README

Basic test assertions expect(...)->toEqual('valid').

This package replaces and is inspired by fbexpect.

Usage

You pass the expression under test to expect(...) as the first argument. The returned object exposes some common assertions you'd want to make about a value, such as ->toEqual(). The simplest test you could write is:

expect(1 + 1)->toEqual(2);

Customization

Use the BasicAssertions trait to add assertions specific to your project. Implement getValue(), plus the trait's protected getThrown() and withValue() methods. This example asserts that a numeric value is positive:

namespace MyProject\Tests;

use namespace HTL\Expect;
use type Throwable;

final class MyAssertions<T> {
  use Expect\BasicAssertions<T>;

  public function __construct(private T $value)[] {}

  <<__Override>>
  public function getValue()[]: T {
    return $this->value;
  }

  <<__Override>>
  protected function getThrown()[]: ?Throwable {
    // This example wraps values, so it has no captured invocation failure.
    return null;
  }

  <<__Override>>
  protected function withValue<Tvalue>(Tvalue $value)[]: MyAssertions<Tvalue> {
    return new MyAssertions($value);
  }

  public function toBePositive()[]: this where T as num {
    return $this->toBeGreaterThan(0);
  }
}

function expect<T>(T $value)[]: MyAssertions<T> {
  return new MyAssertions($value);
}