,
thinkingLevel: "off",
tools: [],
},
});
const events: AgentEvent["type"][] = [];
agent.subscribe((event) => {
events.push(event.type);
});
await agent.prompt("Count from 1 to 5.");
expect(events).toContain("agent_start");
expect(events).toContain("turn_start");
expect(events).toContain("message_start");
expect(events).toContain("message_update");
expect(events).toContain("message_end");
expect(events).toContain("turn_end");
expect(events).toContain("agent_end");
expect(events.indexOf("agent_start")).toBeLessThan(events.indexOf("message_start"));
expect(events.indexOf("message_start")).toBeLessThan(events.indexOf("message_end"));
expect(events.indexOf("message_end")).toBeLessThan(events.lastIndexOf("agent_end"));
expect(agent.state.isStreaming).toBe(false);
expect(agent.state.messages.length).toBe(2);
}
async function multiTurnConversation(model: Model<string>) {
const agent = new Agent({
initialState: {
systemPrompt: "You are a helpful assistant.",
model,
thinkingLevel: "off",
tools: [],
},
});
await agent.prompt("My name is Alice.");
expect(agent.state.messages.length).toBe(2);
await agent.prompt("What is my name?");
expect(agent.state.messages.length).toBe(4);
const lastMessage = agent.state.messages[3];
if (lastMessage.role !== "assistant") throw new Error("Expected assistant message");
expect(getTextContent(lastMessage).toLowerCase()).toContain("alice");
}
describe("Agent integration with faux provider", () => {
it("handles a basic text prompt", async () => {
const faux = createFauxRegistration();
faux.setResponses([fauxAssistantMessage("4")]);
await basicPrompt(faux.getModel());
});
it("executes tools and tracks pending tool calls", async () => {
const faux = createFauxRegistration();
faux.setResponses([
fauxAssistantMessage(
[
fauxText("Let me calculate that."),
fauxToolCall("calculate", { expression: "123 * 456" }, { id: "calc-1" }),
],
{ stopReason: "toolUse" },
),
fauxAssistantMessage("The result is 56088."),
]);
await toolExecution(faux.getModel());
});
it("handles abort during streaming", async () => {
const faux = createFauxRegistration({
tokensPerSecond: 20,
tokenSize: { min: 2, max: 2 },
});
faux.setResponses([
fauxAssistantMessage(
"one two three four five six seven eight nine ten eleven twelve thirteen fourteen fifteen",
),
]);
await abortExecution(faux.getModel());
});
it("emits lifecycle updates while streaming", async () => {
const faux = createFauxRegistration({ tokenSize: { min: 1, max: 1 } });
faux.setResponses([fauxAssistantMessage("1 2 3 4 5")]);
await stateUpdates(faux.getModel());
});
it("maintains context across multiple turns", async () => {
const faux = createFauxRegistration();
faux.setResponses([
fauxAssistantMessage("Nice to meet you, Alice."),
(context) => {
const hasAlice = context.messages.some((message) => {
if (message.role !== "user") return false;
if (typeof message.content === "string") return message.content.includes("Alice");
return message.content.some((block) => block.type === "text" && block.text.includes("Alice"));
});
return fauxAssistantMessage(hasAlice ? "Your name is Alice." : "I do not know your name.");
},
]);
await multiTurnConversation(faux.getModel());
});
it("preserves thinking content blocks", async () => {
const faux = createFauxRegistration({ models: [{ id: "faux-reasoning", reasoning: true }] });
faux.setResponses([fauxAssistantMessage([fauxThinking("step by step"), fauxText("4")])]);
const agent = new Agent({
initialState: {
systemPrompt: "You are a helpful assistant.",
model: faux.getModel(),
thinkingLevel: "low",
tools: [],
},
});
await agent.prompt("What is 2+2?");
const assistantMessage = agent.state.messages[1];
if (assistantMessage?.role !== "assistant") throw new Error("Expected assistant message");
expect(assistantMessage.content).toEqual([
{ type: "thinking", thinking: "step by step" },
{ type: "text", text: "4" },
]);
});
});
