@thisisagile/easy-test/src/matchers/Check.ts

Straightforward library for testing microservices built with @thisisagile/easy

import { isDefined } from '../utils/Utils';

type ToMessage<S> = string | ((s: S[]) => string);

class Check<S> {
  constructor(
    private ctx: jest.MatcherContext,
    private readonly received: S,
    private readonly expected: S,
    private readonly failed = false,
    private readonly message = ''
  ) {}

  print(message: ToMessage<S>): string {
    return (typeof message === 'function' ? message([this.received, this.expected]) : message)
      .replace('{r}', this.ctx.utils.printReceived(this.received))
      .replace('{e}', this.ctx.utils.printExpected(this.expected))
      .replace('{diff}', this.ctx.utils.diff(this.received, this.expected) ?? '');
  }

  not(p: (s: S[]) => boolean, message: ToMessage<S>): Check<S> {
    if (this.failed) {
      return this;
    }
    try {
      return new Check<S>(this.ctx, this.received, this.expected, !p([this.received, this.expected]), this.print(message));
    } catch (e: any) {
      return new Check<S>(this.ctx, this.received, this.expected, true, e.message);
    }
  }

  undefined(p: (s: S[]) => any, message: ToMessage<S>): Check<S> {
    return this.not(() => isDefined(p([this.received, this.expected])), this.print(message));
  }

  else(message: ToMessage<S> = 'Expected {r} not to match with {e}, but it did.'): jest.CustomMatcherResult {
    return {
      pass: !this.failed,
      message: () => (this.failed ? this.message : this.print(message)),
    };
  }
}

export const check = <S>(ctx: jest.MatcherContext, received: S, expected?: S): Check<S> => new Check<S>(ctx, received, expected as S);

export const checkDefined = <S>(ctx: jest.MatcherContext, received: S, expected?: S): Check<S> =>
  new Check<S>(ctx, received, expected as S).undefined(([r]) => r, 'Received array is undefined.').undefined(([, e]) => e, 'Expected array is undefined.');