Slack is a collaboration platform that is a competitor to Microsoft Teams. Slack has a web API that you will utilize in this assignment to create a command-line interface for accessing a Slack workspace. The interface will allow the user to post, browse and search messages from the command line. This kind of utility would be useful in a shell script that automates Slack operations.
Note: Although there are npm modules that provide a nice wrapper around the Slack web API, you may not use them. The point of this assignment is to practice interacting with a web service from Node.js without relying on someone else having written a Node.js library for the service. However, you may use the request module to streamline your HTTP requests.
Create a program named slack.js. When run without any command line arguments, it should display a short help message that lists the commands that it supports, and then exit. See below for the commands.
When it starts, slack.js should retrieve the value of the SLACK_TOKEN environment variable (from the process.env map) and use it as the authorization token for web requests. If SLACK_TOKEN is missing or empty, display an error message and exit immediately.
If SLACK_TOKEN is present, slack.js should perform the command indicated by its command line arguments. The commands are given below.
node slack.js show-channels
The show-channels option should display a list of channel names and topics. Format the output as follows:
Channel name Topic
------------ -------------------------------------------------
general Course announcements and work-based matters
random Non-work banter and water cooler conversation
node slack.js show-users
The show-users option should display a list of users:
User Name
------------ -------------------------------------------------
fred Fred Jones
slackbot slackbot
node slack.js post <channel-name> <message>
The post option should post a message to the specified channel. For example:
node slack.js post general "This is a nifty utility."
On successful post, display “Message successfully posted.”
node slack.js get-posts <channel-name> [<search-word>]
The get-posts option should display a list of messages in the specified channel. Note that the channel name, not the channel id, is provided. If the <search-word> is specified, display only messages containing the word; otherwise, display all messages.
Example:
node slack.js get-posts general
displays all messages in the general channel, while
node slack.js get-posts random cool
displays messages in the random channel containing the word ‘cool’.
Format the output with the username and the message text as follows:
@fred: It's a grand day
@joliet: What's up?
Read about the Slack API and then set up your own Slack team for testing purposes by going to slack.com and choosing the “Create a new team” option. Login to your test team and make a few posts.
To interact with your test team via the Slack API, you must 1) create a Slack app and install it in your workspace and 2) generate an authentication token. Follow the information here to do that.
Regarding Authentication: There are two types of OAuth tokens: Bot tokens and User tokens. You need to configure a User token, because Bot tokens will not allow your app to read the messages in channels. When configuring your token on the OAuth & Permissions page, configure the following User Token Scopes (make sure you’re not in the Bot Token Scopes section): channels:history, channels:read, chat:write, and users:read. After configuring the permissions, copy the OAuth Access Token and test it out by pasting it into the token argument on the users.list Tester form, which allows you to test the Slack users.list API. You will need to include this token with your request (see Authentication for details).
Next, spend some time exploring the Slack API Methods. Use the test interface to invoke the test methods from your browser. Use your browser’s developer tools to inspect the network traffic as you perform these tests. Explore using the conversations.list method to list the channels, chat.postMessage to post a message in a channel, conversations.history to retrieve posts made in a channel, and users.list to list the users.
Note that the Slack API has evolved over the years and in some cases there are multiple methods that can perform some of these tasks. I recommend the ones listed here for simplicity.
Next, write a test Node.js program that invokes the channels.list method and displays the id and name of each channel to work out the techniques you’ll need. Use the HTTP POST technique.
Implement the show-channels, show-users, and post commands.
Detect and handle errors gracefully.
In addition to the Max 75 Level, implement the get-posts command. When calling conversations.history, use a count of 5, and use the paging mechanism described in the API documentation for conversations.history to retrieve all of the messages.
Organize the code that communicates with the Slack service into an object-oriented module that defines a JavaScript “class” named Slack. Define the module in a file named slack-api.js in the same directory as slack.js, and require() it in your main program. See nodejs/module_demo_oo in the class files for a small example that demonstrates this organization.
Design your API with a separate method for each command listed above. Your API must be reusable; there should be no program-specific behavior in your slack-api.js file (i.e., console.log() should not be used in your API).
For example, to support the show-channels command, you might design a method getChannels() that pulls a list of channels from the Slack service, puts them into a list of objects, and returns them to the caller, which might invoke the method like this:
slack = require('./slack-api');
var s = new slack.Slack();
s.getChannels(function(err, channels) {
if (err) { /* handle error */ }
// display results
var channel;
for (channel in channels) {
console.log(channel.name + " " + channel.topic);
}
});
Read about promises and async/await in these tutorials:
Then, write a separate version of your program that uses promises or async/await to improve your code in the following ways:
Call these file versions slack-xc.js and slack-api-xc.js.
See the course syllabus for grading criteria.
Clone your submission repository using the link at the top of this page.
Submit slack.js (and slack-api.js, if you did it) electronically
Create a report following these instructions. Provide screen shots in the Official Tests section demonstrating that your program works. Include a couple of error handling scenarios. Save your report as report.pdf and upload electronically.