describe("Agent.continue() with faux provider", () => {
describe("validation", () => {
it("throws when no messages in context", async () => {
const faux = createFauxRegistration();
const agent = new Agent({
initialState: {
systemPrompt: "Test",
model: faux.getModel(),
},
});
await expect(agent.continue()).rejects.toMatchObject({
code: "nothing-to-continue",
message: "No messages to continue from",
});
});
it("throws when last message is assistant", async () => {
const faux = createFauxRegistration();
const model = faux.getModel();
const agent = new Agent({
initialState: {
systemPrompt: "Test",
model,
},
});
const assistantMessage: AssistantMessage = {
role: "assistant",
content: [{ type: "text", text: "Hello" }],
api: model.api,
provider: model.provider,
model: model.id,
usage: {
input: 0,
output: 0,
cacheRead: 0,
cacheWrite: 0,
totalTokens: 0,
cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0, total: 0 },
},
stopReason: "stop",
timestamp: Date.now(),
};
agent.state.messages = [assistantMessage];
await expect(agent.continue()).rejects.toMatchObject({
code: "nothing-to-continue",
message: "Cannot continue from message role: assistant",
});
});
});
describe("continue from user message", () => {
it("continues and gets a response when last message is user", async () => {
const faux = createFauxRegistration();
faux.setResponses([fauxAssistantMessage("HELLO WORLD")]);
const agent = new Agent({
initialState: {
systemPrompt: "You are a helpful assistant. Follow instructions exactly.",
model: faux.getModel(),
thinkingLevel: "off",
tools: [],
},
});
const userMessage: UserMessage = {
role: "user",
content: [{ type: "text", text: "Say exactly: HELLO WORLD" }],
timestamp: Date.now(),
};
agent.state.messages = [userMessage];
await agent.continue();
expect(agent.state.isStreaming).toBe(false);
expect(agent.state.messages.length).toBe(2);
expect(agent.state.messages[0].role).toBe("user");
expect(agent.state.messages[1].role).toBe("assistant");
const assistantMsg = agent.state.messages[1];
if (assistantMsg.role !== "assistant") throw new Error("Expected assistant message");
expect(getTextContent(assistantMsg).toUpperCase()).toContain("HELLO WORLD");
});
});
describe("continue from tool result", () => {
it("continues and processes tool results", async () => {
const faux = createFauxRegistration();
const model = faux.getModel();
faux.setResponses([fauxAssistantMessage("The answer is 8.")]);
const agent = new Agent({
initialState: {
systemPrompt:
"You are a helpful assistant. After getting a calculation result, state the answer clearly.",
model,
thinkingLevel: "off",
tools: [calculateTool],
},
});
const userMessage: UserMessage = {
role: "user",
content: [{ type: "text", text: "What is 5 + 3?" }],
timestamp: Date.now(),
};
const assistantMessage: AssistantMessage = {
role: "assistant",
content: [
{ type: "text", text: "Let me calculate that." },
{ type: "toolCall", id: "calc-1", name: "calculate", arguments: { expression: "5 + 3" } },
],
api: model.api,
provider: model.provider,
model: model.id,
usage: {
input: 0,
output: 0,
cacheRead: 0,
cacheWrite: 0,
totalTokens: 0,
cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0, total: 0 },
},
stopReason: "toolUse",
timestamp: Date.now(),
};
const toolResult: ToolResultMessage = {
role: "toolResult",
toolCallId: "calc-1",
toolName: "calculate",
content: [{ type: "text", text: "5 + 3 = 8" }],
isError: false,
timestamp: Date.now(),
};
agent.state.messages = [userMessage, assistantMessage, toolResult];
await agent.continue();
expect(agent.state.isStreaming).toBe(false);
expect(agent.state.messages.length).toBeGreaterThanOrEqual(4);
const lastMessage = agent.state.messages[agent.state.messages.length - 1];
expect(lastMessage.role).toBe("assistant");
if (lastMessage.role !== "assistant") throw new Error("Expected assistant message");
expect(getTextContent(lastMessage)).toContain("8");
});
});
});