Add lint rule against unnamed default exports

[gaearon]

We should add https://github.com/benmosher/eslint-plugin-import/blob/master/docs/rules/no-anonymous-default-export.md to our rule set. Warning level.

[shakib609]

I would like to work on this issue.
Can I be assigned to this if it's is up for grabs?

[gaearon]

Sure.

[overfuse]

Would it show warnings for default exports with HOC like React.memo(Foo) as well?

[shakib609]

Would it show warnings for default exports with HOC like React.memo(Foo) as well?

No, it's disabled by default.
These are the default settings

{
  "allowArray": false,
  "allowArrowFunction": false,
  "allowAnonymousClass": false,
  "allowAnonymousFunction": false,
  "allowCallExpression": true, // The true value here is for backward compatibility
  "allowLiteral": false,
  "allowObject": false
}

The allowCallExpression is the case you're referring to.

[millermedeiros]

FYI, I created a jscodeshift codemod script to add names to unnamed default exports: https://astexplorer.net/#/gist/28db7eb6dccb39dd388c030ca75b5de8 — it uses the file name and/or folder name as the function/variable name, and avoids name conflicts... — I used it today to process a few thousand JS files and it worked really well, YMMV tho...

# convert all the files inside the "src" folder
jscodeshift -t ~/Desktop/named-exports-codemod.js src

# open all the files that had name conflicts inside vim
git diff --name-only | xargs grep -l 'FIXME: identifier' | xargs -o vim

# run prettier on all the edited files
git diff --name-only | xargs prettier --write