From 449ef451937f5e02aa960e7085a9f5f35d192e92 Mon Sep 17 00:00:00 2001
From: Eric Lavault <39483232+lvlte@users.noreply.github.com>
Date: Sun, 10 Oct 2021 16:25:41 +0200
Subject: [PATCH] Data Structure : Convert live test to Jest test. Remove live
 code & console.log

---
 Data-Structures/Heap/MinPriorityQueue.js      | 19 ++--------
 .../Heap/test/MinPriorityQueue.test.js        | 36 +++++++++++++++++++
 Data-Structures/Queue/QueueUsing2Stacks.js    | 34 ++++++------------
 .../Queue/test/QueueUsing2Stacks.test.js      | 15 ++++++++
 4 files changed, 65 insertions(+), 39 deletions(-)
 create mode 100644 Data-Structures/Heap/test/MinPriorityQueue.test.js
 create mode 100644 Data-Structures/Queue/test/QueueUsing2Stacks.test.js

diff --git a/Data-Structures/Heap/MinPriorityQueue.js b/Data-Structures/Heap/MinPriorityQueue.js
index 0b52ca65d..40b014a86 100644
--- a/Data-Structures/Heap/MinPriorityQueue.js
+++ b/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 }
diff --git a/Data-Structures/Heap/test/MinPriorityQueue.test.js b/Data-Structures/Heap/test/MinPriorityQueue.test.js
new file mode 100644
index 000000000..320ad6783
--- /dev/null
+++ b/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])
+  })
+})
diff --git a/Data-Structures/Queue/QueueUsing2Stacks.js b/Data-Structures/Queue/QueueUsing2Stacks.js
index 6218688ef..130a8c13a 100644
--- a/Data-Structures/Queue/QueueUsing2Stacks.js
+++ b/Data-Structures/Queue/QueueUsing2Stacks.js
@@ -12,53 +12,41 @@ class Queue {
     this.inputStack.push(item)
   }
 
-  dequeue (item) {
+  dequeue () {
     // push all items to outputstack
     this.outputStack = []
-    if (this.inputStack.length > 0) {
-      while (this.inputStack.length > 0) {
-        this.outputStack.push(this.inputStack.pop())
-      }
+    while (this.inputStack.length > 0) {
+      this.outputStack.push(this.inputStack.pop())
     }
-    // display the top element of the outputstack
+    // return the top element of the outputstack if any
     if (this.outputStack.length > 0) {
-      console.log(this.outputStack.pop())
+      const top = this.outputStack.pop()
       // repush all the items to the inputstack
       this.inputStack = []
       while (this.outputStack.length > 0) {
         this.inputStack.push(this.outputStack.pop())
       }
+      return top
     }
   }
 
   // display elements of the inputstack
-  listIn () {
+  listIn (output = value => console.log(value)) {
     let i = 0
     while (i < this.inputStack.length) {
-      console.log(this.inputStack[i])
+      output(this.inputStack[i])
       i++
     }
   }
 
   // display element of the outputstack
-  listOut () {
+  listOut (output = value => console.log(value)) {
     let i = 0
     while (i < this.outputStack.length) {
-      console.log(this.outputStack[i])
+      output(this.outputStack[i])
       i++
     }
   }
 }
 
-// testing
-
-const queue = new Queue()
-queue.enqueue(1)
-queue.enqueue(2)
-queue.enqueue(8)
-queue.enqueue(9)
-
-console.log(queue.dequeue())
-// ans = 1
-console.log(queue.dequeue())
-// ans = 2
+export { Queue }
diff --git a/Data-Structures/Queue/test/QueueUsing2Stacks.test.js b/Data-Structures/Queue/test/QueueUsing2Stacks.test.js
new file mode 100644
index 000000000..06f26a6d8
--- /dev/null
+++ b/Data-Structures/Queue/test/QueueUsing2Stacks.test.js
@@ -0,0 +1,15 @@
+import { Queue } from '../QueueUsing2Stacks'
+
+describe('QueueUsing2Stacks', () => {
+  const queue = new Queue()
+
+  it('Check enqueue/dequeue', () => {
+    queue.enqueue(1)
+    queue.enqueue(2)
+    queue.enqueue(8)
+    queue.enqueue(9)
+
+    expect(queue.dequeue()).toBe(1)
+    expect(queue.dequeue()).toBe(2)
+  })
+})