add red-black tree

Author: amejiarosario

src/data-structures/trees/red-black-bst.js

@@ -0,0 +1,9 @@
+const BinarySearchTree = require('./binary-search-tree');
+
+class RedBlackBST extends BinarySearchTree {
+  add(node) {
+    return super.add(node);
+  }
+}
+
+module.exports = RedBlackBST;

src/data-structures/trees/red-black-bst.spec.js

@@ -0,0 +1,32 @@
+const RedBlackBST = require('./red-black-bst.js');
+
+describe('RedBlackBST', () => {
+  let redBlackBST;
+
+  beforeEach(() => {
+    redBlackBST = new RedBlackBST();
+  });
+
+  describe('#add', () => {
+    it('should add and self-balance the tree', () => {
+      expect(redBlackBST).not.toBe(undefined);
+    });
+
+    it('should add a node', () => {
+      redBlackBST.add(1);
+      expect(redBlackBST.size).toBe(1);
+    });
+
+    it('should balance tree', () => {
+      const n1 = redBlackBST.add(1);
+      const n2 = redBlackBST.add(2);
+      const n3 = redBlackBST.add(3);
+
+      expect(n1.right.value).toBe(2);
+      expect(n2.right.value).toBe(3);
+      expect(n3.right).toBe(undefined);
+
+      expect(redBlackBST.size).toBe(3);
+    });
+  });
+});