fix error event

nip05 says `NIP-05 assumes the <local-part> part will be restricted to the characters a-z0-9-_., case insensitive`

So a lot of people is starting the names with uppercase. See here:

`https://nostr-check.com/.well-known/nostr.json`

So I think we should change the regex to accept lowercase or uppercase.

Another way to do it would be to do a `.toLowerCase` at the beginning, but then we would need to do this search ignoring the case:

```
if (!res?.names?.[name])
```

So maybe for now this is enough?

.github/workflows/test.yml

@@ -1,8 +1,7 @@
 name: test every commit
 on:
-  push:
+  - push
-    branches:
+  - pull_request
-      - master
 
 jobs:
   test:

README.md

@@ -2,7 +2,7 @@
 
 Tools for developing [Nostr](https://github.com/fiatjaf/nostr) clients.
 
-Very lean on dependencies.
+Only depends on _@scure_ and _@noble_ packages.
 
 ## Usage
 
@@ -30,11 +30,11 @@ let event = {
   kind: 1,
   created_at: Math.floor(Date.now() / 1000),
   tags: [],
-  content: 'hello'
+  content: 'hello',
+  pubkey: getPublicKey(privateKey)
 }
 
 event.id = getEventHash(event)
-event.pubkey = getPublicKey(privateKey)
 event.sig = signEvent(event, privateKey)
 
 let ok = validateEvent(event)
@@ -102,13 +102,13 @@ event.sig = signEvent(event, sk)
 
 let pub = relay.publish(event)
 pub.on('ok', () => {
-  console.log(`{relay.url} has accepted our event`)
+  console.log(`${relay.url} has accepted our event`)
 })
 pub.on('seen', () => {
-  console.log(`we saw the event on {relay.url}`)
+  console.log(`we saw the event on ${relay.url}`)
 })
 pub.on('failed', reason => {
-  console.log(`failed to publish to {relay.url}: ${reason}`)
+  console.log(`failed to publish to ${relay.url}: ${reason}`)
 })
 
 await relay.close()
@@ -182,7 +182,7 @@ let pk2 = getPublicKey(sk2)
 
 // on the sender side
 let message = 'hello'
-let ciphertext = await nip04.encrypt(sk1, pk2, 'hello')
+let ciphertext = await nip04.encrypt(sk1, pk2, message)
 
 let event = {
   kind: 4,
@@ -196,7 +196,7 @@ sendEvent(event)
 
 // on the receiver side
 sub.on('event', (event) => {
-  let sender = event.tags.find(([k, v]) => k === 'p' && && v && v !== '')[1]
+  let sender = event.tags.find(([k, v]) => k === 'p' && v && v !== '')[1]
   pk1 === sender
   let plaintext = await nip04.decrypt(sk2, pk1, event.content)
 })

event.test.js

@@ -4,7 +4,6 @@ const {
   validateEvent,
   verifySignature,
   signEvent,
-  getEventHash,
   getPublicKey
 } = require('./lib/nostr.cjs')
 
@@ -35,15 +34,15 @@ test('validate event', () => {
 })
 
 test('check signature', async () => {
-  expect(await verifySignature(event)).toBeTruthy()
+  expect(verifySignature(event)).toBeTruthy()
 })
 
 test('sign event', async () => {
-  let sig = await signEvent(unsigned, privateKey)
-  let hash = getEventHash(unsigned)
   let pubkey = getPublicKey(privateKey)
+  let authored = {...unsigned, pubkey}
 
-  let signed = {...unsigned, id: hash, sig, pubkey}
+  let sig = signEvent(authored, privateKey)
+  let signed = {...authored, sig}
 
-  expect(await verifySignature(signed)).toBeTruthy()
+  expect(verifySignature(signed)).toBeTruthy()
 })

event.ts

@@ -3,7 +3,6 @@ import {sha256} from '@noble/hashes/sha256'
 
 import {utf8Encoder} from './utils'
 
