SampleCheck.ts

import {Context} from 'probot/lib/context';

import {ChecksUpdateParamsOutput} from '@octokit/rest';
import {WebhookPayloadPullRequest} from '@octokit/webhooks';

import CheckRun, {ICheckRun} from './CheckRun';

export default class SampleCheck extends CheckRun implements ICheckRun {
  static checkName: string = 'my-cool-check';
  public payload: WebhookPayloadPullRequest;

  constructor(event: Context) {
    super(SampleCheck.checkName, event);
    this.payload = event.payload;
  }

  async run(): Promise<void> {
    const output: ChecksUpdateParamsOutput = {summary: ''}; // The API requires a summary no matter the outcome

    // Updates the GitHub UI to switch the status from "queued" to "in progress"
    await this.update('in_progress');

    // Do some sort of business logic here. For this example, we'll randomly pass or fail
    const success = Math.random() >= 0.5;

    if (!success) {
      output.title = 'Failed coin toss'
      output.summary = 'Luck is not on your side today, you failed to be pass the test.'
    }

    await this.finish(success, output);
  }
}