File: /var/dev/nowruzgan/rest/node_modules/binary-search-tree/test/avltree.test.js
var should = require('chai').should()
, assert = require('chai').assert
, AVLTree = require('../index').AVLTree
, _ = require('underscore')
, customUtils = require('../lib/customUtils')
;
describe('AVL tree', function () {
describe('Sanity checks', function () {
it('Checking that all nodes heights are correct', function () {
var _AVLTree = AVLTree._AVLTree
, avlt = new _AVLTree({ key: 10 })
, l = new _AVLTree({ key: 5 })
, r = new _AVLTree({ key: 15 })
, ll = new _AVLTree({ key: 3 })
, lr = new _AVLTree({ key: 8 })
, rl = new _AVLTree({ key: 13 })
, rr = new _AVLTree({ key: 18 })
, lrl = new _AVLTree({ key: 7 })
, lrll = new _AVLTree({ key: 6 })
;
// With a balanced tree
avlt.left = l;
avlt.right = r;
l.left = ll;
l.right = lr;
r.left = rl;
r.right = rr;
(function () { avlt.checkHeightCorrect() }).should.throw();
avlt.height = 1;
(function () { avlt.checkHeightCorrect() }).should.throw();
l.height = 1;
(function () { avlt.checkHeightCorrect() }).should.throw();
r.height = 1;
(function () { avlt.checkHeightCorrect() }).should.throw();
ll.height = 1;
(function () { avlt.checkHeightCorrect() }).should.throw();
lr.height = 1;
(function () { avlt.checkHeightCorrect() }).should.throw();
rl.height = 1;
(function () { avlt.checkHeightCorrect() }).should.throw();
rr.height = 1;
(function () { avlt.checkHeightCorrect() }).should.throw();
avlt.height = 2;
(function () { avlt.checkHeightCorrect() }).should.throw();
l.height = 2;
(function () { avlt.checkHeightCorrect() }).should.throw();
r.height = 2;
(function () { avlt.checkHeightCorrect() }).should.throw();
avlt.height = 3;
avlt.checkHeightCorrect(); // Correct
// With an unbalanced tree
lr.left = lrl;
(function () { avlt.checkHeightCorrect() }).should.throw();
lrl.left = lrll;
(function () { avlt.checkHeightCorrect() }).should.throw();
lrl.height = 1;
(function () { avlt.checkHeightCorrect() }).should.throw();
lrll.height = 1;
(function () { avlt.checkHeightCorrect() }).should.throw();
lrl.height = 2;
(function () { avlt.checkHeightCorrect() }).should.throw();
lr.height = 3;
(function () { avlt.checkHeightCorrect() }).should.throw();
l.height = 4;
(function () { avlt.checkHeightCorrect() }).should.throw();
avlt.height = 5;
avlt.checkHeightCorrect(); // Correct
});
it('Calculate the balance factor', function () {
var _AVLTree = AVLTree._AVLTree
, avlt = new _AVLTree({ key: 10 })
, l = new _AVLTree({ key: 5 })
, r = new _AVLTree({ key: 15 })
, ll = new _AVLTree({ key: 3 })
, lr = new _AVLTree({ key: 8 })
, rl = new _AVLTree({ key: 13 })
, rr = new _AVLTree({ key: 18 })
, lrl = new _AVLTree({ key: 7 })
, lrll = new _AVLTree({ key: 6 })
;
// With a balanced tree
avlt.left = l;
avlt.right = r;
l.left = ll;
l.right = lr;
r.left = rl;
r.right = rr;
ll.height = 1;
rl.height = 1;
rr.height = 1;
avlt.height = 2;
r.height = 2;
lr.left = lrl;
lrl.left = lrll;
lrl.height = 1;
lrll.height = 1;
lrl.height = 2;
lr.height = 3;
l.height = 4;
avlt.height = 5;
avlt.checkHeightCorrect(); // Correct
lrll.balanceFactor().should.equal(0);
lrl.balanceFactor().should.equal(1);
ll.balanceFactor().should.equal(0);
lr.balanceFactor().should.equal(2);
rl.balanceFactor().should.equal(0);
rr.balanceFactor().should.equal(0);
l.balanceFactor().should.equal(-2);
r.balanceFactor().should.equal(0);
avlt.balanceFactor().should.equal(2);
});
it('Can check that a tree is balanced', function () {
var _AVLTree = AVLTree._AVLTree
, avlt = new _AVLTree({ key: 10 })
, l = new _AVLTree({ key: 5 })
, r = new _AVLTree({ key: 15 })
, ll = new _AVLTree({ key: 3 })
