Data Structure : Convert live test to Jest test. Remove live code & console.log

Data-Structures/Heap/MinPriorityQueue.js

@@ -53,8 +53,8 @@ class MinPriorityQueue {
   }
 
   // prints the heap
-  print () {
-    console.log(this.heap.slice(1))
+  print (output = value => console.log(value)) {
+    output(this.heap.slice(1))
   }
 
   // heap sorting can be done by performing
@@ -109,17 +109,4 @@ class MinPriorityQueue {
   }
 }
 
-// testing
-const q = new MinPriorityQueue(8)
-
-q.insert(5)
-q.insert(2)
-q.insert(4)
-q.insert(1)
-q.insert(7)
-q.insert(6)
-q.insert(3)
-q.insert(8)
-q.print() // [ 1, 2, 3, 5, 7, 6, 4, 8 ]
-q.heapSort()
-q.print() // [ 8, 7, 6, 5, 4, 3, 2, 1 ]
+export { MinPriorityQueue }

Data-Structures/Heap/test/MinPriorityQueue.test.js

@@ -0,0 +1,36 @@
+import { MinPriorityQueue } from '../MinPriorityQueue'
+
+describe('MinPriorityQueue', () => {
+  const values = [5, 2, 4, 1, 7, 6, 3, 8]
+  const capacity = values.length
+
+  const Queue = new MinPriorityQueue(capacity);
+
+  values.forEach(v => Queue.insert(v))
+
+  it('Check heap ordering', () => {
+    const mockFn = jest.fn()
+    Queue.print(mockFn)
+
+    expect(mockFn.mock.calls.length).toBe(1)    // Expect one call
+    expect(mockFn.mock.calls[0].length).toBe(1) // Expect one argument
+
+    const heap = mockFn.mock.calls[0][0]
+    expect(heap.length).toBe(capacity)
+    expect(heap).toStrictEqual([1, 2, 3, 5, 7, 6, 4, 8])
+  })
+
+  it('heapSort() expected to reverse the heap ordering', () => {
+    Queue.heapSort()
+
+    const mockFn = jest.fn()
+    Queue.print(mockFn)
+
+    expect(mockFn.mock.calls.length).toBe(1)
+    expect(mockFn.mock.calls[0].length).toBe(1)
+
+    const heap = mockFn.mock.calls[0][0]
+    expect(heap.length).toBe(capacity)
+    expect(heap).toStrictEqual([8, 7, 6, 5, 4, 3, 2, 1])
+  })
+})