-
 /* eslint-disable no-unused-vars */
 export enum Kind {
   Metadata = 0,
@@ -17,7 +16,7 @@ export enum Kind {
   ChannelMetadata = 41,
   ChannelMessage = 42,
   ChannelHideMessage = 43,
-  ChannelMuteUser = 44,
+  ChannelMuteUser = 44
 }
 
 export type Event = {
@@ -41,6 +40,9 @@ export function getBlankEvent(): Event {
 }
 
 export function serializeEvent(evt: Event): string {
+  if (!validateEvent(evt))
+    throw new Error("can't serialize event with wrong or missing properties")
+
   return JSON.stringify([
     0,
     evt.pubkey,
@@ -57,9 +59,10 @@ export function getEventHash(event: Event): string {
 }
 
 export function validateEvent(event: Event): boolean {
-  if (event.id !== getEventHash(event)) return false
   if (typeof event.content !== 'string') return false
   if (typeof event.created_at !== 'number') return false
+  if (typeof event.pubkey !== 'string') return false
+  if (!event.pubkey.match(/^[a-f0-9]{64}$/)) return false
 
   if (!Array.isArray(event.tags)) return false
   for (let i = 0; i < event.tags.length; i++) {
@@ -73,10 +76,12 @@ export function validateEvent(event: Event): boolean {
   return true
 }
 
-export function verifySignature(
+export function verifySignature(event: Event & {sig: string}): boolean {
-  event: Event & {id: string; sig: string}
+  return secp256k1.schnorr.verifySync(
-): boolean {
+    event.sig,
-  return secp256k1.schnorr.verifySync(event.sig, event.id, event.pubkey)
+    getEventHash(event),
+    event.pubkey
+  )
 }
 
 export function signEvent(event: Event, key: string): string {

fakejson.test.js

@@ -0,0 +1,35 @@
+/* eslint-env jest */
+
+const {fj} = require('./lib/nostr.cjs')
+
+test('match id', () => {
+  expect(
+    fj.matchEventId(
+      `["EVENT","nostril-query",{"tags":[],"content":"so did we cut all corners and p2p stuff in order to make a decentralized social network that was fast and worked, but in the end what we got was a lot of very slow clients that can't handle the traffic of one jack dorsey tweet?","sig":"ca62629d189edebb8f0811cfa0ac53015013df5f305dcba3f411ba15cfc4074d8c2d517ee7d9e81c9eb72a7328bfbe31c9122156397565ac55e740404e2b1fe7","id":"fef2a50f7d9d3d5a5f38ee761bc087ec16198d3f0140df6d1e8193abf7c2b146","kind":1,"pubkey":"3bf0c63fcb93463407af97a5e5ee64fa883d107ef9e558472c4eb9aaaefa459d","created_at":1671150419}]`,
+      'fef2a50f7d9d3d5a5f38ee761bc087ec16198d3f0140df6d1e8193abf7c2b146'
+    )
+  ).toBeTruthy()
+
+  expect(
+    fj.matchEventId(
+      `["EVENT","nostril-query",{"content":"a bunch of mfs interacted with my post using what I assume were \"likes\": https://nostr.build/i/964.png","created_at":1672506879,"id":"f40bdd0905137ad60482537e260890ab50b0863bf16e67cf9383f203bd26c96f","kind":1,"pubkey":"3bf0c63fcb93463407af97a5e5ee64fa883d107ef9e558472c4eb9aaaefa459d","sig":"8b825d2d4096f0643b18ca39da59ec07a682cd8a3e717f119c845037573d98099f5bea94ec7ddedd5600c8020144a255ed52882a911f7f7ada6d6abb3c0a1eb4","tags":[]}]`,
+      'fef2a50f7d9d3d5a5f38ee761bc087ec16198d3f0140df6d1e8193abf7c2b146'
+    )
+  ).toBeFalsy()
+})
+
+test('match kind', () => {
+  expect(
+    fj.matchEventKind(
+      `["EVENT","nostril-query",{"tags":[],"content":"so did we cut all corners and p2p stuff in order to make a decentralized social network that was fast and worked, but in the end what we got was a lot of very slow clients that can't handle the traffic of one jack dorsey tweet?","sig":"ca62629d189edebb8f0811cfa0ac53015013df5f305dcba3f411ba15cfc4074d8c2d517ee7d9e81c9eb72a7328bfbe31c9122156397565ac55e740404e2b1fe7","id":"fef2a50f7d9d3d5a5f38ee761bc087ec16198d3f0140df6d1e8193abf7c2b146","kind":1,"pubkey":"3bf0c63fcb93463407af97a5e5ee64fa883d107ef9e558472c4eb9aaaefa459d","created_at":1671150419}]`,
+      1
+    )
+  ).toBeTruthy()
+
+  expect(
+    fj.matchEventKind(
+      `["EVENT","nostril-query",{"content":"{\"name\":\"fiatjaf\",\"about\":\"buy my merch at fiatjaf store\",\"picture\":\"https://fiatjaf.com/static/favicon.jpg\",\"nip05\":\"_@fiatjaf.com\"}","created_at":1671217411,"id":"b52f93f6dfecf9d81f59062827cd941412a0e8398dda60baf960b17499b88900","kind":12720,"pubkey":"3bf0c63fcb93463407af97a5e5ee64fa883d107ef9e558472c4eb9aaaefa459d","sig":"fc1ea5d45fa5ed0526faed06e8fc7a558e60d1b213e9714f440828584ee999b93407092f9b04deea7e504fa034fc0428f31f7f0f95417b3280ebe6004b80b470","tags":[]}]`,
+      12720
+    )
+  ).toBeTruthy()
+})