, lr = new _AVLTree({ key: 8 })
, rl = new _AVLTree({ key: 13 })
, rr = new _AVLTree({ key: 18 })
avlt.left = l;
avlt.right = r;
l.left = ll;
l.right = lr;
r.left = rl;
r.right = rr;
ll.height = 1;
lr.height = 1;
rl.height = 1;
rr.height = 1;
l.height = 2;
r.height = 2;
avlt.height = 3;
avlt.checkBalanceFactors();
r.height = 0;
(function () { avlt.checkBalanceFactors(); }).should.throw();
r.height = 4;
(function () { avlt.checkBalanceFactors(); }).should.throw();
r.height = 2;
avlt.checkBalanceFactors();
ll.height = -1;
(function () { avlt.checkBalanceFactors(); }).should.throw();
ll.height = 3;
(function () { avlt.checkBalanceFactors(); }).should.throw();
ll.height = 1;
avlt.checkBalanceFactors();
rl.height = -1;
(function () { avlt.checkBalanceFactors(); }).should.throw();
rl.height = 3;
(function () { avlt.checkBalanceFactors(); }).should.throw();
rl.height = 1;
avlt.checkBalanceFactors();
});
}); // ==== End of 'Sanity checks' ==== //
describe('Insertion', function () {
it('The root has a height of 1', function () {
var avlt = new AVLTree();
avlt.insert(10, 'root');
avlt.tree.height.should.equal(1);
});
it('Insert at the root if its the first insertion', function () {
var avlt = new AVLTree();
avlt.insert(10, 'some data');
avlt.checkIsAVLT();
avlt.tree.key.should.equal(10);
_.isEqual(avlt.tree.data, ['some data']).should.equal(true);
assert.isNull(avlt.tree.left);
assert.isNull(avlt.tree.right);
});
it('If uniqueness constraint not enforced, we can insert different data for same key', function () {
var avlt = new AVLTree();
avlt.insert(10, 'some data');
avlt.insert(3, 'hello');
avlt.insert(3, 'world');
avlt.checkIsAVLT();
_.isEqual(avlt.search(3), ['hello', 'world']).should.equal(true);
avlt.insert(12, 'a');
avlt.insert(12, 'b');
avlt.checkIsAVLT();
_.isEqual(avlt.search(12), ['a', 'b']).should.equal(true);
});
it('If uniqueness constraint is enforced, we cannot insert different data for same key', function () {
var avlt = new AVLTree({ unique: true });
avlt.insert(10, 'some data');
avlt.insert(3, 'hello');
try {
avlt.insert(3, 'world');
} catch (e) {
e.errorType.should.equal('uniqueViolated');
e.key.should.equal(3);
}
avlt.checkIsAVLT();
_.isEqual(avlt.search(3), ['hello']).should.equal(true);
avlt.insert(12, 'a');
try {
avlt.insert(12, 'world');
} catch (e) {
e.errorType.should.equal('uniqueViolated');
e.key.should.equal(12);
}
avlt.checkIsAVLT();
_.isEqual(avlt.search(12), ['a']).should.equal(true);
});
it('Can insert 0 or the empty string', function () {
var avlt = new AVLTree();
avlt.insert(0, 'some data');
avlt.checkIsAVLT();
avlt.tree.key.should.equal(0);
_.isEqual(avlt.tree.data, ['some data']).should.equal(true);
avlt = new AVLTree();
avlt.insert('', 'some other data');
avlt.checkIsAVLT();
avlt.tree.key.should.equal('');
_.isEqual(avlt.tree.data, ['some other data']).should.equal(true);
});
it('Auto-balancing insertions', function () {
var avlt = new AVLTree()
, avlt2 = new AVLTree()
, avlt3 = new AVLTree()
;
// Balancing insertions on the left
avlt.tree.getNumberOfKeys().should.equal(0);
avlt.insert(18);
avlt.tree.getNumberOfKeys().should.equal(1);
avlt.tree.checkIsAVLT();
avlt.insert(15);
avlt.tree.getNumberOfKeys().should.equal(2);
avlt.tree.checkIsAVLT();
avlt.insert(13);
avlt.tree.getNumberOfKeys().should.equal(3);
avlt.tree.checkIsAVLT();
avlt.insert(10);
avlt.tree.getNumberOfKeys().should.equal(4);
avlt.tree.checkIsAVLT();
avlt.insert(8);
avlt.tree.getNumberOfKeys().should.equal(5);
avlt.tree.checkIsAVLT();
avlt.insert(5);
avlt.tree.getNumberOfKeys().should.equal(6);
avlt.tree.checkIsAVLT();
