Test Classes — DataProvider, Assertions, and TestNG

package com.company.api.tests;

import com.company.api.base.BaseTest;
import com.company.api.endpoints.UserEndpoint;
import com.company.api.pojo.request.CreateUserRequest;
import com.company.api.pojo.response.UserResponse;
import io.qameta.allure.Description;
import io.qameta.allure.Feature;
import io.qameta.allure.Severity;
import io.qameta.allure.SeverityLevel;
import io.restassured.response.Response;
import org.testng.Assert;
import org.testng.annotations.BeforeClass;
import org.testng.annotations.DataProvider;
import org.testng.annotations.Test;

import static org.hamcrest.Matchers.*;

@Feature("User Management")
public class UserTests extends BaseTest {

    private UserEndpoint userEndpoint;

    @BeforeClass
    public void setupEndpoint() {
        userEndpoint = new UserEndpoint(requestSpec);
    }

    @Test(description = "GET /users returns 200 and non-empty list")
    @Severity(SeverityLevel.BLOCKER)
    @Description("Verify that getting all users returns a successful response with data")
    public void testGetAllUsers() {
        userEndpoint.getAllUsers()
            .then()
                .statusCode(200)
                .body("size()", greaterThan(0))
                .body("[0].name", notNullValue());
    }

    @Test(description = "GET /users/{id} returns correct user")
    @Severity(SeverityLevel.CRITICAL)
    public void testGetUserById() {
        Response response = userEndpoint.getUserById(1);

        response.then()
            .statusCode(200)
            .body("id", equalTo(1))
            .body("name", notNullValue())
            .body("email", containsString("@"));
    }

    @Test(description = "POST /users creates a new user")
    @Severity(SeverityLevel.BLOCKER)
    public void testCreateUser() {
        CreateUserRequest request = new CreateUserRequest(
            "Anita Desai", "anita@example.com",
            "9876543210", "SDET"
        );

        Response response = userEndpoint.createUser(request);

        response.then()
            .statusCode(201)
            .body("name", equalTo("Anita Desai"))
            .body("email", equalTo("anita@example.com"))
            .body("id", notNullValue());

        // Deserialize and do further assertions
        UserResponse created = response.as(UserResponse.class);
        Assert.assertTrue(created.getId() > 0, "ID should be positive");
        Assert.assertNotNull(created.getCreatedAt(), "createdAt should be set");
    }

    @Test(description = "GET /users/{id} with invalid ID returns 404")
    @Severity(SeverityLevel.NORMAL)
    public void testGetNonExistentUser() {
        userEndpoint.getUserById(99999)
            .then()
                .statusCode(404);
    }

    @Test(description = "DELETE /users/{id} removes the user")
    @Severity(SeverityLevel.CRITICAL)
    public void testDeleteUser() {
        // Setup — create a user to delete
        CreateUserRequest request = new CreateUserRequest(
            "Temp User", "temp@example.com",
            "9000000000", "Contractor"
        );
        UserResponse created = userEndpoint.createUserAndGet(request);

        // Act — delete the user
        userEndpoint.deleteUser(created.getId())
            .then()
                .statusCode(204);

        // Verify — user should no longer exist
        userEndpoint.getUserById(created.getId())
            .then()
                .statusCode(404);
    }
}

package com.company.api.tests;

import com.company.api.base.BaseTest;
import com.company.api.endpoints.UserEndpoint;
import com.company.api.pojo.request.CreateUserRequest;
import org.testng.annotations.BeforeClass;
import org.testng.annotations.DataProvider;
import org.testng.annotations.Test;

import static org.hamcrest.Matchers.equalTo;

public class UserDataDrivenTests extends BaseTest {

    private UserEndpoint userEndpoint;

    @BeforeClass
    public void setupEndpoint() {
        userEndpoint = new UserEndpoint(requestSpec);
    }

    @DataProvider(name = "validUsers")
    public Object[][] validUserData() {
        return new Object[][] {
            { "Rahul Sharma", "rahul@example.com", "9876543210", "QA Lead" },
            { "Priya Patel", "priya@example.com", "8765432109", "SDET" },
            { "Amit Kumar", "amit@example.com", "7654321098", "Dev Lead" }
        };
    }

    @DataProvider(name = "invalidEmails")
    public Object[][] invalidEmailData() {
        return new Object[][] {
            { "" },
            { "notanemail" },
            { "missing@" },
            { "@nodomain.com" },
            { "spaces in@email.com" }
        };
    }

    @Test(dataProvider = "validUsers",
          description = "POST /users with valid data returns 201")
    public void testCreateUserWithValidData(
            String name, String email, String phone, String job) {

        CreateUserRequest request =
            new CreateUserRequest(name, email, phone, job);

        userEndpoint.createUser(request)
            .then()
                .statusCode(201)
                .body("name", equalTo(name))
                .body("email", equalTo(email));
    }

    @Test(dataProvider = "invalidEmails",
          description = "POST /users with invalid email returns 400")
    public void testCreateUserWithInvalidEmail(String badEmail) {
        CreateUserRequest request = new CreateUserRequest(
            "Test User", badEmail, "9876543210", "Tester"
        );

        userEndpoint.createUser(request)
            .then()
                .statusCode(400);
    }
}

@Test(groups = {"smoke"}, description = "GET /users returns 200")
public void testGetAllUsers() { ... }

@Test(groups = {"smoke", "regression"}, description = "POST /users creates user")
public void testCreateUser() { ... }

@Test(groups = {"regression"}, description = "PUT /users/{id} updates user")
public void testUpdateUser() { ... }

@Test(groups = {"regression", "negative"}, description = "Invalid email returns 400")
public void testInvalidEmail() { ... }