fakejson.ts

@@ -0,0 +1,26 @@
+export function getHex64(json: string, field: string): string {
+  let len = field.length + 3
+  let idx = json.indexOf(`"${field}":`) + len
+  let s = json.slice(idx).indexOf(`"`) + idx + 1
+  return json.slice(s, s + 64)
+}
+
+export function getInt(json: string, field: string): number {
+  let len = field.length
+  let idx = json.indexOf(`"${field}":`) + len + 3
+  let sliced = json.slice(idx)
+  let end = Math.min(sliced.indexOf(','), sliced.indexOf('}'))
+  return parseInt(sliced.slice(0, end), 10)
+}
+
+export function matchEventId(json: string, id: string): boolean {
+  return id === getHex64(json, 'id')
+}
+
+export function matchEventPubkey(json: string, pubkey: string): boolean {
+  return pubkey === getHex64(json, 'pubkey')
+}
+
+export function matchEventKind(json: string, kind: number): boolean {
+  return kind === getInt(json, 'kind')
+}

index.ts

@@ -9,6 +9,9 @@ export * as nip06 from './nip06'
 export * as nip19 from './nip19'
 export * as nip26 from './nip26'
 
+export * as fj from './fakejson'
+export * as utils from './utils'
+
 // monkey patch secp256k1
 import * as secp256k1 from '@noble/secp256k1'
 import {hmac} from '@noble/hashes/hmac'

nip04.ts

@@ -1,6 +1,6 @@
 import {randomBytes} from '@noble/hashes/utils'
 import * as secp256k1 from '@noble/secp256k1'
-import {encode as b64encode, decode as b64decode} from 'base64-arraybuffer'
+import {base64} from '@scure/base'
 
 import {utf8Decoder, utf8Encoder} from './utils'
 
@@ -26,8 +26,8 @@ export async function encrypt(
     cryptoKey,
     plaintext
   )
-  let ctb64 = b64encode(ciphertext)
+  let ctb64 = base64.encode(new Uint8Array(ciphertext))
-  let ivb64 = b64encode(iv.buffer)
+  let ivb64 = base64.encode(new Uint8Array(iv.buffer))
 
   return `${ctb64}?iv=${ivb64}`
 }
@@ -48,8 +48,8 @@ export async function decrypt(
     false,
     ['decrypt']
   )
-  let ciphertext = b64decode(ctb64)
+  let ciphertext = base64.decode(ctb64)
-  let iv = b64decode(ivb64)
+  let iv = base64.decode(ivb64)
 
   let plaintext = await crypto.subtle.decrypt(
     {name: 'AES-CBC', iv},

nip05.ts

@@ -36,7 +36,7 @@ export async function queryProfile(
     name = '_'
   }
 
-  if (!name.match(/^[a-z0-9-_]+$/)) return null
+  if (!name.match(/^[A-Za-z0-9-_]+$/)) return null
 
   let res = await (
     await _fetch(`https://${domain}/.well-known/nostr.json?name=${name}`)

