ufuzz failure

[alexlamsl]

// original code
// (beautified)
export var _calls_ = 10, a = 100, b = 10, c = 0;

function f0(b_2, bar) {
    function f1(Infinity_2) {}
    var a = f1(--b + -(("foo" > "object" != 3 > "undefined") + ((Infinity != "c") >>> ("bar" || -1))), 4);
    function f2(bar, a_2, undefined_1) {
        {
            L20689: for (var brake6 = 5; a++ + bar && brake6 > 0; --brake6) {
                return c = 1 + c, (c = c + 1, "number" << "object") || (-0 == 5) <= 4 << "foo";
            }
        }
        switch (a++ + delete b) {
          case --b + a++:
            if (--b + (1 === 1 ? a : b)) {
                c = c + 1;
            }
            break;

          default:
            for (var brake11 = 5; (c = c + 1) + 3 && brake11 > 0; --brake11) {
                try {
                    c = 1 + c, (-4 || 23..toString() || 23..toString() == 3) >= ("bar" ^ 5) * (-4 <= -3);
                } finally {
                }
            }

          case a++ + (b = a):
            switch (undefined_1 && typeof undefined_1.next == "function" && --_calls_ >= 0 && undefined_1.next((c = 1 + c, 
            (null < "a" ^ "foo" / /[a2][^e]+$/) + (("b" !== ([ , 0 ].length === 2)) + (NaN == 5))), "")) {
              case b++:
                c = 1 + c, ("function" === "foo") >>> (bar && (bar[c = 1 + c, (false > 2) >> ("bar" >>> undefined) <= ("function" == Infinity | -1 >>> -3)] += ([ , 0 ].length === 2) > 38..toString())) ^ (NaN | "c") & [] <= "foo";
                c = 1 + c, (true > -0) << (-0 && 38..toString()) >= (bar && (bar.done += (24..toString(), 
                Infinity) && 5 - 2));
                break;

              case a++ + [ (c = 1 + c, ({} ^ [ , 0 ].length === 2 || 22 < 22) << ("a" & 0, 
                23..toString() >> this)) ].null:
                c = 1 + c, ("foo" > -2) + (-0 != true) >= ([ , 0 ].length === 2 === 23..toString()) >> 3 / 1;
                break;

              case ((c = 1 + c, ([ , 0 ].length === 2) >= -0 != NaN * "foo", (bar && (bar.next |= true << NaN)) >= ({} >= NaN)) || a || 3).toString():
                c = 1 + c, (bar && (bar[(c = c + 1) + typeof (c = 1 + c, ("function" > -4) % ("function" !== "undefined") < ("bar" <= "" ^ "undefined" != "function"))] &= (a_2 /= "bar" <= -0, 
                false >> false))) << delete (4 ^ 22);
                c = 1 + c, undefined_1 && (undefined_1.get = Infinity >> undefined & [ , 0 ].length === 2 != "undefined" ^ "bar" <= this == (NaN !== []));
                break;

              case /[abc4]/g.exec(((c = 1 + c, ~(("c" ^ []) << "foo" / true)) || b || 5).toString()):
                c = 1 + c, (bar && (bar.in |= (22 ^ NaN) >> ("object" | -2))) > (5 % Infinity <= [] - 22);
                break;
            }
            break;

          case (c = c + 1) + typeof (a++ + /[abc4]/g.exec((bar || b || 5).toString())):
            var Infinity_2;
            break;
        }
        if ((c = c + 1) + b--) {
            return typeof bar_1;
        }
    }
    var await = f2([ , 0 ][1], (b_2 && typeof b_2.foo == "function" && --_calls_ >= 0 && b_2.foo({}) || 3).toString()[(c = c + 1) + -(("foo" || "object") - (0 ^ true) || ("object" & -1) * ("a" << 1))], --b + (b_2 && typeof b_2.null == "function" && --_calls_ >= 0 && ((c = c + 1) + (bar = function yield() {
        {
            var brake1 = 5;
            while ((c = 1 + c, (2 % 5 <= "b" >> 23..toString()) % ((5 != "c") > ([ , 0 ].length === 2 === -2))) && --brake1 > 0) {
                c = 1 + c, "b" - this == -0 * Infinity & false >> "object" <= (c = c + 1, 
                /[a2][^e]+$/);
            }
        }
        switch (c = 1 + c, ("function" == -5 ^ (a = Infinity < 24..toString())) < ("function" < -5) - (yield && (yield.var += Infinity + "bar"))) {
          default:
            ;

          case c = 1 + c, ("number" << [ , 0 ][1]) - (this ^ true) >= (c = c + 1, 
            -4 >= NaN):
            ;
            break;

          case c = 1 + c, 2 + ([ , 0 ].length === 2) == -3 * 38..toString() | 38..toString() / "object" > -24..toString():
            ;
            break;

