Event Generation for Testing

This guide shows how to use NDK's test utilities to generate various types of events for testing purposes.

Basic Event Generation

Use the EventGenerator to create different types of events:

import { EventGenerator } from "@nostr-dev-kit/ndk/test";
import { NDK } from "@nostr-dev-kit/ndk";

const ndk = new NDK();
EventGenerator.setNDK(ndk); // Required setup
const generator = new EventGenerator();

// Generate a text note (kind 1)
const textNote = await generator.textNote("Hello World");

// Generate metadata (kind 0)
const metadata = await generator.metadata({
    name: "Test User",
    about: "Testing NDK",
    picture: "https://example.com/avatar.jpg",
});

// Generate contact list (kind 3)
const contacts = await generator.contactList(["pubkey1", "pubkey2", "pubkey3"]);

Advanced Event Generation

Custom Event Creation

// Create a custom event with specific properties
const customEvent = await generator.createEvent({
    kind: 1,
    content: "Custom content",
    tags: [
        ["p", "pubkey1"],
        ["e", "event1"],
    ],
});

// Create an encrypted direct message
const encryptedDM = await generator.encryptedDM("recipient_pubkey", "Secret message");

// Create a reaction event
const reaction = await generator.reaction(
    "target_event_id",
    "+", // Like reaction
);

Event with Tags

// Create an event with multiple tag types
const taggedEvent = await generator.createEvent({
    kind: 1,
    content: "Tagged content",
    tags: [
        ["p", "pubkey1", "wss://relay.example"],
        ["e", "event1", "wss://relay.example", "reply"],
        ["t", "testing"],
        ["r", "https://example.com"],
    ],
});

Parametric Events

// Generate events with specific parameters
const paramEvent = await generator.createEvent({
    kind: 1,
    content: "Parametric content",
    created_at: Math.floor(Date.now() / 1000),
    tags: [],
    pubkey: "custom_pubkey", // Override default pubkey
});

// Generate multiple events
const events = await Promise.all([
    generator.textNote("First note"),
    generator.textNote("Second note"),
    generator.textNote("Third note"),
]);

Testing Scenarios

Event Verification

// Test event verification
const event = await generator.textNote("Test message");

expect(event.kind).toBe(1);
expect(event.content).toBe("Test message");
expect(event.sig).toBeDefined();
expect(event.id).toBeDefined();
expect(event.pubkey).toBeDefined();

Event Relationships

// Create a thread of related events
const rootEvent = await generator.textNote("Root message");
const replyEvent = await generator.createEvent({
    kind: 1,
    content: "Reply message",
    tags: [
        ["e", rootEvent.id, "", "root"],
        ["p", rootEvent.pubkey],
    ],
});

// Create a reaction to the reply
const reactionEvent = await generator.reaction(replyEvent.id, "+");

Testing Event Processing

// Test event processing with mock relay
import { RelayMock } from "@nostr-dev-kit/ndk/test";

const relay = new RelayMock("wss://test.relay");
const events = [];

// Subscribe to events
relay.subscribe({
    subId: "test",
    filters: [{ kinds: [1] }],
    eventReceived: (event) => events.push(event),
});

// Generate and simulate events
const event1 = await generator.textNote("First");
const event2 = await generator.textNote("Second");

await relay.simulateEvent(event1);
await relay.simulateEvent(event2);

expect(events).toHaveLength(2);

Best Practices

1. Reset generator before tests:

beforeEach(() => {
    EventGenerator.setNDK(new NDK());
});

2. Use consistent timestamps for deterministic testing:

const timestamp = Math.floor(Date.now() / 1000);
const event = await generator.createEvent({
    kind: 1,
    content: "Test",
    created_at: timestamp,
});

3. Test event validation:

const event = await generator.textNote("Test");
expect(event.verify()).resolves.toBe(true);

4. Generate related events:

// Create a conversation thread
const thread = [];
const root = await generator.textNote("Root");
thread.push(root);

for (let i = 0; i < 3; i++) {
    const reply = await generator.createEvent({
        kind: 1,
        content: `Reply ${i + 1}`,
        tags: [
            ["e", thread[i].id, "", "reply"],
            ["p", thread[i].pubkey],
        ],
    });
    thread.push(reply);
}