avlt.insert(3);
avlt.tree.getNumberOfKeys().should.equal(7);
avlt.tree.checkIsAVLT();
// Balancing insertions on the right
avlt2.tree.getNumberOfKeys().should.equal(0);
avlt2.insert(3);
avlt2.tree.getNumberOfKeys().should.equal(1);
avlt2.tree.checkIsAVLT();
avlt2.insert(5);
avlt2.tree.getNumberOfKeys().should.equal(2);
avlt2.tree.checkIsAVLT();
avlt2.insert(8);
avlt2.tree.getNumberOfKeys().should.equal(3);
avlt2.tree.checkIsAVLT();
avlt2.insert(10);
avlt2.tree.getNumberOfKeys().should.equal(4);
avlt2.tree.checkIsAVLT();
avlt2.insert(13);
avlt2.tree.getNumberOfKeys().should.equal(5);
avlt2.tree.checkIsAVLT();
avlt2.insert(15);
avlt2.tree.getNumberOfKeys().should.equal(6);
avlt2.tree.checkIsAVLT();
avlt2.insert(18);
avlt2.tree.getNumberOfKeys().should.equal(7);
avlt2.tree.checkIsAVLT();
// Balancing already-balanced insertions
avlt3.tree.getNumberOfKeys().should.equal(0);
avlt3.insert(10);
avlt3.tree.getNumberOfKeys().should.equal(1);
avlt3.tree.checkIsAVLT();
avlt3.insert(5);
avlt3.tree.getNumberOfKeys().should.equal(2);
avlt3.tree.checkIsAVLT();
avlt3.insert(15);
avlt3.tree.getNumberOfKeys().should.equal(3);
avlt3.tree.checkIsAVLT();
avlt3.insert(3);
avlt3.tree.getNumberOfKeys().should.equal(4);
avlt3.tree.checkIsAVLT();
avlt3.insert(8);
avlt3.tree.getNumberOfKeys().should.equal(5);
avlt3.tree.checkIsAVLT();
avlt3.insert(13);
avlt3.tree.getNumberOfKeys().should.equal(6);
avlt3.tree.checkIsAVLT();
avlt3.insert(18);
avlt3.tree.getNumberOfKeys().should.equal(7);
avlt3.tree.checkIsAVLT();
});
it('Can insert a lot of keys and still get an AVLT (sanity check)', function () {
var avlt = new AVLTree({ unique: true });
customUtils.getRandomArray(1000).forEach(function (n) {
avlt.insert(n, 'some data');
avlt.checkIsAVLT();
});
});
}); // ==== End of 'Insertion' ==== //
describe('Search', function () {
it('Can find data in an AVLT', function () {
var avlt = new AVLTree()
, i;
customUtils.getRandomArray(100).forEach(function (n) {
avlt.insert(n, 'some data for ' + n);
});
avlt.checkIsAVLT();
for (i = 0; i < 100; i += 1) {
_.isEqual(avlt.search(i), ['some data for ' + i]).should.equal(true);
}
});
it('If no data can be found, return an empty array', function () {
var avlt = new AVLTree();
customUtils.getRandomArray(100).forEach(function (n) {
if (n !== 63) {
avlt.insert(n, 'some data for ' + n);
}
});
avlt.checkIsAVLT();
avlt.search(-2).length.should.equal(0);
avlt.search(100).length.should.equal(0);
avlt.search(101).length.should.equal(0);
avlt.search(63).length.should.equal(0);
});
it('Can search for data between two bounds', function () {
var avlt = new AVLTree();
[10, 5, 15, 3, 8, 13, 18].forEach(function (k) {
avlt.insert(k, 'data ' + k);
});
assert.deepEqual(avlt.betweenBounds({ $gte: 8, $lte: 15 }), ['data 8', 'data 10', 'data 13', 'data 15']);
assert.deepEqual(avlt.betweenBounds({ $gt: 8, $lt: 15 }), ['data 10', 'data 13']);
});
it('Bounded search can handle cases where query contains both $lt and $lte, or both $gt and $gte', function () {
var avlt = new AVLTree();
[10, 5, 15, 3, 8, 13, 18].forEach(function (k) {
avlt.insert(k, 'data ' + k);
});
assert.deepEqual(avlt.betweenBounds({ $gt:8, $gte: 8, $lte: 15 }), ['data 10', 'data 13', 'data 15']);
assert.deepEqual(avlt.betweenBounds({ $gt:5, $gte: 8, $lte: 15 }), ['data 8', 'data 10', 'data 13', 'data 15']);
assert.deepEqual(avlt.betweenBounds({ $gt:8, $gte: 5, $lte: 15 }), ['data 10', 'data 13', 'data 15']);
assert.deepEqual(avlt.betweenBounds({ $gte: 8, $lte: 15, $lt: 15 }), ['data 8', 'data 10', 'data 13']);
assert.deepEqual(avlt.betweenBounds({ $gte: 8, $lte: 18, $lt: 15 }), ['data 8', 'data 10', 'data 13']);
