Added downloadFile sugar method

README.md

@@ -296,4 +296,17 @@ See: https://core.telegram.org/bots/api#getfile
 
 * **Promise** *promise* Promise which will have *fileURI* in resolve callback
 
+## downloadFile(fileId, downloadDir)
+
+Downloads file in the specified folder.
+This is just a sugar for (getFile)[#getfilefiled] method
+
+### Params:
+* **String** *fileId* File identifier to get info about
+* **String** *downloadDir* Absolute path to the folder in which file will be saved
+
+### Return:
+
+* **Promise** *promise* Promise, which will have *filePath* of downloaded file in resolve callback
+
 <!-- End src/telegram.js -->

package.json

@@ -27,6 +27,7 @@
   },
   "devDependencies": {
     "coveralls": "^2.11.2",
+    "del": "^2.0.2",
     "istanbul": "^0.3.17",
     "mocha": "^2.2.5",
     "mocha-lcov-reporter": "0.0.2",

src/telegram.js

@@ -434,4 +434,33 @@ TelegramBot.prototype.getFileLink = function(fileId) {
 	});
 };
 
+/**
+ * Downloads file in the specified folder.
+ * This is just a sugar for (getFile)[#getfilefiled] method
+ *
+ * @param  {String} fileId  File identifier to get info about
+ * @param  {String} downloadDir Absolute path to the folder in which file will be saved
+ * @return {Promise} promise Promise, which will have *filePath* of downloaded file in resolve callback
+ */
+TelegramBot.prototype.downloadFile = function(fileId, downloadDir) {
+
+	var bot = this;
+
+	return new Promise(function(resolve, reject) {
+		
+		bot.getFileLink(fileId).then(function(fileURI) {
+			// Apparently, this is not the safest method to get the file name,
+			// but I am pretty sure that Telegram will not include slashes when generating names
+			var fileName = fileURI.slice(fileURI.lastIndexOf('/') + 1);
+			var filePath = downloadDir + '/' + fileName;
+
+			request({uri: fileURI})
+				.pipe(fs.createWriteStream(filePath))
+				.on('close', function() {
+					resolve(filePath);
+				});
+		});		
+	});
+}
+
 module.exports = TelegramBot;

test/index.js

@@ -2,6 +2,7 @@ var TelegramPolling = require('../src/telegramPolling');
 var Telegram = require('../index');
 var request = require('request');
 var should = require('should');
+var del = require('del');
 var fs = require('fs');
 
 process.env.NODE_TLS_REJECT_UNAUTHORIZED = "0";
@@ -420,6 +421,38 @@ describe('Telegram', function () {
     });
   });
 
+  describe('#downloadFile', function () {
+
+  	var fileId;
+  	var downloadPath = __dirname;
+
+  	// To get a file we have to send some file first
+    it('should send a photo from file', function (done) {
+
+      var bot = new Telegram(TOKEN);
+      var photo = __dirname + '/bot.gif';
+
+      bot.sendPhoto(USERID, photo).then(function (resp) {
+        resp.should.be.an.instanceOf(Object);
+        fileId = resp.photo[0].file_id;
+        done();
+      });
+    });
+
+    it('should download a file', function (done) {
+
+      var bot = new Telegram(TOKEN);
+
+      bot.downloadFile(fileId, downloadPath).then(function (filePath) {
+        filePath.should.be.an.instanceOf(String);
+        fs.existsSync(filePath).should.be.true();
+        del(filePath); // Clean folder after test
+        done();
+      });
+    });
+  });
+
+
 }); // End Telegram