nip06.test.js

@@ -0,0 +1,15 @@
+/* eslint-env jest */
+const {nip06} = require('./lib/nostr.cjs')
+
+test('generate private key from a mnemonic', async () => {
+  const mnemonic = 'zoo zoo zoo zoo zoo zoo zoo zoo zoo zoo zoo wrong'
+  const privateKey = nip06.privateKeyFromSeedWords(mnemonic)
+  expect(privateKey).toEqual('c26cf31d8ba425b555ca27d00ca71b5008004f2f662470f8c8131822ec129fe2')
+})
+
+test('generate private key from a mnemonic and passphrase', async () => {
+  const mnemonic = 'zoo zoo zoo zoo zoo zoo zoo zoo zoo zoo zoo wrong'
+  const passphrase = '123'
+  const privateKey = nip06.privateKeyFromSeedWords(mnemonic, passphrase)
+  expect(privateKey).toEqual('55a22b8203273d0aaf24c22c8fbe99608e70c524b17265641074281c8b978ae4')
+})

nip06.ts

@@ -7,8 +7,8 @@ import {
 } from '@scure/bip39'
 import {HDKey} from '@scure/bip32'
 
-export function privateKeyFromSeedWords(mnemonic: string): string {
+export function privateKeyFromSeedWords(mnemonic: string, passphrase?: string): string {
-  let root = HDKey.fromMasterSeed(mnemonicToSeedSync(mnemonic))
+  let root = HDKey.fromMasterSeed(mnemonicToSeedSync(mnemonic, passphrase))
   let privateKey = root.derive(`m/44'/1237'/0'/0/0`).privateKey
   if (!privateKey) throw new Error('could not derive private key')
   return secp256k1.utils.bytesToHex(privateKey)

nip19.ts

@@ -1,8 +1,10 @@
 import * as secp256k1 from '@noble/secp256k1'
-import {bech32} from 'bech32'
+import {bech32} from '@scure/base'
 
 import {utf8Decoder, utf8Encoder} from './utils'
 
+const Bech32MaxSize = 5000
+
 export type ProfilePointer = {
   pubkey: string // hex
   relays?: string[]
@@ -17,7 +19,7 @@ export function decode(nip19: string): {
   type: string
   data: ProfilePointer | EventPointer | string
 } {
-  let {prefix, words} = bech32.decode(nip19, 1000)
+  let {prefix, words} = bech32.decode(nip19, Bech32MaxSize)
   let data = new Uint8Array(bech32.fromWords(words))
 
   if (prefix === 'nprofile') {
@@ -87,7 +89,7 @@ export function noteEncode(hex: string): string {
 function encodeBytes(prefix: string, hex: string): string {
   let data = secp256k1.utils.hexToBytes(hex)
   let words = bech32.toWords(data)
-  return bech32.encode(prefix, words, 1000)
+  return bech32.encode(prefix, words, Bech32MaxSize)
 }
 
 export function nprofileEncode(profile: ProfilePointer): string {
@@ -96,7 +98,7 @@ export function nprofileEncode(profile: ProfilePointer): string {
     1: (profile.relays || []).map(url => utf8Encoder.encode(url))
   })
   let words = bech32.toWords(data)
-  return bech32.encode('nprofile', words, 1000)
+  return bech32.encode('nprofile', words, Bech32MaxSize)
 }
 
 export function neventEncode(event: EventPointer): string {
@@ -105,7 +107,7 @@ export function neventEncode(event: EventPointer): string {
     1: (event.relays || []).map(url => utf8Encoder.encode(url))
   })
   let words = bech32.toWords(data)
-  return bech32.encode('nevent', words, 1000)
+  return bech32.encode('nevent', words, Bech32MaxSize)
 }
 
 function encodeTLV(tlv: TLV): Uint8Array {

package.json

@@ -1,6 +1,6 @@
 {
   "name": "nostr-tools",
-  "version": "1.0.1",
+  "version": "1.2.1",
   "description": "Tools for making a Nostr client.",
   "repository": {
     "type": "git",
@@ -11,10 +11,9 @@
   "dependencies": {
     "@noble/hashes": "^0.5.7",
     "@noble/secp256k1": "^1.7.0",
+    "@scure/base": "^1.1.1",
     "@scure/bip32": "^1.1.1",
-    "@scure/bip39": "^1.1.0",
+    "@scure/bip39": "^1.1.0"
-    "base64-arraybuffer": "^1.0.2",
-    "bech32": "^2.0.0"
   },
   "keywords": [
     "decentralization",

relay.test.js

@@ -98,7 +98,7 @@ test('listening (twice) and publishing', async () => {
     content: 'nostr-tools test suite'
   }
   event.id = getEventHash(event)
-  event.sig = await signEvent(event, sk)
+  event.sig = signEvent(event, sk)
 
   relay.publish(event)
   return expect(

relay.ts

@@ -2,6 +2,7 @@
 
 import {Event, verifySignature, validateEvent} from './event'
 import {Filter, matchFilters} from './filter'
+import {getHex64} from './fakejson'
 
 type RelayEvent = 'connect' | 'disconnect' | 'error' | 'notice'
 
