Could you reconsider the "tsconfig.json" default value of "strict: false"?

Feature request

I just noticed that next.js defaults to strict: false in the generated tsconfig.json.

The reasoning behind seems to be (quoting @Timer from ##7716):

Users who are testing out Next.js’ TypeScript support shouldn’t be stuck behind a failure to compile screen. This will allow advanced users to opt into strict: true when they’re ready.

I would ask you if it were possible to reconsider this.

Running tsc --init creates a tsconfig.json with strict: true since that option was introduced with TypeScript 2.3. An advanced user will probably not notice this for quite some time, because they assume that TypeScript offers it’s full (default-configuration) functionality out of the box, just wondering about unsound behaviour here and there until it piles up and finally going to strict: true has actually become a chore.

If there are any strict options that are not working well with next.js, it’s still an option, to default to strict: true in combination with strictThatHurts: false and mentioning to that in the documentation.

I have to admit that I’m not even a next.js user myself (athough it is in my list of stuff to check out!), but got a report by a user of our library (@reduxjs/toolkit) about strange behaviour - which we could attribute back to strictNullChecks being disabled. The user was quite irritated because they had assumed that strict would be enabled.

So I don’t really believe that you’re doing your users a service with this default 😦

As an alternative, if you could not commit to a strict: true default, maybe it might be an option to actively ask the user for feedback on it when the tsconfig.json would be filled with the default values - and let the user decide between “loose” and “strict” behaviour?

[tanvp112]

User assumption is not the responsibility of the framework, I supposed. Note typescript is not perfect, the trans-piled code sometimes can cause unexpected behavior, too.

I think the default should stay as false. User can change to true anytime as they see fit. Or better, checkout https://github.com/facebook/prop-types

[filipesmedeiros]

hey team, love the work. since a flag --typescript / -ts was added for the next-app cli, is there any chance this config should be changed to match that one? (that currently enforces strict by default)?