feat: upgrade to Angular 13 in order to support recent move to Ivy

[maxime1992]

Summary

• Upgrade to Angular 13 so that consumers don't have to run ngcc anymore on that lib
• Remove TSLint as it's deprecated and setup ESLint instead

This PR fixes/implements the following bugs/features

• [x] #390
• [x] Breaking changes: I'd consider that a breaking change (and made a commit accordingly) as we're bumping to a new major version of Angular

Explain the motivation for making this change. What existing problem does the pull request solve?

Apps running on Angular 13 get a warning asking to update this lib as on next version of Angular, view engine support will be dropped and this library couldn't be used anymore

Requirements

Make sure these boxes are checked:

• [x] link to an issue
• [x] tests are updated (added/changed/removed)
• [ ] tests run successfully (local)
• [ ] tests run successfully (TravisCI)
• [ ] please follow this styleguide for this pr title

[orizens]

@maxime1992 thanks. i started work on migrating the project to use angular library format https://angular.io/guide/creating-libraries would appreciate your support when i publish the branch before merging to master.

[maxime1992]

Hello.

Damn :sweat: bad timing I just spent an hour on this. Anyway nice one!

Indeed it's definitely better to follow this I just assumed you had a strong preference with the current setup.

If not one thing I'd suggest would be to create a new angular cli project from scratch where you:

• name the app ngx-infinite-scroll-demo when the CLI asks you how to name the workspace
• then create a project that you call ngx-infinite-scroll which will be the library to publish

We've been doing that pattern on several repos (ngx-favicon, observable-webworker, ngx-observable-lifecycle, ngx-sub-form, ...) and it works really well. You can develop your library and have a test/demo app that is published on github page as well for example.

Also gives the benefit of making the upgrade process much smoother as it currently is.

I'll leave you to it then and close that MR. Good luck on your branch and feel free to ping me once you've got something ready :+1:

[orizens]

@maxime1992 v13 has been release to the main master branch. please feel free to take a look, enhance and open a pr.