First working version with tests

Author: piranna

.gitignore

@@ -0,0 +1 @@
+node_modules/

index.js

@@ -0,0 +1,80 @@
+var Duplex = require('stream').Duplex
+
+var inherits = require('inherits')
+var Telegram = require('telegram-bot-api')
+
+
+/**
+ * Send data as messages to a Telegram chat
+ *
+ * @param {Object} [options]
+ * @param {Integer} [options.worksheet=1]
+ */
+function TelegramLog(token, chat_id, options)
+{
+  if(!(this instanceof TelegramLog))
+    return new TelegramLog(token, chat_id, options)
+
+  var self = this
+
+  options = options || {}
+  options.objectMode = true
+
+  TelegramLog.super_.call(this, options)
+
+
+  if(!token)   throw 'Missing token'
+  if(!chat_id) throw 'Missing chat_id'
+
+
+  var api = new Telegram(
+  {
+    token: token,
+    updates:
+    {
+      enabled: true
+    }
+  })
+
+  api.on('message', function(message)
+  {
+    if(message.chat.id !== chat_id)
+    {
+      var error = new Error('Received message for not-listening chat')
+          error.data = message
+
+      return self.emit('error', error)
+    }
+
+    self.push(message.text)
+  })
+
+
+  /**
+   * Write a streamed row on the worksheet
+   *
+   * @param {Object} data
+   * @param {*} _ - ignored
+   * @param {Function} callback
+   *
+   * @private
+   */
+  this._write = function(chunk, _, callback)
+  {
+    if(chunk == null || chunk == '') return callback()
+
+    api.sendMessage(
+    {
+  		chat_id: chat_id,
+  		text: JSON.stringify(chunk)
+  	})
+    .then(callback.bind(null, null), callback)
+  }
+}
+inherits(TelegramLog, Duplex)
+
+
+TelegramLog.prototype._read = function(){}
+
+
+module.exports = TelegramLog

package.json

@@ -0,0 +1,27 @@
+{
+  "name": "telegram-bot-log-stream",
+  "version": "0.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "test": "mocha"
+  },
+  "keywords": [
+    "Context Broker",
+    "Telegram",
+    "stream"
+  ],
+  "author": "Telefónica I+D",
+  "contributors": [
+    "Jesús Leganés Combarro 'piranna' <[email protected]>"
+  ],
+  "license": "AGPL-3.0",
+  "devDependencies": {
+    "mocha": "^2.4.5",
+    "nock": "^7.0.2"
+  },
+  "dependencies": {
+    "inherits": "^2.0.1",
+    "telegram-bot-api": "^1.0.0"
+  }
+}

test.js

@@ -0,0 +1,77 @@
+var assert = require('assert')
+
+var nock = require('nock')
+
+var TelegramLog = require('./index')
+
+nock.disableNetConnect()
+
+
+const SERVER  = 'api.telegram.org'
+const TOKEN   = 'token'
+const CHAT_ID = 'chat_id'
+
+
+var server = nock('https://'+SERVER)
+
+
+afterEach(nock.cleanAll)
+
+
+it('receive update', function(done)
+{
+  var expected = 'asdf'
+
+  server.get('/bot'+TOKEN+'/getUpdates').reply(200,
+  {
+    result:
+    [
+      {
+        update_id: 0,
+        message:
+        {
+          chat:
+          {
+            id: CHAT_ID
+          },
+          text: expected
+        }
+      }
+    ]
+  })
+
+
+  var log = TelegramLog(TOKEN, CHAT_ID)
+
+  log.on('error', done)
+  log.on('data', function(data)
+  {
+    assert.equal(data, expected)
+    done()
+  })
+})
+
+it('send message', function(done)
+{
+  var expected = {a: 'b'}
+
+  server.get('/bot'+TOKEN+'/getUpdates').reply(200,
+  {
+    result:
+    [{
+      update_id: 0,
+      message: {chat: {id: CHAT_ID}}
+    }]
+  })
+  server.post('/bot'+TOKEN+'/sendMessage').reply(function(uri)
+  {
+    done()
+  })
+
+
+  var log = TelegramLog(TOKEN, CHAT_ID)
+
+  log.on('error', done)
+
+  log.write(expected)
+})