- An empty `[]` whose own type is `never[]` (a `return []` in an async
function, whose contextual type is `T[] | PromiseLike<T[]>`, or an
object literal's `files: []` field) builds as the unit-only element
array, like the empty tuple, so typed array slots receive it through
the checked empty-array lift. It was `number[]`, so `string[]` slots
refused it with SC1090 or SC2002.
- The refusal "instanceof against this native constructor" names its
site, and coverage lists the sites whose right-hand side is `Object` or
`Function`, which always reach it. An arrow function or method on the
right of an untyped `instanceof` throws Node's "Function has non-object
prototype" TypeError for an object.
- Coverage lists the diagnostics of a function whose signature did not
compile. A use of a parameter whose type did not compile reports SC2004.
- Coverage lists deferred fences in a module's top-level code under "runs
at startup", and the diagnostics envelope marks them `startup: true`.
Chris Tate
aeb429c066