assert.deepEqual(avlt.betweenBounds({ $gte: 8, $lte: 15, $lt: 18 }), ['data 8', 'data 10', 'data 13', 'data 15']);
});
it('Bounded search can work when one or both boundaries are missing', function () {
var avlt = new AVLTree();
[10, 5, 15, 3, 8, 13, 18].forEach(function (k) {
avlt.insert(k, 'data ' + k);
});
assert.deepEqual(avlt.betweenBounds({ $gte: 11 }), ['data 13', 'data 15', 'data 18']);
assert.deepEqual(avlt.betweenBounds({ $lte: 9 }), ['data 3', 'data 5', 'data 8']);
});
}); /// ==== End of 'Search' ==== //
describe('Deletion', function () {
it('Deletion does nothing on an empty tree', function () {
var avlt = new AVLTree()
, avltu = new AVLTree({ unique: true });
avlt.getNumberOfKeys().should.equal(0);
avltu.getNumberOfKeys().should.equal(0);
avlt.delete(5);
avltu.delete(5);
avlt.tree.hasOwnProperty('key').should.equal(false);
avltu.tree.hasOwnProperty('key').should.equal(false);
avlt.tree.data.length.should.equal(0);
avltu.tree.data.length.should.equal(0);
avlt.getNumberOfKeys().should.equal(0);
avltu.getNumberOfKeys().should.equal(0);
});
it('Deleting a non-existent key doesnt have any effect', function () {
var avlt = new AVLTree();
[10, 5, 3, 8, 15, 12, 37].forEach(function (k) {
avlt.insert(k, 'some ' + k);
});
function checkavlt () {
[10, 5, 3, 8, 15, 12, 37].forEach(function (k) {
_.isEqual(avlt.search(k), ['some ' + k]).should.equal(true);
});
}
checkavlt();
avlt.getNumberOfKeys().should.equal(7);
avlt.delete(2);
checkavlt(); avlt.checkIsAVLT(); avlt.getNumberOfKeys().should.equal(7);
avlt.delete(4);
checkavlt(); avlt.checkIsAVLT(); avlt.getNumberOfKeys().should.equal(7);
avlt.delete(9);
checkavlt(); avlt.checkIsAVLT(); avlt.getNumberOfKeys().should.equal(7);
avlt.delete(6);
checkavlt(); avlt.checkIsAVLT(); avlt.getNumberOfKeys().should.equal(7);
avlt.delete(11);
checkavlt(); avlt.checkIsAVLT(); avlt.getNumberOfKeys().should.equal(7);
avlt.delete(14);
checkavlt(); avlt.checkIsAVLT(); avlt.getNumberOfKeys().should.equal(7);
avlt.delete(20);
checkavlt(); avlt.checkIsAVLT(); avlt.getNumberOfKeys().should.equal(7);
avlt.delete(200);
checkavlt(); avlt.checkIsAVLT(); avlt.getNumberOfKeys().should.equal(7);
});
it('Able to delete the root if it is also a leaf', function () {
var avlt = new AVLTree();
avlt.insert(10, 'hello');
avlt.tree.key.should.equal(10);
_.isEqual(avlt.tree.data, ['hello']).should.equal(true);
avlt.getNumberOfKeys().should.equal(1);
avlt.delete(10);
avlt.tree.hasOwnProperty('key').should.equal(false);
avlt.tree.data.length.should.equal(0);
avlt.getNumberOfKeys().should.equal(0);
});
it('Able to delete leaf nodes that are non-root', function () {
var avlt;
// This will create an AVL tree with leaves 3, 8, 12, 37
// (do a pretty print to see this)
function recreateavlt () {
avlt = new AVLTree();
[10, 5, 3, 8, 15, 12, 37].forEach(function (k) {
avlt.insert(k, 'some ' + k);
});
avlt.getNumberOfKeys().should.equal(7);
}
// Check that only keys in array theRemoved were removed
function checkRemoved (theRemoved) {
[10, 5, 3, 8, 15, 12, 37].forEach(function (k) {
if (theRemoved.indexOf(k) !== -1) {
avlt.search(k).length.should.equal(0);
} else {
_.isEqual(avlt.search(k), ['some ' + k]).should.equal(true);
}
});
avlt.getNumberOfKeys().should.equal(7 - theRemoved.length);
}
recreateavlt();
avlt.delete(3);
avlt.checkIsAVLT();
checkRemoved([3]);
recreateavlt();
avlt.delete(8);
avlt.checkIsAVLT();
checkRemoved([8]);
recreateavlt();
avlt.delete(12);
avlt.checkIsAVLT();
checkRemoved([12]);
// Delete all leaves in a way that makes the tree unbalanced
recreateavlt();
avlt.delete(37);
