Merge pull request kodecocodes#66 from barbaramartina/barbara/avltree-tests

More test cases for AVLTree

Author: hollance

AVL Tree/Tests/AVLTreeTests.swift

@@ -68,6 +68,53 @@ class AVLTreeTests: XCTestCase {
       self.tree?.search(400)
     }
   }
+    
+    func testMinimumOnPopulatedTree() {
+        self.tree?.autopopulateWithNodes(500)
+        let min = self.tree?.root?.minimum()
+        XCTAssertNotNil(min, "Minimum function not working")
+    }
+    
+    func testMinimumOnSingleTreeNode() {
+        let treeNode = TreeNode(key: 1, payload: "A")
+        let min = treeNode.minimum()
+        
+        XCTAssertNotNil(min, "Minimum on single node should be returned")
+        XCTAssertEqual(min?.payload,treeNode.payload)
+    }
+    
+    func testSuccessorOfRoot() {
+        self.tree?.autopopulateWithNodes(10)
+        let successor = self.tree?.root?.successor()
+        XCTAssertNotNil(successor, "Succesor of root, non-empty tree, not found")
+    }
+    
+    func testSuccessorOfMinimum() {
+        self.tree?.autopopulateWithNodes(10)
+        
+        let minimum = self.tree?.root?.minimum()
+        XCTAssertNotNil(minimum, "Minimum should exist here")
+        
+        let successor = minimum!.successor()
+        XCTAssertNotNil(successor, "Succesor of minimum, non-empty tree, not found")
+    }
+    
+    func testSuccessorSingleNode() {
+        let singleNode = TreeNode(key: 1, payload: "A")
+        let successor = singleNode.successor()
+        XCTAssertNil(successor, "Empty node should not have succesor")
+    }
+    
+    func testDeleteExistentKey() {
+        self.tree?.delete(1)
+        XCTAssertNil(self.tree?.search(1), "Key should not exist anymore")
+    }
+
+    func testDeleteNOTExistentKey() {
+        self.tree?.delete(1056)
+        XCTAssertNil(self.tree?.search(1056), "Key should not exist")
+    }
+
 }
 
 extension AVLTree where Key : SignedIntegerType {