          case c = 1 + c, ("b" * "object" >> (a && (a[c = 1 + c, ([], [ , 0 ][1]) / + -0 | (yield && (yield.async %= "" & 0) || "number" ^ 3)] = /[a2][^e]+$/ % "a"))) + ([ , 0 ][1] !== -3 ^ (0 || -1)):
            ;
        }
    }), b_2.null)(a++ + (typeof f4 == "function" && --_calls_ >= 0 && f4()), false, 0)));
    function f3(a_2) {}
    var let_2 = f3();
    function f4(a_1) {
        {
            var brake24 = 5;
            L20690: do {
                try {
                    try {
                        switch (c = 1 + c, (-0 != -1) - (NaN >>> "") <= ([ , 0 ][1] !== -0, 
                        NaN > null)) {
                          default:
                            ;

                          case c = 1 + c, a += void ("object" / true) << (false * false << (2 <= 3)):
                            ;
                            break;

                          case c = 1 + c, (+ -4 >= (3 <= 0)) * (-0 % 5 >>> (false || 4)):
                            ;
                            break;

                          case c = 1 + c, ((0 == -1) >>> (c = c + 1, [ , 0 ][1])) * (3 ^ "b" ^ 4 !== "foo"):
                            ;
                            break;
                        }
                    } catch (undefined_1) {
                        c = 1 + c, (1 - Infinity === (-1 ^ 3)) << !(await && (await.a += 25 % ([ , 0 ].length === 2)));
                        c = 1 + c, (/[a2][^e]+$/ | 25 | true << 24..toString()) >> (-3 & 38..toString() || 38..toString() != null);
                        c = 1 + c, let_2 && (let_2[0 === 1 ? a : b] >>>= void (24..toString() & [ , 0 ].length === 2) != ((-5 ^ "object") === ("b" !== [ , 0 ][1])));
                    }
                } finally {
                    c = 1 + c, (a_1 && (a_1[--b + (typeof f1 == "function" && --_calls_ >= 0 && f1("c", Infinity, -5))] <<= ~4 !== (2, 
                    null))) - (3 & false ^ ([ , 0 ].length === 2) < "function");
                    {
                        var brake32 = 5;
                        do {
                            c = 1 + c, (4 || 38..toString()) > "" >>> [ , 0 ][1] === (c = c + 1, 
                            this) / ("foo" >> "undefined");
                        } while ((c = 1 + c, 22 >> 5 || this == null || (bar && (bar[c = 1 + c, 
                        (-2 - 4 === "b" > -3) << (-0 === "number" & -2 > "c")] = 5 < -5)) - (-3 == 2)) && --brake32 > 0);
                    }
                }
            } while ((0, "undefined") && "undefined" == -4 && -3 * 4 > (-5 & 24..toString()) && --brake24 > 0);
        }
    }
    var b_1 = f4("b", "c");
    function f5() {
        function f6(bar) {
            function f7(b, bar, bar) {
            }
            var foo = f7((c = 1 + c, ("foo" > -1 & (-5 ^ {})) < (5 >>> "a" > (-1 ^ {}))));
            function f8(Infinity_2) {
            }
            var a = f8`${c = 1 + c, ("function" <= "c" ^ (let_2 && (let_2.Infinity = "number" >> -3))) * ("foo" << 3 ^ ("a" | 38..toString()))}\``;
            function f9(bar_2, bar) {
            }
            var foo_2 = f9((c = 1 + c, ((bar && (bar[c = 1 + c, (c = c + 1, NaN) >>> (4 == 3) >= /[a2][^e]+$/ << -1 >> (2 != -5)] = "object" % 4)) & "foo" === false) > ((bar && (bar[c = 1 + c, 
            2 >= [ , 0 ][1] == -3 % "c" ^ 24..toString() != -3 != ("number", false)] = 25 ^ undefined)) & +[ , 0 ][1])), ..."" + b_1, 22);
        }
        var foo_2 = f6(2);
        function f10(arguments, a_1) {
            c = 1 + c, (22 ^ true && (-3 || false)) == ((arguments = -5 >= {}) ^ false * "a");
        }
        var foo_1 = f10(24..toString(), /[a2][^e]+$/, -1);
    }
    var c_2 = f5();
}

var yield_1 = f0(yield_1 += (a++ + [ yield_1, +(c = c + 1, 3 >> 23..toString() == ([] == "number")) ][--b + !("number" > "object" > (5 == 0) >= ("b" || 3) / (c = c + 1, 
-5))] || 1).toString()[b--]);

console.log(null, a, b, c, Infinity, NaN, undefined);

