var b = keese(null, null);

var d = keese(b, null);

assert(b < d); // forwards

var c = keese(b, d);

assert(b < c); // between

assert(c < d);

var a = keese(null, b);

assert(a < b); // backwards

function testExtremeNext() {

var biggest_single_digit;

var multi_digits = [];

var previous = null;

var n = keese();

for (var i = 0; i < 10000; i ) {

if (previous !== null) {

assertLessThan(previous, n);

testBetween(previous, n);

}

if (n.length === 1) {

biggest_single_digit = n;

} else if (multi_digits.length < 2) {

multi_digits.push(n);

}

previous = n;

n = keese(n, null);

}

if (multi_digits[1]) {

testBetween(biggest_single_digit, multi_digits[1]);

}

function testBetween(a, c) {

var b = keese(a, c);

assertLessThan(a, b);

assertLessThan(b, c);

}

return n;

}

var big_number = testExtremeNext();

function testExtremeBetween(lower, upper, forward_func) {

for (var i = 0; i < 1000; i ) {

var middle = keese(lower, upper);

assertLessThan(lower, middle);

assertLessThan(middle, upper);

if (forward_func(i)) {

lower = middle;

} else {

upper = middle;

}

}

}

(function() {

var one = keese();

var two = keese(one, null);

var forward_funcs = [

function() { return true; },

function() { return false; },

// arbitrarilly descend forwards or backwards pseudo randomly or whatever

function(i) { return i % 3 === 0 || i % 7 > 3; },

];

var boundses = [

[one, two],

[one, big_number],

];

for (var i = 0; i < boundses.length; i ) {

for (var j = 0; j < forward_funcs.length; j ) {

testExtremeBetween(boundses[i][0], boundses[i][1], forward_funcs[j]);

}

}

})();

assert.throws(function() { keese(keese(), keese()); });

function assertLessThan(a, b) {

assert(a < b, JSON.stringify(a) " < " JSON.stringify(b));

}

var some_value = keese();

runTests(null, null);

runTests(some_value, null);

runTests(null, some_value);

runTests(some_value, keese(some_value));

function runTests(low, high) {

testSize(0);

testSize(1);

testSize(2);

testSize(3);

testSize(1000);

function testSize(size) {

var array = keese(low, high, size);

assert(array.length === size, "array size expected to be: " size);

var previous = low;

array.forEach(function(item) {

if (previous != null) assert(previous < item, JSON.stringify(previous) " < " JSON.stringify(item));

previous = item;

});

if (previous != null && high != null) assert(previous < high, JSON.stringify(previous) " < " JSON.stringify(high));

}

}