expect-helpers.ts

import { protractor } from 'protractor/built/ptor';
import { from, interval, of } from 'rxjs';
import { map, mergeMap, takeWhile } from 'rxjs/operators';

const EC = protractor.ExpectedConditions;

/*
  This is used for evaluation an expression up to x times with y timeout per try
  Use this to fix fragile expects
*/
export class ExpectHelper {
  public static async expectOrRetry<T>(
    expectFunc: () => Promise<boolean>,
    timeout: number = 5000,
    tryCount: number = 60
  ): Promise<any> {
    try {
      const res = await expectFunc();
      if (!res) {
        throw new Error('Evaluation is false.');
      }
    } catch (error) {
      if (tryCount > 0) {
        browser.sleep(timeout);
        console.log(
          `Expression failed, retries left: ${tryCount} on expression ${expectFunc.toString()}`
        );
        tryCount = tryCount - 1;
        this.expectOrRetry(expectFunc, timeout, tryCount);
      } else {
        // tslint:disable-next-line:no-console
        console.error(`Error while evaluating expression on ${expectFunc.toString()}`);
        throw error;
      }
    }
  }
}