// (beautified)
var _calls_ = 10, a = 100, b = 10, c = 0;

function f0(b_2, bar) {
    var a = void --b;
    var await = function(bar, undefined_1) {
        var brake6 = 5;
        if (a++ + bar && 0 < brake6) {
            return c = 1 + c, c += 1, !0;
        }
        switch (a++ + delete b) {
          case --b + a++:
            --b + a && (c += 1);
            break;

          default:
            for (var brake11 = 5; (c += 1) + 3 && 0 < brake11; --brake11) {
                c = 1 + c;
            }

          case a++ + (b = a):
            switch (undefined_1 && "function" == typeof undefined_1.next && 0 <= --_calls_ && undefined_1.next((c = 1 + c, 
            ("b" !== (2 === [ , 0 ].length)) + !1), "")) {
              case b++:
                c = 1 + c, bar && (bar[c = 1 + c, !0] += (2 === [ , 0 ].length) > 38..toString()), 
                c = 1 + c, bar && (bar.done += (24..toString(), 3));
                break;

              case a++ + [ (c = 1 + c, ({} ^ 2 === [ , 0 ].length || !1) << (23..toString() >> this)) ].null:
                c = 1 + c, 23..toString();
                break;

              case c = 1 + c, ((bar && (bar.next |= 1)) >= (NaN <= {}) || a || 3).toString():
                c = 1 + c, bar && (bar[(c += 1) + (c = 1 + c, typeof !0)] &= 0), 
                c = 1 + c, undefined_1 && (undefined_1.get = 0 & 2 === [ , 0 ].length != "undefined" ^ "bar" <= this == (NaN !== []));
                break;

              case /[abc4]/g.exec((c = 1 + c, (~(("c" ^ []) << NaN) || b || 5).toString())):
                c = 1 + c, bar && (bar.in |= 0);
            }
            break;

          case (c += 1) + typeof (a++ + /[abc4]/g.exec((bar || b || 5).toString())):
        }
        return (c += 1) + b-- ? typeof bar_1 : void 0;
    }(0, ((b_2 && "function" == typeof b_2.foo && 0 <= --_calls_ && b_2.foo({}) || 3).toString()[(c += 1) + -0], 
    --b + (b_2 && "function" == typeof b_2.null && 0 <= --_calls_ && (c += 1, b_2.null)(a++ + (0 <= --_calls_ && f4()), !1, 0))));
    var let_2 = void 0;
    function f4(a_1) {
        try {
            try {
                switch (!1) {
                  default:
                  case c = 1 + (c = 1 + c), a += 0:
                    break;

                  case 0, c = 1 + (c = 1 + c), 2 * (!1 >>> (c += 1, 0)):
                }
            } catch (undefined_1) {
                c = 1 + c, await && (await.a += 25 % (2 === [ , 0 ].length)), c = 1 + c, 
                24..toString(), -3 & 38..toString() || 38..toString(), c = 1 + c, 
                let_2 && (let_2[b] >>>= 0 != void 24..toString());
            }
        } finally {
            c = 1 + c, a_1 && (a_1[--b + (0 <= --_calls_ && void 0)] <<= !0);
            for (var brake32 = 5; c = 1 + c, c = 1 + (c += 1), null == this ? 0 < --brake32 : (c = 1 + c, 
            0, !1) - !1; ) {}
        }
    }
    f4("b");
    (function() {
        var bar;
        (function(Infinity_2) {})`${c = 1 + (c = 1 + c), (!(bar = 2) ^ (let_2 && (let_2.Infinity = 0))) * (0 ^ ("a" | 38..toString()))}\``, 
        c = 1 + c, bar && (bar[c = 1 + c, c += 1, !0] = NaN), bar && (bar[c = 1 + c, 
        !1 ^ -3 != 24..toString() != !1] = 25), 24..toString(), c = 1 + c;
    })();
}

var yield_1 = f0(yield_1 += (a++ + [ yield_1, (c += 1, +(3 >> 23..toString() == ("number" == []))) ][--b + !("b" / (c += 1, 
-5) <= !1)] || 1).toString()[b--]);

console.log(null, a, b, c, 1 / 0, NaN, void 0);

export {
    _calls_,
    a,
    b,
    c
};

original result:
null 101 NaN 35 Infinity NaN undefined

uglified result:
null 101 NaN 36 Infinity NaN undefined

// reduced test case (output will differ)

// (beautified)
function f0(bar) {
    0 && (bar = function yield() {})(f4);
    function f4() {
        bar[0];
    }
    f4();
}

f0();
// output: TypeError: Cannot read property '0' of undefined
// minify: 
// options: {
//   "mangle": false,
//   "module": false,
//   "output": {
//     "v8": true
//   },
//   "validate": true
// }

minify(options):
{
  "mangle": false,
  "module": false,
  "output": {
    "v8": true
  }
}

Suspicious compress options:
  evaluate
  pure_getters
  reduce_vars
  side_effects
  unused