Destructured Typing with variables after a rest elements

[tlgreg]

When destructured typing is used with rest elements in the middle, the last variable is not typed currently (0.11.0)

This for example can cause a TS error when the number of elements does not match in tuple types.

Input

[first:: string, ...rest:: number[], last:: string] := list

Expected Output

const [first, ...rest]: [string, ...number[], string] =
    list,
  [last] = rest.splice(-1);

Current Output

const [first, ...rest]: [string, ...number[]] =
    list,
  [last] = rest.splice(-1);

Notes about types

In the above example rest becomes [...number[], string] — essentially equals to (string | number)[] instead of number[] — and last will be string | number | undefined.

Meaning typing last will not just be incorrect itself, but also screw up the types for rest too.

TS itself is problematic with extracting the types from tuples like this.