avlt.checkIsAVLT();
checkRemoved([37]);
avlt.delete(12);
avlt.checkIsAVLT();
checkRemoved([12, 37]);
avlt.delete(15);
avlt.checkIsAVLT();
checkRemoved([12, 15, 37]);
avlt.delete(3);
avlt.checkIsAVLT();
checkRemoved([3, 12, 15, 37]);
avlt.delete(5);
avlt.checkIsAVLT();
checkRemoved([3, 5, 12, 15, 37]);
avlt.delete(10);
avlt.checkIsAVLT();
checkRemoved([3, 5, 10, 12, 15, 37]);
avlt.delete(8);
avlt.checkIsAVLT();
checkRemoved([3, 5, 8, 10, 12, 15, 37]);
});
it('Able to delete the root if it has only one child', function () {
var avlt;
// Root has only one child, on the left
avlt = new AVLTree();
[10, 5].forEach(function (k) {
avlt.insert(k, 'some ' + k);
});
avlt.getNumberOfKeys().should.equal(2);
avlt.delete(10);
avlt.checkIsAVLT();
avlt.getNumberOfKeys().should.equal(1);
_.isEqual(avlt.search(5), ['some 5']).should.equal(true);
avlt.search(10).length.should.equal(0);
// Root has only one child, on the right
avlt = new AVLTree();
[10, 15].forEach(function (k) {
avlt.insert(k, 'some ' + k);
});
avlt.getNumberOfKeys().should.equal(2);
avlt.delete(10);
avlt.checkIsAVLT();
avlt.getNumberOfKeys().should.equal(1);
_.isEqual(avlt.search(15), ['some 15']).should.equal(true);
avlt.search(10).length.should.equal(0);
});
it('Able to delete non root nodes that have only one child', function () {
var avlt = new AVLTree()
, firstSet = [10, 5, 15, 3, 1, 4, 20]
, secondSet = [10, 5, 15, 3, 1, 4, 20, 17, 25]
;
// Check that only keys in array theRemoved were removed
function checkRemoved (set, theRemoved) {
set.forEach(function (k) {
if (theRemoved.indexOf(k) !== -1) {
avlt.search(k).length.should.equal(0);
} else {
_.isEqual(avlt.search(k), ['some ' + k]).should.equal(true);
}
});
avlt.getNumberOfKeys().should.equal(set.length - theRemoved.length);
}
// First set: no rebalancing necessary
firstSet.forEach(function (k) {
avlt.insert(k, 'some ' + k);
});
avlt.getNumberOfKeys().should.equal(7);
avlt.checkIsAVLT();
avlt.delete(4); // Leaf
avlt.checkIsAVLT();
checkRemoved(firstSet, [4]);
avlt.delete(3); // Node with only one child (on the left)
avlt.checkIsAVLT();
checkRemoved(firstSet, [3, 4]);
avlt.delete(10); // Leaf
avlt.checkIsAVLT();
checkRemoved(firstSet, [3, 4, 10]);
avlt.delete(15); // Node with only one child (on the right)
avlt.checkIsAVLT();
checkRemoved(firstSet, [3, 4, 10, 15]);
// Second set: some rebalancing necessary
avlt = new AVLTree();
secondSet.forEach(function (k) {
avlt.insert(k, 'some ' + k);
});
avlt.delete(4); // Leaf
avlt.checkIsAVLT();
checkRemoved(secondSet, [4]);
avlt.delete(3); // Node with only one child (on the left), causes rebalancing
avlt.checkIsAVLT();
checkRemoved(secondSet, [3, 4]);
});
it('Can delete the root if it has 2 children', function () {
var avlt = new AVLTree();
// No rebalancing needed
[10, 5, 15, 3, 8, 12, 37].forEach(function (k) {
avlt.insert(k, 'some ' + k);
});
avlt.getNumberOfKeys().should.equal(7);
avlt.delete(10);
avlt.checkIsAVLT();
avlt.getNumberOfKeys().should.equal(6);
[5, 3, 8, 15, 12, 37].forEach(function (k) {
_.isEqual(avlt.search(k), ['some ' + k]).should.equal(true);
});
avlt.search(10).length.should.equal(0);
// Rebalancing needed
avlt = new AVLTree();
[10, 5, 15, 8, 12, 37, 42].forEach(function (k) {
avlt.insert(k, 'some ' + k);
});
avlt.getNumberOfKeys().should.equal(7);
avlt.delete(10);
avlt.checkIsAVLT();
avlt.getNumberOfKeys().should.equal(6);
[5, 8, 15, 12, 37, 42].forEach(function (k) {
_.isEqual(avlt.search(k), ['some ' + k]).should.equal(true);
});
avlt.search(10).length.should.equal(0);
});
it('Can delete a non-root node that has two children', function () {
var avlt;
