batchNode.js

var https = require('https');

let DEBUG = true;

let customPayload = {};

let requestOptions = {
  "hostname": "api.batch.com",
  "port": 443,
  "method": "POST",
  "path": "/1.0/" + "<your app api key>" + "/transactional/send",
  "headers": {
    "Content-Type": "application/json",
    "User-Agent": "BatchPushSender 1.0",
    "X-Authorization": "rest key"
  }

};

let apiPayload = {
  "group_id": "batch_push_sender",
  "push_time": "now",
  "message": {
    "body": "<your message body here>"
  },
  "recipients": {
    "tokens": ["<token>"]
  },
  "sandbox": false, // Only for iOS
  "deeplink": "http://google.fr",
  "custom_payload": JSON.stringify(customPayload)
};

let request = https.request(requestOptions, (res) => {
  let data = "";

  res.setEncoding("utf8");
  res.on("data", (chunk) => {
    data += chunk;
  });

  res.on("end", (chunk) => {
    if (DEBUG) {
      console.log("[BatchPushSender] Batch API Request response: %j", data);
    }
  });
});

request.on("error", (e) => {
  if (DEBUG) {
    console.log("[BatchPushSender] Batch API Request error: %j", e);
  }
});

request.write(JSON.stringify(apiPayload));
request.end();

Line 55 should read 'request.write(JSON.stringify(apiPayload));'

As it's missing the ')'