TypeScript Version: 2.1.4

(0,eval)('var x = 10');

Expected behavior:
Compile fine.

Actual behavior:
error TS2695: Left side of comma operator is unused and has no side effects.

See also at TS Playground.

(0,eval) is a well-used convenience syntax for invoking eval with a global scope (as opposed to the scope of the caller).

One possible workaround is: (eval||null). But that's longer and most of all — hard to Google the reasoning behind. Whereas (0,eval) is easy to find a detailed explanation for.

Please make it not error.