Add NIP-40 module for event expiration

nip40.test.ts

@@ -0,0 +1,44 @@
+import { describe, test, expect, jest } from 'bun:test'
+import { buildEvent } from './test-helpers.ts'
+import { getExpiration, isEventExpired, waitForExpire, onExpire } from './nip40.ts'
+
+describe('getExpiration', () => {
+  test('returns the expiration as a Date object', () => {
+    const event = buildEvent({ tags: [['expiration', '123']] })
+    const result = getExpiration(event)
+    expect(result).toEqual(new Date(123000))
+  })
+})
+
+describe('isEventExpired', () => {
+  test('returns true when the event has expired', () => {
+    const event = buildEvent({ tags: [['expiration', '123']] })
+    const result = isEventExpired(event)
+    expect(result).toEqual(true)
+  })
+
+  test('returns false when the event has not expired', () => {
+    const future = Math.floor(Date.now() / 1000) + 10
+    const event = buildEvent({ tags: [['expiration', future.toString()]] })
+    const result = isEventExpired(event)
+    expect(result).toEqual(false)
+  })
+})
+
+describe('waitForExpire', () => {
+  test('returns a promise that resolves when the event expires', async () => {
+    const event = buildEvent({ tags: [['expiration', '123']] })
+    const result = await waitForExpire(event)
+    expect(result).toEqual(event)
+  })
+})
+
+describe('onExpire', () => {
+  test('calls the callback when the event expires', async () => {
+    const event = buildEvent({ tags: [['expiration', '123']] })
+    const callback = jest.fn()
+    onExpire(event, callback)
+    await new Promise((resolve) => setTimeout(resolve, 200))
+    expect(callback).toHaveBeenCalled()
+  })
+})