@@ -31,15 +32,21 @@ type SubscriptionOptions = {
   id?: string
 }
 
-export function relayInit(url: string): Relay {
+export function relayInit(
+  url: string,
+  alreadyHaveEvent: (id: string) => boolean = () => false
+): Relay {
   var ws: WebSocket
   var resolveClose: () => void
-  var untilOpen: Promise<void>
+  var setOpen: (value: PromiseLike<void> | void) => void
+  var untilOpen = new Promise<void>(resolve => {
+    setOpen = resolve
+  })
   var openSubs: {[id: string]: {filters: Filter[]} & SubscriptionOptions} = {}
   var listeners: {
     connect: Array<() => void>
     disconnect: Array<() => void>
-    error: Array<() => void>
+    error: Array<(e: globalThis.Event) => void>
     notice: Array<(msg: string) => void>
   } = {
     connect: [],
@@ -67,30 +74,48 @@ export function relayInit(url: string): Relay {
 
       ws.onopen = () => {
         listeners.connect.forEach(cb => cb())
+        setOpen()
         resolve()
       }
-      ws.onerror = () => {
+      ws.onerror = (e: globalThis.Event) => {
-        listeners.error.forEach(cb => cb())
+        listeners.error.forEach(cb => cb(e))
-        reject()
+        reject(e)
       }
       ws.onclose = async () => {
         listeners.disconnect.forEach(cb => cb())
         resolveClose && resolveClose()
       }
 
-      ws.onmessage = async e => {
+      let incomingMessageQueue: string[] = []
-        var data
+      let handleNextInterval: any
-        try {
+
-          data = JSON.parse(e.data)
+      ws.onmessage = e => {
-        } catch (err) {
+        incomingMessageQueue.push(e.data)
-          data = e.data
+        if (!handleNextInterval) {
+          handleNextInterval = setInterval(handleNext, 0)
+        }
+      }
+
+      function handleNext() {
+        if (incomingMessageQueue.length === 0) {
+          clearInterval(handleNextInterval)
+          handleNextInterval = null
+          return
         }
 
-        if (data.length >= 1) {
+        var json = incomingMessageQueue.shift()
+        if (!json || alreadyHaveEvent(getHex64(json, 'id'))) {
+          return
+        }
+
+        try {
+          let data = JSON.parse(json)
+
+          // we won't do any checks against the data since all failures (i.e. invalid messages from relays)
+          // will naturally be caught by the encompassing try..catch block
+
           switch (data[0]) {
             case 'EVENT':
-              if (data.length !== 3) return // ignore empty or malformed EVENT
-
               let id = data[1]
               let event = data[2]
               if (
@@ -104,13 +129,11 @@ export function relayInit(url: string): Relay {
               }
               return
             case 'EOSE': {
-              if (data.length !== 2) return // ignore empty or malformed EOSE
               let id = data[1]
               ;(subListeners[id]?.eose || []).forEach(cb => cb())
               return
             }
             case 'OK': {
-              if (data.length < 3) return // ignore empty or malformed OK
               let id: string = data[1]
               let ok: boolean = data[2]
               let reason: string = data[3] || ''
@@ -119,11 +142,12 @@ export function relayInit(url: string): Relay {
               return
             }
             case 'NOTICE':
-              if (data.length !== 2) return // ignore empty or malformed NOTICE
               let notice = data[1]
               listeners.notice.forEach(cb => cb(notice))
               return
           }
+        } catch (err) {
+          return
         }
       }
     })
@@ -138,7 +162,11 @@ export function relayInit(url: string): Relay {
     let msg = JSON.stringify(params)
 
     await untilOpen
-    ws.send(msg)
+    try {
+      ws.send(msg)
+    } catch (err) {
+      console.log(err)
+    }
   }
 
   const sub = (
@@ -186,19 +214,13 @@ export function relayInit(url: string): Relay {
   return {
     url,
     sub,
-    on: (
+    on: (type: RelayEvent, cb: any): void => {
-      type: RelayEvent,
-      cb: any
-    ): void => {
       listeners[type].push(cb)
       if (type === 'connect' && ws?.readyState === 1) {
         cb()
       }
     },
-    off: (
+    off: (type: RelayEvent, cb: any): void => {
-      type: RelayEvent,
-      cb: any
-    ): void => {
       let index = listeners[type].indexOf(cb)
       if (index !== -1) listeners[type].splice(index, 1)
     },

