.toBe(true) or .toBeTruthy()

#javascript #testing #jest #tips

I was reviewing a feature on GitHub and noticed my colleague sometimes used .toBe(true) and other times .toBeTruthy(). This got me wondering, are they actually different? After a quick search, I found out they are – and it's all in their names 😅. In this post, I'll break down these two functions and how they're not quite the same

`.toBe(true)` - Strict Equality

.toBe(true) is used to test strict equality. It checks if the value being tested is exactly true.
This means that the test will only pass if the value is the Boolean primitive true.
It's similar to using === true

test('strict true check', () => {
  const value = true;
  expect(value).toBe(true); // Passes
});

`.toBeTruthy()` - Truthiness Check

.toBeTruthy(), on the other hand, tests for 'truthiness' rather than strict Boolean true.
A value is considered "truthy" if it translates to true when evaluated in a Boolean context.
This includes values like 1, 'non-empty string', {}, [], and obviously true itself.

test('truthiness check', () => {
  const number = 1;
  const string = 'hello';
  expect(number).toBeTruthy(); // Passes
  expect(string).toBeTruthy(); // Passes
});