Using slack webhook with node

Question

I am trying to use slack webhook. I can read a lot of variation about how I should proceed, but until now, none of them worked properly.

I am using the request node module to make the api call, but I can change if needed.

First try following this

import request from 'request';
const url = 'https://hooks.slack.com/services/xxx';
const text = '(test)!';
request.post(
  {
    headers : { 'Content-type' : 'application/json' },
    url,
    payload : JSON.stringify({ text }),
  },
  (error, res, body) => console.log(error, body, res.statusCode)
);

I get : null 400 'invalid_payload'

Next try following this

request.post(
  {
    headers : { 'Content-type' : 'application/json' },
    url,
    form : JSON.stringify({ text }),
  },
  (error, res, body) => console.log(error, body, res.statusCode)
);

This time, it works, but Slack displays: %28test%29%21 instead of (test)!

Did I miss something?

Answer 1

Based on your second example and the working Postman request this is how I got it to work, forgive my change to require as I am running older node version right now. I am not exactly sure what your data would look like that you want to post to Slack, that may change how you want to assemble this.

const request = require('request');

const url = 'https://hooks.slack.com/services/xxxxx';
const text = '(test)!';
request.post(
  {
    headers : { 'Content-type' : 'application/json' },
    url,
    form : {payload: JSON.stringify({ text } )}
  },
  (error, res, body) => console.log(error, body, res.statusCode)
);

If you want to use request you may want to check how slack-node is posting the data, here the relevant snipped from slack-node

Slack.prototype.webhook = function(options, callback) {
    var emoji, payload;
    emoji = this.detectEmoji(options.icon_emoji);
    payload = {
      response_type: options.response_type || 'ephemeral',
      channel: options.channel,
      text: options.text,
      username: options.username,
      attachments: options.attachments,
      link_names: options.link_names || 0
    };
    payload[emoji.key] = emoji.val;
    return request({
      method: "POST",
      url: this.webhookUrl,
      body: JSON.stringify(payload),
      timeout: this.timeout,
      maxAttempts: this.maxAttempts,
      retryDelay: 0
    }, function(err, body, response) {
      if (err != null) {
        return callback(err);
      }
      return callback(null, {
        status: err || response !== "ok" ? "fail" : "ok",
        statusCode: body.statusCode,
        headers: body.headers,
        response: response
      });
    });
  };