solution

cypress/e2e/signIn.cy.js

@@ -1,11 +1,96 @@
-/// <reference types="cypress" />
+/// <reference types='cypress' />
 
 describe('Sign In page', () => {
+  const login = 'tomsmith';
+  const pass = 'SuperSecretPassword!';
+  const rightSite = 'https://the-internet.herokuapp.com/secure';
+  const mainSite = 'https://the-internet.herokuapp.com/login';
+
   beforeEach(() => {
+    cy.visit(mainSite);
+  });
+
+  describe('Site contents', () => {
+    it('should contain "Login Page" in header', () => {
+      cy.get('h2').should('have.text', 'Login Page');
+    });
+
+    it('should contain instruction in subheader', () => {
+      cy.get('h4')
+        .invoke('text')
+        .should((text) => {
+          expect(text.length).to.be.greaterThan(50);
+        });
+    });
+
+    it('should have a "Login" button', () => {
+      cy.get('.radius')
+        .should('have.text', ' Login')
+        .and('exist')
+        .and('be.visible')
+        .and('have.attr', 'type', 'submit');
+    });
+  });
+
+  describe('Valid login', () => {
+    beforeEach(() => {
+      cy.get('#username').type(login);
+      cy.get('#password').type(pass);
+    });
+
+    it('should login with valid data', () => {
+      cy.get('form').find('button[type="submit"]').click();
+    });
+
+    it('should return code 200 for POST method', () => {
+      cy.request({
+        method: 'POST',
+        url: 'https://the-internet.herokuapp.com/authenticate',
+        body: { username: login, password: pass }
+      }).then((response) => {
+        expect(response.status).to.eq(200);
+      });
+    });
+
+    it('should redirect to the correct site', () => {
+      cy.get('form').find('button[type="submit"]').click();
+      cy.url().should('eq', rightSite);
+    });
+  });
+
+  describe('Invalid login', () => {
+    it('should display error message for invalid login', () => {
+      cy.get('#username').type('tommssmith');
+      cy.get('#password').type(pass);
+      cy.get('form').find('button[type="submit"]').click();
+
+      cy.get('#flash')
+        .should('be.visible')
+        .and('contain', 'Your username is invalid!');
+    });
+
+    it(`should display error message for valid login
+       but invalid password`, () => {
+      cy.get('#username').type(login);
+      cy.get('#password').type('randompassword');
+      cy.get('form').find('button[type="submit"]').click();
 
+      cy.get('#flash')
+        .should('be.visible')
+        .and('contain', 'Your password is invalid!');
+    });
   });
 
-  it('', () => {
+  describe('User Logout', () => {
+    beforeEach(() => {
+      cy.get('#username').type(login);
+      cy.get('#password').type(pass);
+      cy.get('form').find('button[type="submit"]').click();
+    });
 
+    it('should properly log out user', () => {
+      cy.get('.button').click();
+      cy.url().should('eq', mainSite);
+    });
   });
 });