Only display user-defined JS lint errors

[vicnicius]

Describe the bug
Based on #345.

Wasp should only inform users of lint errors they can address. Currently, it also warns about errors in the generated files.

For example, this is the current output of running the Todo tutorial code:

Notice the warnings regarding the /src/auth/* JS (generated) files.

[Martinsos]

Awesome, thanks @vicnicius !

To solve this, we should ensure that linter lints only files present in ext-src/ in the generated project, since everything else is generated code.
I am guessing this can be done by modifying the linter configuration (although I am not sure where would that be) on both frontend and backend. We should investigate how that can be done in regards to how we are building projects right now.

[vicnicius]

My pleasure, @Martinsos. Yes, you could probably update the web-app template to also output a .eslintignore configuration. Alternatively, maybe it would make sense for wasp to simply add a [/* eslint-disable */](https://eslint.org/docs/2.13.1/user-guide/configuring#disabling-rules-with-inline-comments) to the top of every generated file. Not sure what you would find best.

Also, on the topic of code styles, later on, wasp could provide a way for users to use a specific format for the generated code. Maybe something like:

client {
  format: 'prettier' // or eslint, or tslint, etc...
}

[Martinsos]

@vicnicius that sounds good, any of those approaches sounds reasonable! Maybe central configuration like .eslintignore would be easier to maintain / work with, but let's see.

Interesting idea about providing a way to specify the formatter, we should look into that at some point for sure.

[makinox]

Hello, any problem if I work on this?

My plan

• Add the rule in the generated package.json to ignore ESLint messages in the .wasp/out folder

I would love to implement .eslintignore but that would require more planning with you and install an additional library to extend configurations

[sodic]

@makinox Hey, sorry for the late reply.

No problem at all, quite the opposite :)

I like the approach and I've reviewed your PR. Let me know what you think.

[programmersoham]

Is this still open ?

[Martinsos]

Is this still open ?

Yes, it still is! Go for it if you want!