Located potential errors resulting from misspellings of variable and parameter names, or accidental implicit globals.
var a = b; // b is not defined.
function f(a: Foo) {
// `Foo` is not defined
}
var a: AType
// Additional rules: {"no-undef":2}
var a: AType; var b: AType
// Additional rules: {"no-undef":2}
var a; (a: AType)
// Additional rules: {"no-undef":2}
var a: AType<BType>
// Additional rules: {"no-undef":2}