Fix undefined bug for template strings.

[beefancohen]

Fixes #40

cc: @AlmeroSteyn is this the expectation?

[coveralls]

Coverage remained the same at 98.795% when pulling d77e0ad on fix-template-literal into c055fab on master.

[ljharb]

Yes, this is correct- template literals always toString directly, and null and undefined toString to "null" and "undefined" respectively.

[AlmeroSteyn]

@evcohen Thank you!

template literals always toString directly, and null and undefined toString to "null" and "undefined" respectively.

The issue only pertained to undefined which now works perfectly as expected.

But if I apply the fix in my fork and run with null it still returns an empty string instead of "null".

Separate issue?

[ljharb]

This should check for both "undefined" or "null", perhaps?

[AlmeroSteyn]

I initially tried this myself but for null the part.name is actually undefined and the part.value.raw throws a TypeError so it seems that something is happening higher up already.

[beefancohen]

uh oh it looks like this may have been a breaking change. eslint-plugin-jsx-a11y tests are failing on v2.1.0

[ljharb]

Which tests? Is it possible the tests were incorrect?

[beefancohen]

Yes that looks to be the case. Fixing now