More explicit assert with hamjest [this is a draft]

An undone blog post - More explicit assert with hamjest

  it('is true for a day that is a specialDay', () => {
    const isSpecialDay = specialDays()[2].isSpecialDay;
    assertThat(isSpecialDay, equalTo(true));
  });

  it('provides the special day\'s `name`', () => {
    const specialDay = specialDays()[2].specialDay;
    assertThat(specialDay, equalTo({ name: specialDayName }));
  });

vs.

  it('is true for a day that is a specialDay', () => {
    const day = specialDays()[2];
    assertThat(day, hasProperty('isSpecialDay', equalTo(true)));
  });

  it('provides the special day\'s `name`', () => {
    const day = specialDays()[2];
    assertThat(day, hasProperty('specialDay', equalTo({ name: specialDayName })));
  });

there is even a simple transformation in it

assertThat(isSpecialDay, equalTo(true));

transforms into

assertThat(day.isSpecialDay, equalTo(true));

makes it obvious, that when the lookup day.isSpecialDay fails we will get an error message like undefined does not equal to true :( so let's tranform it into

assertThat(day, hasProperty('isSpecialDay', equalTo(true)));

and we will get: day has no property isSpecialDay which should equal to true

You might say, that's two assertion in on test, but I am fine with that as long as the test reporter tells me all the things that are wrong. Otherwise I would have to figure out in which order to solve failing tests.