[New] import/default: support default export in TSExportAssignment

[Maxim-Mazurok]

Possible duplicate of #1528 (but uses tsconfig.json)
Aims to fix #1527

For example, I want to import React as import React from "react". I can do this by using esModuleInterop: true in tsconfig.json, but eslint doesn't know about that.

This is a draft PR as I'm not really familiar with the codebase. I want to share my approach and receive feedback.

[coveralls]

Coverage decreased (-0.03%) to 97.708% when pulling 0b585a1 on Maxim-Mazurok:master into 0547c7e on benmosher:master.

[coveralls]

Coverage decreased (-0.08%) to 97.715% when pulling 80f1a66 on Maxim-Mazurok:master into 1a3a128 on benmosher:master.

[coveralls]

Coverage decreased (-0.08%) to 97.715% when pulling 80f1a66 on Maxim-Mazurok:master into 1a3a128 on benmosher:master.

[coveralls]

Coverage decreased (-0.08%) to 97.715% when pulling 80f1a66 on Maxim-Mazurok:master into 1a3a128 on benmosher:master.

[coveralls]

Coverage decreased (-0.08%) to 97.715% when pulling 80f1a66 on Maxim-Mazurok:master into 1a3a128 on benmosher:master.

[coveralls]

Coverage decreased (-0.08%) to 97.715% when pulling 80f1a66 on Maxim-Mazurok:master into 1a3a128 on benmosher:master.

[coveralls]

Coverage decreased (-0.08%) to 97.715% when pulling 80f1a66 on Maxim-Mazurok:master into 1a3a128 on benmosher:master.

[ljharb]

@Maxim-Mazurok this seems fine, but is hard to review without tests. Could you add some?

[Maxim-Mazurok]

Sure, @ljharb, I will first test if #1527 was actually resolved and then will add some tests.
Also, as I've mentioned here that we should consider the case when there are multiple tsconfig.json files. Anyway, supporting one root config would be a good starting point, I think.

[Maxim-Mazurok]

@ljharb, I've created reproduction repo: https://github.com/Maxim-Mazurok/eslint-plugin-import-1689-reproduction

The issue is still present in 2.20.2 and on master branch.

[ljharb]

Thanks for confirming. I'd love to review and land this PR; could you modify your repro case to tests in this repo?

[Maxim-Mazurok]

Sure, creating a repro was the first step :) Now I'm going to add tests.

[Maxim-Mazurok]

@ljharb I fixed my code and added tests, please, take a look.
I also had to fix import ReactDOM from 'react-dom'; case in my last commit to make it work on real-world app, where you import both React and ReactDOM.

[ljharb]

We have array-includes for includes already; and i added a try/catch around the JSON.parse just in case, and i rebased it.

See comments, tho.

[Maxim-Mazurok]

@ljharb thanks for your comments and fixes. I added fix for JSON.parse. Please, don't force-push your commits that overwrite my commits, because I have no visibility as to what was changed by you. I understand that I did more commits than necessary, but you can "squash and merge" at the end to fix this problem. Thanks :)

[ljharb]

@Maxim-Mazurok "squash and merge" is not viable - it leaves the PR ref cluttered with the old commits, and orphaned from the master branch.

I'm going to force push this one again before landing it; while you can uncheck the "allow edits" box to prevent me from doing that, that has the unfortunate consequence of meaning I'll never merge the PR on any repo I manage, so I hope you won't do that :-)

[Maxim-Mazurok]

Oh, right, I totally forgot that, now it makes sense :)

Thanks!

[ljharb]

Thank you for the PR!