// On the left
avlt = new AVLTree();
[10, 5, 15, 3, 8, 12, 20, 1, 4, 6, 9, 11, 13, 19, 42, 3.5].forEach(function (k) {
avlt.insert(k, 'some ' + k);
});
avlt.getNumberOfKeys().should.equal(16);
avlt.delete(5);
avlt.checkIsAVLT();
avlt.getNumberOfKeys().should.equal(15);
[10, 3, 1, 4, 8, 6, 9, 15, 12, 11, 13, 20, 19, 42, 3.5].forEach(function (k) {
_.isEqual(avlt.search(k), ['some ' + k]).should.equal(true);
});
avlt.search(5).length.should.equal(0);
// On the right
avlt = new AVLTree();
[10, 5, 15, 3, 8, 12, 20, 1, 4, 6, 9, 11, 13, 19, 42, 12.5].forEach(function (k) {
avlt.insert(k, 'some ' + k);
});
avlt.getNumberOfKeys().should.equal(16);
avlt.delete(15);
avlt.checkIsAVLT();
avlt.getNumberOfKeys().should.equal(15);
[10, 3, 1, 4, 8, 6, 9, 5, 12, 11, 13, 20, 19, 42, 12.5].forEach(function (k) {
_.isEqual(avlt.search(k), ['some ' + k]).should.equal(true);
});
avlt.search(15).length.should.equal(0);
});
it('If no value is provided, it will delete the entire node even if there are multiple pieces of data', function () {
var avlt = new AVLTree();
avlt.insert(10, 'yes');
avlt.insert(5, 'hello');
avlt.insert(3, 'yes');
avlt.insert(5, 'world');
avlt.insert(8, 'yes');
assert.deepEqual(avlt.search(5), ['hello', 'world']);
avlt.getNumberOfKeys().should.equal(4);
avlt.delete(5);
avlt.checkIsAVLT();
avlt.search(5).length.should.equal(0);
avlt.getNumberOfKeys().should.equal(3);
});
it('Can remove only one value from an array', function () {
var avlt = new AVLTree();
avlt.insert(10, 'yes');
avlt.insert(5, 'hello');
avlt.insert(3, 'yes');
avlt.insert(5, 'world');
avlt.insert(8, 'yes');
assert.deepEqual(avlt.search(5), ['hello', 'world']);
avlt.getNumberOfKeys().should.equal(4);
avlt.delete(5, 'hello');
avlt.checkIsAVLT();
assert.deepEqual(avlt.search(5), ['world']);
avlt.getNumberOfKeys().should.equal(4);
});
it('Removes nothing if value doesnt match', function () {
var avlt = new AVLTree();
avlt.insert(10, 'yes');
avlt.insert(5, 'hello');
avlt.insert(3, 'yes');
avlt.insert(5, 'world');
avlt.insert(8, 'yes');
assert.deepEqual(avlt.search(5), ['hello', 'world']);
avlt.getNumberOfKeys().should.equal(4);
avlt.delete(5, 'nope');
avlt.checkIsAVLT();
assert.deepEqual(avlt.search(5), ['hello', 'world']);
avlt.getNumberOfKeys().should.equal(4);
});
it('If value provided but node contains only one value, remove entire node', function () {
var avlt = new AVLTree();
avlt.insert(10, 'yes');
avlt.insert(5, 'hello');
avlt.insert(3, 'yes2');
avlt.insert(5, 'world');
avlt.insert(8, 'yes3');
assert.deepEqual(avlt.search(3), ['yes2']);
avlt.getNumberOfKeys().should.equal(4);
avlt.delete(3, 'yes2');
avlt.checkIsAVLT();
avlt.search(3).length.should.equal(0);
avlt.getNumberOfKeys().should.equal(3);
});
it('Can remove the root from a tree with height 2 when the root has two children (special case)', function () {
var avlt = new AVLTree();
avlt.insert(10, 'maybe');
avlt.insert(5, 'no');
avlt.insert(15, 'yes');
avlt.getNumberOfKeys().should.equal(3);
avlt.delete(10);
avlt.checkIsAVLT();
avlt.getNumberOfKeys().should.equal(2);
assert.deepEqual(avlt.search(5), ['no']);
assert.deepEqual(avlt.search(15), ['yes']);
});
it('Can remove the root from a tree with height 3 when the root has two children (special case where the two children themselves have children)', function () {
var avlt = new AVLTree();
avlt.insert(10, 'maybe');
avlt.insert(5, 'no');
avlt.insert(15, 'yes');
avlt.insert(2, 'no');
avlt.insert(35, 'yes');
avlt.getNumberOfKeys().should.equal(5);
avlt.delete(10);
avlt.checkIsAVLT();
avlt.getNumberOfKeys().should.equal(4);
assert.deepEqual(avlt.search(5), ['no']);
