Here is the titular Twitter bot.
Its daily mission : To recount what happened in history on that particular day.

For example on Nov 22, 2021 The bot tweeted a historical event that took place on Nov 22

235 : Pope Anterus succeeds Pontian as the nineteenth pope. During the persecutions of emperor Maximinus Thrax he is martyred. https://t.co/eecbAnRmCZ

— OnceUponThisDay (@jayanthisabot) November 21, 2021

Concept

The idea is very simple, steps involved would be

1. Get current date
2. Get some historical event for that date: Wikipedia is a great source as you can search for a day and get all events for that day eg : November 22
3. Tweet it!!

My task was made easy thanks to two wonderful npm packages

wtf_wikipedia : Library to parse data from wikipedia

Twit : Twitter API Client for node, Supports both the REST and Streaming API.

Using these libraries the idea was to create a NodeJS app and host in publicly.

Implementation

Getting data from Wikipedia

Once I had the current date, I formatted it as required by Wikipedia search

function getFormattedDate() {
    const date = new Date();
    const month = date.toLocaleString('default', { month: 'long' });
    const day = date.getDate();
    return month + '_' + day;
}

Once the date is created I can use the wtf_wikipedia to get the details of the page.

 const doc = await wtf.fetch(date, 'en');
 const data = doc.json()

Seeing the structure of the page, I would like to exclude Deaths and Births data and only stick to Events

Poking around the json data, I decided to filter out the data as follows

 for (let i = 0; i < data.sections.length; i++) {
        if (data.sections[i].title.toLowerCase() === 'deaths' || data.sections[i].title.toLowerCase() === 'births') {
            break;
        }
        if (data.sections[i].title && data.sections[i].title.toLowerCase() !== 'events') {
            events.push(data.sections[i])
        }
    }

Now it is just matter of selecting one of the events by random from the events list.
Some cleaning and formatting I finally have the link to tweet.

    const randomSectionList = events[randomNumber(0, events.length)].lists[0]
    const randomListItem = randomSectionList[randomNumber(0, randomSectionList.length)]
    const page = randomListItem.links[randomListItem.links.length - 1].page
    const pageLink = ` https://en.wikipedia.org/wiki/${page.replace(/ /g, "_")}`

    const tweet = randomListItem.text.replace("–", ":") + pageLink

Tweeting the event

Twit is a powerful library, I should probably use its other streaming features in future project, for now let's stick to the basics and just use the tweet functionality.

Initial configuration would require some keys and tokens to be set in .env file

CONSUMER_KEY=<CONSUMER_KEY>
CONSUMER_SECRET=<CONSUMER_KEY>
ACCESS_TOKEN=<ACCESS_TOKEN>
ACCESS_TOKEN_SECRET=<ACCESS_TOKEN_SECRET>

These keys can be got from the Twitter developer console

More on developer account

Now lets tweet

const T = new Twit(config);
T.post('statuses/update', { status: tweet }, function (err, data) {
     if (!err) {
        console.log("Tweeted", data.text)
     }
})

That's it!! the bot has searched for events in Wikipedia and tweeted. Now just matter of enclosing these functions in an interval so that the actions are repeated.

I set it tweet every 12 hours

setInterval(getRandomWiki, 1000 * 60 * 60 * 12)

I hosted the app on Heroku.
You can find the hosting details here

Now you have a bot that tweets daily about random events of the past.

You can find the full code here

Cover Photo by Aron Visuals on Unsplash