refactor(tests): extract common parts of login test cases into beforeEach

cypress/e2e/login.cy.ts

@@ -5,20 +5,19 @@ import LoginPage from '../support/pageObjects/LoginPage';
 describe('Login Page', () => {
   const loginPage = new LoginPage();
 
-  it('should successfully log in with correct credentials', () => {
+  beforeEach(() => {
     loginPage.visit();
     loginPage.getUsernameInput().should('be.visible');
     loginPage.getPasswordInput().should('be.visible');
     loginPage.getSubmitButton().should('be.visible');
+  });
+
+  it('should successfully log in with correct credentials', () => {
     loginPage.login('admin', '123456');
     cy.contains('登录成功').should('be.visible', { timeout: 10000 });
   });
 
   it('should show an error message for incorrect credentials', () => {
-    loginPage.visit();
-    loginPage.getUsernameInput().should('be.visible');
-    loginPage.getPasswordInput().should('be.visible');
-    loginPage.getSubmitButton().should('be.visible');
     loginPage.login('wronguser', 'wrongpassword');
     cy.contains('登录失败').should('be.visible', { timeout: 10000 });
   });