tests/cases/conformance/expressions/functions/contextuallyTypedIifeStrict.ts(14,10): error TS18048: 'j' is possibly 'undefined'.
tests/cases/conformance/expressions/functions/contextuallyTypedIifeStrict.ts(15,10): error TS18048: 'k' is possibly 'undefined'.
tests/cases/conformance/expressions/functions/contextuallyTypedIifeStrict.ts(16,17): error TS18048: 'o' is possibly 'undefined'.


==== tests/cases/conformance/expressions/functions/contextuallyTypedIifeStrict.ts (3 errors) ====
    // arrow
    (jake => { })("build");
    // function expression
    (function (cats) { })("lol");
    // Lots of Irritating Superfluous Parentheses
    (function (x) { } ("!"));
    ((((function (y) { }))))("-");
    // multiple arguments
    ((a, b, c) => { })("foo", 101, false);
    // default parameters
    ((m = 10) => m + 1)(12);
    ((n = 10) => n + 1)();
    // optional parameters
    ((j?) => j + 1)(12);
             ~
!!! error TS18048: 'j' is possibly 'undefined'.
    ((k?) => k + 1)();
             ~
!!! error TS18048: 'k' is possibly 'undefined'.
    ((l, o?) => l + o)(12); // o should be any
                    ~
!!! error TS18048: 'o' is possibly 'undefined'.
    // rest parameters
    ((...numbers) => numbers.every(n => n > 0))(5,6,7);
    ((...mixed) => mixed.every(n => !!n))(5,'oops','oh no');
    ((...noNumbers) => noNumbers.some(n => n > 0))();
    ((first, ...rest) => first ? [] : rest.map(n => n > 0))(8,9,10);
    // destructuring parameters (with defaults too!)
    (({ q }) => q)({ q : 13 });
    (({ p = 14 }) => p)({ p : 15 });
    (({ r = 17 } = { r: 18 }) => r)({r : 19});
    (({ u = 22 } = { u: 23 }) => u)();
    // contextually typed parameters.
    let twelve = (f => f(12))(i => i);
    let eleven = (o => o.a(11))({ a: function(n) { return n; } });
    // missing arguments
    (function(x, undefined) { return x; })(42);
    ((x, y, z) => 42)();