Split long telegram messages

Author: mbelsky

src/notifier/__tests__/notifier.spec.js

@@ -208,4 +208,47 @@ describe('_notify', () => {
       expect(telegram.sendMessage.mock.calls.length).toBe(0)
     })
   })
+
+  test('splits long telegram messages', async () => {
+    const fetchData = async () => {
+      const match = {
+        stars: 2,
+        id: 2341452,
+        event: 'CLUTCH Season 2',
+        href:
+          'https://www.hltv.org/matches/2341452/w7m-vs-red-canids-clutch-season-2',
+        title: 'W7M vs RED Canids',
+        unixTimestamp: 1589749051000,
+      }
+      const matches = []
+
+      while (matches.length < 100) {
+        matches.push(match)
+      }
+
+      return {
+        matches,
+        timeZoneOffsetsMap: {
+          'Europe/Moscow': 10800,
+        },
+        users: {
+          0: {
+            filter: 1,
+            location: {
+              timeZoneId: 'Europe/Moscow',
+            },
+          },
+        },
+      }
+    }
+
+    await _notify({
+      fetchData,
+      log,
+      telegram,
+      updateUser,
+    })
+
+    expect(telegram.sendMessage.mock.calls.length).toBe(2)
+  })
 })

src/notifier/__tests__/splitLongTelegramMessage.spec.js

@@ -0,0 +1,47 @@
+const { makeUsersTelegramMessages } = require('../makeUsersTelegramMessages')
+const {
+  EmptyFeaturedMatchesMessage,
+  FeaturedMatchesMessage,
+} = require('../messages')
+const { splitLongTelegramMessage } = require('../splitLongTelegramMessage')
+
+const LONG_MESSAGE = `ABC vs XYZ\n\n`.repeat(833) + 'abcdef\n\n123456'
+const UNSPLITABLE_MESSAGE = '0123456789'.repeat(10001)
+
+test('throws `Split function is not defined` error', () => {
+  const message = makeTelegramMessage(
+    new EmptyFeaturedMatchesMessage({ text: LONG_MESSAGE }),
+  )
+
+  expect(() => splitLongTelegramMessage(message)).toThrow()
+})
+
+test('throws `Unsplitable message` error', () => {
+  const message = makeTelegramMessage(
+    new FeaturedMatchesMessage({ text: UNSPLITABLE_MESSAGE }),
+  )
+
+  expect(() => splitLongTelegramMessage(message)).toThrow()
+})
+
+test('splits featured matches message', () => {
+  const message = makeTelegramMessage(
+    new FeaturedMatchesMessage({ text: LONG_MESSAGE }),
+  )
+
+  const result = splitLongTelegramMessage(message)
+
+  expect(result[0]).toBe(`ABC vs XYZ\n\n`.repeat(833).trim())
+  expect(result[1]).toBe('abcdef\n\n123456')
+})
+
+function makeTelegramMessage(smartMessage) {
+  const [{ messages }] = makeUsersTelegramMessages([
+    {
+      messages: [smartMessage],
+    },
+  ])
+  const [message] = messages
+
+  return message
+}

src/notifier/sendMessages.js

@@ -1,3 +1,5 @@
+const { splitLongTelegramMessage } = require('./splitLongTelegramMessage')
+
 exports.sendMessages = async ({
   alerter,
   log,
@@ -49,7 +51,12 @@ exports.sendMessages = async ({
   )
 
   async function sendTelegramMessages({ message, userId }) {
-    return telegram.sendMessage(userId, message.getText(), message.getExtra())
+    const extra = message.getExtra()
+    const texts = splitLongTelegramMessage(message)
+
+    for (const text of texts) {
+      await telegram.sendMessage(userId, text, extra)
+    }
   }
 
   async function sendTelegramMessagesDevelopmentEnviroment(data) {

src/notifier/splitLongTelegramMessage.js

@@ -0,0 +1,42 @@
+const { MESSAGE_TYPES } = require('./consts')
+const MAX_TELEGRAM_MESSAGE_LENGTH = 10000
+
+const splitFunctions = {
+  [MESSAGE_TYPES.favoriteTeamsMatches]: splitMatchesMessage,
+  [MESSAGE_TYPES.featuredMatches]: splitMatchesMessage,
+}
+
+exports.splitLongTelegramMessage = (message) => {
+  const text = message.getText()
+
+  if (text.length <= MAX_TELEGRAM_MESSAGE_LENGTH) {
+    return [text]
+  }
+
+  const type = message.getType()
+  const splitFn = splitFunctions[type]
+
+  if (!splitFn) {
+    throw new Error(`Split function is not defined. Message type='${type}'`)
+  }
+
+  return splitFn(text)
+}
+
+function splitMatchesMessage(text) {
+  if (text.length <= MAX_TELEGRAM_MESSAGE_LENGTH) {
+    return [text]
+  }
+
+  const substring = text.substring(0, MAX_TELEGRAM_MESSAGE_LENGTH).trim()
+  const index = substring.search(/\n\n[^\n]+$/)
+
+  if (-1 === index) {
+    throw new Error('Unsplitable message: ' + text)
+  }
+
+  return [
+    substring.substring(0, index),
+    ...splitMatchesMessage(text.substring(index).trim()),
+  ]
+}