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

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 }

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)
+  })
+})