fix: update performance when used with other preset

[mathieumure]

Fix #92

I figured out that passing typescript module in settings is too heavy and produces overhead in other preset such as eslint-config-airbnb-base.

In this PR, I load typescript only once to avoid overhead.

[dummdidumm]

This should be a backwards compatible change to not break existing users, so it would need to check if a boolean was passed in. Also I don't like that now there's a require of TypeScript inside the code base, the API was designed that way to avoid that. I instead suggest something like 'svelte3/typescript': () => require('typescript') which would also achieve the lazy loading behavior you are looking for.

The other thing is I don't quite understand how this will help performance. If you use TypeScript, it will be used either way at some point, so if you pay the cost upfront or later on shouldn't matter right?

[Conduitry]

I skimmed @dummdidumm's comment, and then was about to say "If we have to lazy load, I'd much prefer something like () => require('typescript') where it remains the config file's responsibility to do the loading" and then I saw that that is exactly what he suggested.

I too am confused about where the overhead would be coming from here. Can you explain more what's going on? Is the config file re-evaluated (without a require cache) a bunch of times for different plugins?

[mathieumure]

Hello @Conduitry and @dummdidumm,

Thanks for the quick reply 👍
You are right and I just realized that my code is not backward compatible after creating the PR 😅
I just correct accordingly to your suggestions.

I'm still trying to figure out what are the rules slowing down by this setting.
My guess is that some rule recursively runs through all keys in settings and the `require('typescript') is really big.
So far, I find that it's linked to import related rules but I don't have the reason why.

[dummdidumm]

In #95 it came up to do the true option like you initially proposed. In that issue @Conduitry seemed to be okay now with going that route after checking back with the eslint maintainers. If he confirms, then you could switch back the implementation to the first one. Sorry for the back and forth 😅

[mathieumure]

@dummdidumm ha ha ha ok. I'll do it when @Conduitry will confirm it 😉.

[mathieumure]

@dummdidumm I add a boolean option with the functional one. Tell if you are okay with this.

[JounQin]

@dummdidumm I add a boolean option with the functional one. Tell if you are okay with this.

Or add string option too?

[mathieumure]

@dummdidumm I add a boolean option with the functional one. Tell if you are okay with this.

Or add string option too?

What do you intend to do with this string ? 🤔 Do you have any use case ?

[JounQin]

@mathieumure I want to use ttypescript instead.

[mathieumure]

@JounQin 🤔 I think we can achieve this in another PR because IMO it's a new feature.

[mathieumure]

@Conduitry did you have the time to check this PR ?

[Conduitry]

This has been released (with some adjustments in) 3.2.0. Thank you!