=== tests/cases/compiler/numberOnLeftSideOfInExpression.ts ===
var left: number;
>left : number, Symbol(left, Decl(numberOnLeftSideOfInExpression.ts, 0, 3))

var right: any;
>right : any, Symbol(right, Decl(numberOnLeftSideOfInExpression.ts, 1, 3))

left in right;
>left in right : boolean
>left : number, Symbol(left, Decl(numberOnLeftSideOfInExpression.ts, 0, 3))
>right : any, Symbol(right, Decl(numberOnLeftSideOfInExpression.ts, 1, 3))