assert.deepEqual(avlt.search(15), ['yes']);
});
}); // ==== End of 'Deletion' ==== //
it('Can use undefined as key and value', function () {
function compareKeys (a, b) {
if (a === undefined && b === undefined) { return 0; }
if (a === undefined) { return -1; }
if (b === undefined) { return 1; }
if (a < b) { return -1; }
if (a > b) { return 1; }
if (a === b) { return 0; }
}
var avlt = new AVLTree({ compareKeys: compareKeys });
avlt.insert(2, undefined);
avlt.checkIsAVLT();
avlt.getNumberOfKeys().should.equal(1);
assert.deepEqual(avlt.search(2), [undefined]);
assert.deepEqual(avlt.search(undefined), []);
avlt.insert(undefined, 'hello');
avlt.checkIsAVLT();
avlt.getNumberOfKeys().should.equal(2);
assert.deepEqual(avlt.search(2), [undefined]);
assert.deepEqual(avlt.search(undefined), ['hello']);
avlt.insert(undefined, 'world');
avlt.checkIsAVLT();
avlt.getNumberOfKeys().should.equal(2);
assert.deepEqual(avlt.search(2), [undefined]);
assert.deepEqual(avlt.search(undefined), ['hello', 'world']);
avlt.insert(4, undefined);
avlt.checkIsAVLT();
avlt.getNumberOfKeys().should.equal(3);
assert.deepEqual(avlt.search(2), [undefined]);
assert.deepEqual(avlt.search(4), [undefined]);
assert.deepEqual(avlt.search(undefined), ['hello', 'world']);
avlt.delete(undefined, 'hello');
avlt.checkIsAVLT();
avlt.getNumberOfKeys().should.equal(3);
assert.deepEqual(avlt.search(2), [undefined]);
assert.deepEqual(avlt.search(4), [undefined]);
assert.deepEqual(avlt.search(undefined), ['world']);
avlt.delete(undefined);
avlt.checkIsAVLT();
avlt.getNumberOfKeys().should.equal(2);
assert.deepEqual(avlt.search(2), [undefined]);
assert.deepEqual(avlt.search(4), [undefined]);
assert.deepEqual(avlt.search(undefined), []);
avlt.delete(2, undefined);
avlt.checkIsAVLT();
avlt.getNumberOfKeys().should.equal(1);
assert.deepEqual(avlt.search(2), []);
assert.deepEqual(avlt.search(4), [undefined]);
assert.deepEqual(avlt.search(undefined), []);
avlt.delete(4);
avlt.checkIsAVLT();
avlt.getNumberOfKeys().should.equal(0);
assert.deepEqual(avlt.search(2), []);
assert.deepEqual(avlt.search(4), []);
assert.deepEqual(avlt.search(undefined), []);
});
it('Can use null as key and value', function () {
function compareKeys (a, b) {
if (a === null && b === null) { return 0; }
if (a === null) { return -1; }
if (b === null) { return 1; }
if (a < b) { return -1; }
if (a > b) { return 1; }
if (a === b) { return 0; }
}
var avlt = new AVLTree({ compareKeys: compareKeys });
avlt.insert(2, null);
avlt.checkIsAVLT();
avlt.getNumberOfKeys().should.equal(1);
assert.deepEqual(avlt.search(2), [null]);
assert.deepEqual(avlt.search(null), []);
avlt.insert(null, 'hello');
avlt.checkIsAVLT();
avlt.getNumberOfKeys().should.equal(2);
assert.deepEqual(avlt.search(2), [null]);
assert.deepEqual(avlt.search(null), ['hello']);
avlt.insert(null, 'world');
avlt.checkIsAVLT();
avlt.getNumberOfKeys().should.equal(2);
assert.deepEqual(avlt.search(2), [null]);
assert.deepEqual(avlt.search(null), ['hello', 'world']);
avlt.insert(4, null);
avlt.checkIsAVLT();
avlt.getNumberOfKeys().should.equal(3);
assert.deepEqual(avlt.search(2), [null]);
assert.deepEqual(avlt.search(4), [null]);
assert.deepEqual(avlt.search(null), ['hello', 'world']);
avlt.delete(null, 'hello');
avlt.checkIsAVLT();
avlt.getNumberOfKeys().should.equal(3);
assert.deepEqual(avlt.search(2), [null]);
assert.deepEqual(avlt.search(4), [null]);
assert.deepEqual(avlt.search(null), ['world']);
avlt.delete(null);
avlt.checkIsAVLT();
avlt.getNumberOfKeys().should.equal(2);
assert.deepEqual(avlt.search(2), [null]);
assert.deepEqual(avlt.search(4), [null]);
