Adding cron jobs support

[omarkhairy21]

Hey, @jplhomer thanks for that awesome work i was struggling to build my abstraction around the Cloudflare stack but you did an amazing job!

I am wondering if there is a plan to support Cron jobs. Also, i am ready to contribute to this.

[jplhomer]

I would love this!

• I would aim to design it like Laravel's task scheduling but probably with a smaller list of possible values
• The main value prop is that you don't have to reason about cron expressions at all to use it
• The dev would simply set the cron value in wrangler.json to run every minute, and Superflare's cron handler would attempt to match against the current date.

One challenge:

• Existing Cron expression parsers/matchers tend to be very heavy and rely on large 3p datetime deps. Would be great to find either a small one with no deps, or build our own modeled after e.g. https://github.com/datasert/cronjs

Proposed API

// worker.ts

export default {
  async scheduled(event: ScheduledEvent, env: Env, ctx: ExecutionContext) {
    await handleScheduled(event, env, ctx, (schedule: Schedule) => {
      schedule.run(async () => {
        // some bespoke function
      }).dailyAt('8:00').timezone('America/New_York');

      schedule.job(new MyJobClass(my, args)).weekly();

      // ...
    });
  },
}

[jplhomer]

How does this sound? https://github.com/jplhomer/superflare/issues/18

[omarkhairy21]

Sounds Great! thanks for that huge effort I left a comment with just one concern on the pull request

[omarkhairy21]

BTW that pull request and your comment inspired me to create a cron toolkit library to create cron expressions with human-readable functions also with type safety

[jplhomer]

@omarkhairy21 That's awesome!