Mocking formatDate

[dargmuesli]

Hey there, before upgrading to v2 I want to add a test that asserts nothing breaks.
My issue is that the DTSTAMP is dynamically generated, so I cannot check for a static result. I first think of mocking the function, which provides the fields value to receive a predictable result:

ical-generator/src/event.ts

Line 1348 in ac05fb6

g += 'DTSTAMP:' + formatDate(this.calendar.timezone(), this.data.stamp) + '\r\n';

But formatDate is not exported on the library level. How can I go about this then? Could we add it as exported member or is there a better way to do it?

[sebbo2002]

🎉 This issue has been resolved in version 2.1.0-develop.1 🎉

The release is available on:

• npm package (@next dist-tag)
• GitHub release
• v2.1.0-develop.1

Your semantic-release bot 📦🚀

[dargmuesli]

🎉

[dargmuesli]

Well, me is very sad and frustrated. Looks like jestjs/jest#936 explains that it isn't really possible to replace transitive function calls. I've now spent way too many hours trying to work my way around it, but it doesn't really seem possible. There are babel-powered solutions like https://github.com/speedskater/babel-plugin-rewire, but I don't get why I'd need to use extensive transpilation and that typescript doesn't offer this functionality itself.

Solutions like this: https://stackoverflow.com/a/47976589/4682621
Or these: greeting.exports.js, greeting.dependency-injection.js
But as far as I see, those won't solve the issue in this case? Hmm, I don't really know. Either way, I've already spent way too many hours on this. But I'd be very glad if you'd give your opinion on this. Until then, I already want to thank you for your great support!

[dargmuesli]

Oh my,

beforeAll(() => {
  jest.useFakeTimers('modern')
  jest.setSystemTime(new Date(0))
})

afterAll(() => {
  jest.useRealTimers()
})

just saved my well being. Sniff.
It mocks the environment time so I can simply check for 19700101T010000 or similar.

[sebbo2002]

🎉 This issue has been resolved in version 2.1.0 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release
• v2.1.0

Your semantic-release bot 📦🚀