keyof - fix LUAU_ASSERT when there's only one key entry

[karl-police]

Fixes #1387

Was suggested by @alexmccord

I changed singletons[0] to singletons.front(), unsure if that makes a huge difference, and then I added the rest of the things needed for the return type.

Maybe it's also the ideal location since doing it before looping through keys won't add the string into the type arena.

I put comments next to it based on how I thought it would make sense.

 

LUAU_ASSERT seems to trigger when there's only one entry being put inside a UnionType. It's as if it was put there for quality.

Allow edits by maintainers is enabled.

I tested this with a quick Unit Test something like

local test: keyof<typeof({a="test"})>

[andyfriesen]

Thanks!

Could you add a unit test to TypeFunction.test.cpp?

[karl-police]

Thanks!

Could you add a unit test to TypeFunction.test.cpp?

will do in a bit

[karl-police]

Thanks!

Could you add a unit test to TypeFunction.test.cpp?

it has been done