Drop non-working default export for TypeScript users

[fregante]

Fixes #88

I kept the TODO like in https://github.com/sindresorhus/mem/blob/10f13c0904e497a35bb4cba907490aad1ba6d879/index.d.ts#L93

[fregante]

I'm not entirely sure of how to fool import/default without having an actual export default

See eslint's log at https://travis-ci.org/sindresorhus/is/jobs/533220117

[sindresorhus]

I would prefer just reverting back to:

export default is;

// For CommonJS default export support
module.exports = is;
module.exports.default = is;

Which we know are working.

[fregante]

export default is isn't right? sindresorhus/memoize#31

[sindresorhus]

Not exactly, since the source here is TypeScript, while sindresorhus/memoize#31 is about CommonJS.

[fregante]

The previous change broke compatibility (sadly, but we’re still v0.x) but given the TODO comment in that PR, I think your modules aren’t meant to export default in the first place.

is is still a CJS module and thus it should not be imported via import is from x in TypeScript, especially with esModuleInterop disabled 🤷‍♂️

[sindresorhus]

You have to update the test to use import is = require('.') syntax.

[fregante]

Either import/default follows esModuleInterop and therefore allows import X from Y on CJS modules, or @typescript-eslint/no-require-imports should be disabled.

Since I have to disable a rule, I might as well leave the old ESM import and disable import/default on that line

[fregante]

The last two commits are valid but there's an unrelated TS issue:

  Uncaught exception in test/test.ts
  test/test.ts:30:13 - error TS2749: 'TypeName' refers to a value, but is being used as a type here.
  
  30  typename?: TypeName;
                 ~~~~~~~~

[sindresorhus]

Fixing this properly requires too many breaking changes. We'll also have to put every type export behind a namespace. I'm just gonna revert the original commit and keep it like this until we can move to ESM later this year.