utils.test.js

@@ -0,0 +1,183 @@
+/* eslint-env jest */
+
+const {utils} = require('./lib/nostr.cjs')
+
+const {insertEventIntoAscendingList, insertEventIntoDescendingList} = utils
+
+describe('inserting into a desc sorted list of events', () => {
+  test('insert into an empty list', async () => {
+    const list0 = []
+    expect(
+      insertEventIntoDescendingList(list0, {id: 'abc', created_at: 10})
+    ).toHaveLength(1)
+  })
+
+  test('insert in the beginning of a list', async () => {
+    const list0 = [{created_at: 20}, {created_at: 10}]
+    const list1 = insertEventIntoDescendingList(list0, {
+      id: 'abc',
+      created_at: 30
+    })
+    expect(list1).toHaveLength(3)
+    expect(list1[0].id).toBe('abc')
+  })
+
+  test('insert in the beginning of a list with same created_at', async () => {
+    const list0 = [{created_at: 30}, {created_at: 20}, {created_at: 10}]
+    const list1 = insertEventIntoDescendingList(list0, {
+      id: 'abc',
+      created_at: 30
+    })
+    expect(list1).toHaveLength(4)
+    expect(list1[0].id).toBe('abc')
+  })
+
+  test('insert in the middle of a list', async () => {
+    const list0 = [
+      {created_at: 30},
+      {created_at: 20},
+      {created_at: 10},
+      {created_at: 1}
+    ]
+    const list1 = insertEventIntoDescendingList(list0, {
+      id: 'abc',
+      created_at: 15
+    })
+    expect(list1).toHaveLength(5)
+    expect(list1[2].id).toBe('abc')
+  })
+
+  test('insert in the end of a list', async () => {
+    const list0 = [
+      {created_at: 20},
+      {created_at: 20},
+      {created_at: 20},
+      {created_at: 20},
+      {created_at: 10}
+    ]
+    const list1 = insertEventIntoDescendingList(list0, {
+      id: 'abc',
+      created_at: 5
+    })
+    expect(list1).toHaveLength(6)
+    expect(list1.slice(-1)[0].id).toBe('abc')
+  })
+
+  test('insert in the last-to-end of a list with same created_at', async () => {
+    const list0 = [
+      {created_at: 20},
+      {created_at: 20},
+      {created_at: 20},
+      {created_at: 20},
+      {created_at: 10}
+    ]
+    const list1 = insertEventIntoDescendingList(list0, {
+      id: 'abc',
+      created_at: 10
+    })
+    expect(list1).toHaveLength(6)
+    expect(list1.slice(-2)[0].id).toBe('abc')
+  })
+
+  test('do not insert duplicates', async () => {
+    const list0 = [
+      {created_at: 20},
+      {created_at: 20},
+      {created_at: 10, id: 'abc'}
+    ]
+    const list1 = insertEventIntoDescendingList(list0, {
+      id: 'abc',
+      created_at: 10
+    })
+    expect(list1).toHaveLength(3)
+  })
+})
+
+describe('inserting into a asc sorted list of events', () => {
+  test('insert into an empty list', async () => {
+    const list0 = []
+    expect(
+      insertEventIntoAscendingList(list0, {id: 'abc', created_at: 10})
+    ).toHaveLength(1)
+  })
+
+  test('insert in the beginning of a list', async () => {
+    const list0 = [{created_at: 10}, {created_at: 20}]
+    const list1 = insertEventIntoAscendingList(list0, {
+      id: 'abc',
+      created_at: 1
+    })
+    expect(list1).toHaveLength(3)
+    expect(list1[0].id).toBe('abc')
+  })
+
+  test('insert in the beginning of a list with same created_at', async () => {
+    const list0 = [{created_at: 10}, {created_at: 20}, {created_at: 30}]
+    const list1 = insertEventIntoAscendingList(list0, {
+      id: 'abc',
+      created_at: 10
+    })
+    expect(list1).toHaveLength(4)
+    expect(list1[0].id).toBe('abc')
+  })
+
+  test('insert in the middle of a list', async () => {
+    const list0 = [
+      {created_at: 10},
+      {created_at: 20},
+      {created_at: 30},
+      {created_at: 40}
+    ]
+    const list1 = insertEventIntoAscendingList(list0, {
+      id: 'abc',
+      created_at: 25
+    })
+    expect(list1).toHaveLength(5)
+    expect(list1[2].id).toBe('abc')
+  })
+
+  test('insert in the end of a list', async () => {
+    const list0 = [
+      {created_at: 20},
+      {created_at: 20},
+      {created_at: 20},
+      {created_at: 20},
+      {created_at: 40}
+    ]
+    const list1 = insertEventIntoAscendingList(list0, {
+      id: 'abc',
+      created_at: 50
+    })
+    expect(list1).toHaveLength(6)
+    expect(list1.slice(-1)[0].id).toBe('abc')
+  })
+
+  test('insert in the last-to-end of a list with same created_at', async () => {
+    const list0 = [
+      {created_at: 20},
+      {created_at: 20},
+      {created_at: 20},
+      {created_at: 20},
+      {created_at: 30}
+    ]
+    const list1 = insertEventIntoAscendingList(list0, {
+      id: 'abc',
+      created_at: 30
+    })
+    expect(list1).toHaveLength(6)
+    expect(list1.slice(-2)[0].id).toBe('abc')
+  })
+
+  test('do not insert duplicates', async () => {
+    const list0 = [
+      {created_at: 20},
+      {created_at: 20},
+      {created_at: 30, id: 'abc'}
+    ]
+    const list1 = insertEventIntoAscendingList(list0, {
+      id: 'abc',
+      created_at: 30
+    })
+    expect(list1).toHaveLength(3)
+  })
+})

