02/04 - Mocked date gives wrong day if time not explicitly set to be after 00:00

[isimmons]

In exercise 02 section 04 "Hooks" my test failed. When mocking the date it appears to be defaulting to "2024-01-01:00:00" but the day doesn't actually start until 1 second after that so what I get is "2023-12-31" if I console.log it out.

I fixed it in my code by explicitly setting the time to 1AM

beforeAll(() => {
	globalThis.Date = new Proxy(globalThis.Date, {
		construct: () => new OriginalDate('2024-01-01:01:00'),
	})
})

I just realized this is a problem on every lesson after this one. Is it something wrong on my end?

Windows 10, node 20

[kettanaito]

Hi, @isimmons. Thanks for sharing this!

I've encountered a similar issue when giving the live version of this workshop, where the culprit was the omission of the explicit locale when calling .toLocaleDateString(). I've then defaulted it to en-US, which should produce the same date for everyone:

testing-fundamentals/exercises/02.test-structure/04.solution.hooks/greet.ts

Line 2 in 753655b

const weekday = new Date().toLocaleDateString('en-US', { weekday: 'long' })

I'm trying to reproduce your issue, this is where I got:

--- a/exercises/02.test-structure/04.solution.hooks/greet.test.ts
+++ b/exercises/02.test-structure/04.solution.hooks/greet.test.ts
@@ -6,6 +6,8 @@ beforeAll(() => {
        globalThis.Date = new Proxy(globalThis.Date, {
                construct: () => new OriginalDate('2024-01-01'),
        })
+
+       console.log(new OriginalDate('2024-01-01'))
 })
 
 afterAll(() => {

This prints the following for me:

2024-01-01T00:00:00.000Z

Does this print 2023-12-31 for you?

[isimmons]

Yes Sir, here is my output.

    const date = new OriginalDate('2024-01-01')
    console.log(date) // 2024-01-01T00:00:00.000Z
    console.log(date.toLocaleDateString()) // 12/31/2023
    console.log(date.toLocaleDateString('en-US', { weekday: 'long' })) // Sunday

    const anotherDate = new OriginalDate('2024-01-01:00:00:00.001')
    console.log(anotherDate) // 2024-01-01T00:00:00.001Z
    console.log(anotherDate.toLocaleDateString()) // 1/1/2024
    console.log(anotherDate.toLocaleDateString('en-US', { weekday: 'long' })) // Monday