Stack 👗

Author: deadcoder0904

examples/datastructures/stack.js

@@ -0,0 +1,36 @@
+class Stack {
+	constructor() {
+		this.dataStore = [];
+		this.top = -1;
+	}
+
+	push(element) {
+		this.top++;
+		this.dataStore.push(element);
+	}
+
+	pop() {
+		this.top--;
+		return this.dataStore.pop();
+	}
+
+	peek() {
+		return this.dataStore[this.top];
+	}
+
+	clear() {
+		if(~this.top)
+			while(this.top--)
+				this.dataStore.pop();
+	}
+
+	empty() {
+		return !~this.top;
+	}
+
+	length() {
+		return this.top + 1;
+	}
+}
+
+module.exports = Stack;

test/datastructures/stack.test.js

@@ -0,0 +1,70 @@
+const expect = require('chai').expect;
+const Stack = require('../../examples/datastructures/stack');
+
+describe('=> STACK', function() {
+	let numbers;
+	before(function () {
+		numbers = new Stack();
+	});
+
+	it('should create an Empty Stack', function(done) {
+		expect(numbers.dataStore).to.deep.equal([]);
+		expect(numbers.top).to.equal(-1);
+		done();
+	});
+
+	it('should push elements into the Stack', function(done) {
+		numbers.push(1);
+		numbers.push(2);
+		numbers.push(3);
+		numbers.push(4);
+		expect(numbers.dataStore).to.deep.equal([1,2,3,4]);
+		expect(numbers.top).to.equal(3);
+		done();
+	});
+
+	describe('=> pop', function() {
+
+		it('should pop 1 element of the Stack', function(done) {
+			numbers.pop();
+			expect(numbers.dataStore).to.deep.equal([1,2,3]);
+			expect(numbers.top).to.equal(2);
+			done();
+		});
+
+		it('should pop all elements of the Stack', function(done) {
+			numbers.pop();
+			numbers.pop();
+			numbers.pop();
+			expect(numbers.dataStore).to.deep.equal([]);
+			expect(numbers.top).to.equal(-1);
+			done();
+		});
+
+	});
+
+	it('should peek the Stack', function(done) {
+		expect(numbers.peek()).to.deep.equal(4);
+		done();
+	});
+
+	it('should check if the Stack is empty', function(done) {
+		expect(numbers.empty()).to.equal(false);
+		done();
+	});
+
+	it('should check the length of the Stack', function(done) {
+		expect(numbers.length()).to.equal(4);
+		done();
+	});
+
+	describe('=> clear', function() {
+		it('should clear the Stack', function(done) {
+				numbers.clear();
+				expect(numbers.top).to.equal(-1);
+				expect(numbers.dataStore).to.deep.equal([]);
+				done();
+			});
+	});
+
+});