tests/cases/compiler/literals-negative.ts(5,9): error TS2352: Neither type 'number' nor type 'boolean' is assignable to the other. ==== tests/cases/compiler/literals-negative.ts (1 errors) ==== // Type type of the null literal is the Null type. // Null can be converted to anything except Void var n = (null); var s = (null); var b = (n); ~~~~~~~~~~~~ !!! error TS2352: Neither type 'number' nor type 'boolean' is assignable to the other. function isVoid() : void { } // Expected error: Values of type null and void cannot be compared if(null === isVoid()) { }