assert.deepEqual(avlt.search(null), []);
avlt.delete(2, null);
avlt.checkIsAVLT();
avlt.getNumberOfKeys().should.equal(1);
assert.deepEqual(avlt.search(2), []);
assert.deepEqual(avlt.search(4), [null]);
assert.deepEqual(avlt.search(null), []);
avlt.delete(4);
avlt.checkIsAVLT();
avlt.getNumberOfKeys().should.equal(0);
assert.deepEqual(avlt.search(2), []);
assert.deepEqual(avlt.search(4), []);
assert.deepEqual(avlt.search(null), []);
});
describe('Execute on every node (=tree traversal)', function () {
it('Can execute a function on every node', function () {
var avlt = new AVLTree()
, keys = []
, executed = 0
;
avlt.insert(10, 'yes');
avlt.insert(5, 'hello');
avlt.insert(3, 'yes2');
avlt.insert(8, 'yes3');
avlt.insert(15, 'yes3');
avlt.insert(159, 'yes3');
avlt.insert(11, 'yes3');
avlt.executeOnEveryNode(function (node) {
keys.push(node.key);
executed += 1;
});
assert.deepEqual(keys, [3, 5, 8, 10, 11, 15, 159]);
executed.should.equal(7);
});
}); // ==== End of 'Execute on every node' ==== //
// This test performs several inserts and deletes at random, always checking the content
// of the tree are as expected and the binary search tree constraint is respected
// This test is important because it can catch bugs other tests can't
// By their nature, BSTs can be hard to test (many possible cases, bug at one operation whose
// effect begins to be felt only after several operations etc.)
describe('Randomized test (takes much longer than the rest of the test suite)', function () {
var avlt = new AVLTree()
, data = {};
// Check a avlt against a simple key => [data] object
function checkDataIsTheSame (avlt, data) {
var avltDataElems = [];
// avltDataElems is a simple array containing every piece of data in the tree
avlt.executeOnEveryNode(function (node) {
var i;
for (i = 0; i < node.data.length; i += 1) {
avltDataElems.push(node.data[i]);
}
});
// Number of key and number of pieces of data match
avlt.getNumberOfKeys().should.equal(Object.keys(data).length);
_.reduce(_.map(data, function (d) { return d.length; }), function (memo, n) { return memo + n; }, 0).should.equal(avltDataElems.length);
// Compare data
Object.keys(data).forEach(function (key) {
checkDataEquality(avlt.search(key), data[key]);
});
}
// Check two pieces of data coming from the avlt and data are the same
function checkDataEquality (fromavlt, fromData) {
if (fromavlt.length === 0) {
if (fromData) { fromData.length.should.equal(0); }
}
assert.deepEqual(fromavlt, fromData);
}
// Tests the tree structure (deletions concern the whole tree, deletion of some data in a node is well tested above)
it('Inserting and deleting entire nodes', function () {
// You can skew to be more insertive or deletive, to test all cases
function launchRandomTest (nTests, proba) {
var i, key, dataPiece, possibleKeys;
for (i = 0; i < nTests; i += 1) {
if (Math.random() > proba) { // Deletion
possibleKeys = Object.keys(data);
if (possibleKeys.length > 0) {
key = possibleKeys[Math.floor(possibleKeys.length * Math.random()).toString()];
} else {
key = Math.floor(70 * Math.random()).toString();
}
delete data[key];
avlt.delete(key);
} else { // Insertion
key = Math.floor(70 * Math.random()).toString();
dataPiece = Math.random().toString().substring(0, 6);
avlt.insert(key, dataPiece);
if (data[key]) {
data[key].push(dataPiece);
} else {
data[key] = [dataPiece];
}
}
// Check the avlt constraint are still met and the data is correct
avlt.checkIsAVLT();
checkDataIsTheSame(avlt, data);
}
}
launchRandomTest(1000, 0.65);
launchRandomTest(2000, 0.35);
});
}); // ==== End of 'Randomized test' ==== //
});