utils.ts

@@ -1,2 +1,97 @@
+import {Event} from './event'
+
 export const utf8Decoder = new TextDecoder('utf-8')
 export const utf8Encoder = new TextEncoder()
+
+//
+// fast insert-into-sorted-array functions adapted from https://github.com/terrymorse58/fast-sorted-array
+//
+export function insertEventIntoDescendingList(
+  sortedArray: Event[],
+  event: Event
+) {
+  let start = 0
+  let end = sortedArray.length - 1
+  let midPoint
+  let position = start
+
+  if (end < 0) {
+    position = 0
+  } else if (event.created_at < sortedArray[end].created_at) {
+    position = end + 1
+  } else if (event.created_at >= sortedArray[start].created_at) {
+    position = start
+  } else
+    while (true) {
+      if (end <= start + 1) {
+        position = end
+        break
+      }
+      midPoint = Math.floor(start + (end - start) / 2)
+      if (sortedArray[midPoint].created_at > event.created_at) {
+        start = midPoint
+      } else if (sortedArray[midPoint].created_at < event.created_at) {
+        end = midPoint
+      } else {
+        // aMidPoint === num
+        position = midPoint
+        break
+      }
+    }
+
+  // insert when num is NOT already in (no duplicates)
+  if (sortedArray[position]?.id !== event.id) {
+    return [
+      ...sortedArray.slice(0, position),
+      event,
+      ...sortedArray.slice(position)
+    ]
+  }
+
+  return sortedArray
+}
+
+export function insertEventIntoAscendingList(
+  sortedArray: Event[],
+  event: Event
+) {
+  let start = 0
+  let end = sortedArray.length - 1
+  let midPoint
+  let position = start
+
+  if (end < 0) {
+    position = 0
+  } else if (event.created_at > sortedArray[end].created_at) {
+    position = end + 1
+  } else if (event.created_at <= sortedArray[start].created_at) {
+    position = start
+  } else
+    while (true) {
+      if (end <= start + 1) {
+        position = end
+        break
+      }
+      midPoint = Math.floor(start + (end - start) / 2)
+      if (sortedArray[midPoint].created_at < event.created_at) {
+        start = midPoint
+      } else if (sortedArray[midPoint].created_at > event.created_at) {
+        end = midPoint
+      } else {
+        // aMidPoint === num
+        position = midPoint
+        break
+      }
+    }
+
+  // insert when num is NOT already in (no duplicates)
+  if (sortedArray[position]?.id !== event.id) {
+    return [
+      ...sortedArray.slice(0, position),
+      event,
+      ...sortedArray.slice(position)
+    ]
+  }
+
+  return sortedArray
+}