There are a few problems in TypeScript that limit the expressiveness of the type declarations. This page tracks the known issues that we submitted or found on the TypeScript codeplex bugtracker.
If you know of a typing related issue not linked here please leave and issue in this repos or make a PR on the source-branch.
Get/set accessors in interfaces
Allow to extend global variables like Date or Object to support libs like sugar.js
Use Static interfaces for ambient declarations in lib.d.ts
Support optional ambient "this" pointer typing in callback/function signatures
declaring callback scope members
Allow additional parameters after ..rest in declarations
Add support for type unions
declarations cannot describe function 'try' on module
decaring types for array-based tuples
Cleanup or select lib.d.ts global namespace
export =not usable without claiming a name in the global namespace
Allow operators to work on custom types (via valueOf)