Add basic E2E tests.

assets/js/admin.js

@@ -220,7 +220,7 @@
 
 			if (input.name === 'email') {
 				if (!input.value.includes('@') || !input.value.includes('.'))
-					return params.invalid_email;
+					return params.invalid_email_error;
 				if (input.value !== $('#mailchimp-sf-profile-details input#confirm_email').val())
 					return params.confirm_email_match;
 			}

tests/cypress/e2e/admin.test.js

@@ -19,4 +19,42 @@ describe('Admin can login and make sure plugin is activated', () => {
 		cy.get('#adminmenu li#toplevel_page_mailchimp_sf_options').click();
 		cy.get('#wpbody .mailchimp-header h1').contains('Mailchimp List Subscribe Form');
 	});
+
+	it('Admin can see "Create account" button and Can visit "Create account" settings page.', () => {
+		cy.visit('/wp-admin/admin.php?page=mailchimp_sf_options');
+
+		// Check Create account button.
+		cy.get('#mailchimp_sf_create_account_button').should('be.visible');
+		cy.get('#mailchimp_sf_create_account_button').contains('Create account');
+
+		cy.get('#mailchimp_sf_create_account_button').click();
+		cy.get('#mailchimp-sf-create-account .title').contains('Confirm your information');
+		cy.get('#mailchimp-sf-create-activate-account').should('be.visible');
+	});
+
+	it("Admin shouldn't able to submit create account form with invalid data", () => {
+		cy.visit('/wp-admin/admin.php?page=mailchimp_sf_create_account');
+
+		// Submit form without filling any data.
+		cy.get('#mailchimp-sf-create-activate-account').click();
+
+		// Check error messages.
+		cy.get('#mailchimp-sf-first_name-error').contains("First name can't be blank.");
+		cy.get('#mailchimp-sf-last_name-error').contains("Last name can't be blank.");
+		cy.get('#mailchimp-sf-email-error').contains(
+			'Email confirmation must match confirmation email.',
+		);
+		cy.get('#mailchimp-sf-confirm_email-error').contains(
+			'Email confirmation must match the field above.',
+		);
+		cy.get('#mailchimp-sf-address-error').contains("Address line 1 can't be blank.");
+		cy.get('#mailchimp-sf-city-error').contains("City can't be blank.");
+		cy.get('#mailchimp-sf-state-error').contains("State can't be blank.");
+		cy.get('#mailchimp-sf-zip-error').contains("Zip can't be blank.");
+
+		cy.get('#email').clear().type('test');
+		cy.get('#confirm_email').clear().type('test');
+		cy.get('#mailchimp-sf-create-activate-account').click();
+		cy.get('#mailchimp-sf-email-error').contains('Insert correct email.');
+	});
 });