add helper functions for nip-47

event.ts

@@ -31,6 +31,7 @@ export enum Kind {
   Zap = 9735,
   RelayList = 10002,
   ClientAuth = 22242,
+  NwcRequest = 23194,
   HttpAuth = 27235,
   ProfileBadge = 30008,
   BadgeDefinition = 30009,

index.ts

@@ -20,6 +20,7 @@ export * as nip28 from './nip28.ts'
 export * as nip39 from './nip39.ts'
 export * as nip42 from './nip42.ts'
 export * as nip44 from './nip44.ts'
+export * as nip47 from './nip47.ts'
 export * as nip57 from './nip57.ts'
 export * as nip98 from './nip98.ts'
 

nip47.test.ts

@@ -0,0 +1,83 @@
+import {makeNwcRequestEvent, parseConnectionString} from './nip47'
+import {Kind} from './event'
+import {decrypt} from './nip04.ts'
+import crypto from 'node:crypto'
+
+// @ts-ignore
+// eslint-disable-next-line no-undef
+globalThis.crypto = crypto
+
+describe('parseConnectionString', () => {
+  test('returns pubkey, relay, and secret if connection string is valid', () => {
+    const connectionString =
+      'nostr+walletconnect:b889ff5b1513b641e2a139f661a661364979c5beee91842f8f0ef42ab558e9d4?relay=wss%3A%2F%2Frelay.damus.io&secret=71a8c14c1407c113601079c4302dab36460f0ccd0ad506f1f2dc73b5100e4f3c'
+    const {pubkey, relay, secret} = parseConnectionString(connectionString)
+
+    expect(pubkey).toBe(
+      'b889ff5b1513b641e2a139f661a661364979c5beee91842f8f0ef42ab558e9d4'
+    )
+    expect(relay).toBe('wss://relay.damus.io')
+    expect(secret).toBe(
+      '71a8c14c1407c113601079c4302dab36460f0ccd0ad506f1f2dc73b5100e4f3c'
+    )
+  })
+
+  test('throws an error if no pubkey in connection string', async () => {
+    const connectionString =
+      'nostr+walletconnect:relay=wss%3A%2F%2Frelay.damus.io&secret=71a8c14c1407c113601079c4302dab36460f0ccd0ad506f1f2dc73b5100e4f3c'
+
+    expect(() => parseConnectionString(connectionString)).toThrow(
+      'invalid connection string'
+    )
+  })
+
+  test('throws an error if no relay in connection string', async () => {
+    const connectionString =
+      'nostr+walletconnect:b889ff5b1513b641e2a139f661a661364979c5beee91842f8f0ef42ab558e9d4?secret=71a8c14c1407c113601079c4302dab36460f0ccd0ad506f1f2dc73b5100e4f3c'
+
+    expect(() => parseConnectionString(connectionString)).toThrow(
+      'invalid connection string'
+    )
+  })
+
+  test('throws an error if no secret in connection string', async () => {
+    const connectionString =
+      'nostr+walletconnect:b889ff5b1513b641e2a139f661a661364979c5beee91842f8f0ef42ab558e9d4?relay=wss%3A%2F%2Frelay.damus.io'
+
+    expect(() => parseConnectionString(connectionString)).toThrow(
+      'invalid connection string'
+    )
+  })
+})
+
+describe('makeNwcRequestEvent', () => {
+  test('returns a valid NWC request event', async () => {
+    const pubkey =
+      'b889ff5b1513b641e2a139f661a661364979c5beee91842f8f0ef42ab558e9d4'
+    const secret =
+      '71a8c14c1407c113601079c4302dab36460f0ccd0ad506f1f2dc73b5100e4f3c'
+    const invoice =
+      'lnbc210n1pjdgyvupp5x43awdarnfd4mdlsklelux0nyckwfu5c708ykuet8vcjnjp3rnpqdqu2askcmr9wssx7e3q2dshgmmndp5scqzzsxqyz5vqsp52l7y9peq9pka3vd3j7aps7gjnalsmy46ndj2mlkz00dltjgqfumq9qyyssq5fasr5dxed8l4qjfnqq48a02jzss3asf8sly7sfaqtr9w3yu2q9spsxhghs3y9aqdf44zkrrg9jjjdg6amade4h0hulllkwk33eqpucp6d5jye'
+    const timeBefore = Date.now() / 1000
+    const result = await makeNwcRequestEvent({
+      pubkey,
+      secret,
+      invoice
+    })
+    const timeAfter = Date.now() / 1000
+    expect(result.kind).toBe(Kind.NwcRequest)
+    expect(result.created_at).toBeGreaterThan(timeBefore)
+    expect(result.created_at).toBeLessThan(timeAfter)
+    expect(await decrypt(secret, pubkey, result.content)).toEqual(
+      JSON.stringify({
+        method: 'pay_invoice',
+        params: {
+          invoice
+        }
+      })
+    )
+    expect(result.tags).toEqual([['p', pubkey]])
+    expect(result.id).toEqual(expect.any(String))
+    expect(result.sig).toEqual(expect.any(String))
+  })
+})

nip47.ts

@@ -0,0 +1,46 @@
+import {finishEvent} from './event.ts'
+import {encrypt} from './nip04.ts'
+import {Kind} from './event'
+
+export function parseConnectionString(connectionString: string) {
+  const {pathname, searchParams} = new URL(connectionString)
+  const pubkey = pathname
+  const relay = searchParams.get('relay')
+  const secret = searchParams.get('secret')
+
+  if (!pubkey || !relay || !secret) {
+    throw new Error('invalid connection string')
+  }
+
+  return {pubkey, relay, secret}
+}
+
+export async function makeNwcRequestEvent({
+  pubkey,
+  secret,
+  invoice
+}: {
+  pubkey: string
+  secret: string
+  invoice: string
+}) {
+  const content = {
+    method: 'pay_invoice',
+    params: {
+      invoice
+    }
+  }
+  const encryptedContent = await encrypt(
+    secret,
+    pubkey,
+    JSON.stringify(content)
+  )
+  const eventTemplate = {
+    kind: Kind.NwcRequest,
+    created_at: Math.round(Date.now() / 1000),
+    content: encryptedContent,
+    tags: [['p', pubkey]]
+  }
+
+  return finishEvent(eventTemplate, secret)
+}