Dependency between tests in Selenium Java - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Why avoid dependencies between tests?

In Selenium test automation, why is it important to avoid dependencies between tests?

A Because dependent tests can cause cascading failures making debugging harder.

B Because dependent tests reduce the need for setup and teardown methods.

C Because dependent tests run faster and improve performance.

D Because dependent tests always pass regardless of application state.

💡 Hint

Think about what happens if one test fails and others rely on it.

Tests that depend on each other can cause multiple failures if one test fails, making it difficult to find the root cause. Independent tests improve reliability and ease debugging.

❓ Predict Output

intermediate

Test execution order with dependencies

Given the following Selenium Java test methods with TestNG annotations, what will be the output when running the test suite?

Selenium Java

import org.testng.annotations.Test;

public class SampleTest {

    @Test(dependsOnMethods = {"testLogin"})
    public void testDashboard() {
        System.out.println("Dashboard test executed");
    }

    @Test
    public void testLogin() {
        System.out.println("Login test executed");
    }

    @Test(dependsOnMethods = {"testDashboard"})
    public void testSettings() {
        System.out.println("Settings test executed");
    }
}

A

Settings test executed
Dashboard test executed
Login test executed

B

Dashboard test executed
Login test executed
Settings test executed

C

Login test executed
Settings test executed
Dashboard test executed

D

Login test executed
Dashboard test executed
Settings test executed

💡 Hint

Tests run after their dependencies have run successfully.

testLogin runs first because others depend on it. Then testDashboard runs, followed by testSettings which depends on testDashboard.

❓ assertion

advanced

Assertion failure impact on dependent tests

Consider these TestNG tests where testLogin fails due to an assertion error. What happens to testDashboard which depends on testLogin?

Selenium Java

import org.testng.Assert;
import org.testng.annotations.Test;

public class LoginTests {

    @Test
    public void testLogin() {
        Assert.assertTrue(false, "Login failed");
    }

    @Test(dependsOnMethods = {"testLogin"})
    public void testDashboard() {
        System.out.println("Dashboard test executed");
    }
}

A testDashboard runs before testLogin.

B testDashboard is skipped because testLogin failed.

C testDashboard runs and fails due to testLogin failure.

D testDashboard runs and passes despite testLogin failure.

💡 Hint

Think about how TestNG handles dependencies when a test fails.

If a test that others depend on fails, TestNG skips the dependent tests to avoid false failures.

🔧 Debug

advanced

Fix the flaky test caused by dependency

These two Selenium tests depend on each other causing flaky failures. Identify the main problem and select the best fix.

Selenium Java

import org.testng.annotations.Test;

public class FlakyTests {

    @Test(dependsOnMethods = {"testAddItem"})
    public void testCheckout() {
        System.out.println("Checkout test executed");
    }

    @Test(dependsOnMethods = {"testCheckout"})
    public void testAddItem() {
        System.out.println("Add item test executed");
    }
}

A Keep dependencies as is; TestNG will handle circular dependencies automatically.

B Add a third test that both depend on to fix the order.

C Remove the dependency from testAddItem on testCheckout to break the circular dependency.

D Change both tests to run in parallel to avoid dependency issues.

💡 Hint

Look for circular dependencies and how they affect test execution.

There is a circular dependency between testAddItem and testCheckout causing flaky runs. Removing one dependency breaks the cycle and stabilizes tests.

❓ framework

expert

Best practice for managing test dependencies in Selenium with TestNG

Which approach is best to manage dependencies between Selenium tests in TestNG to ensure reliable and maintainable test suites?

A Design tests to be independent and use setup methods to prepare required state instead of relying on other tests.

B Use <code>dependsOnMethods</code> extensively to control test order and share state between tests.

C Combine multiple test scenarios into one large test to avoid dependencies.

D Disable tests that fail due to dependencies and rerun them manually later.

💡 Hint

Think about test reliability and ease of maintenance.

Independent tests with proper setup and teardown are more reliable and easier to maintain than tests relying on dependencies which cause fragility.

Practice

1. What is the main purpose of using dependsOnMethods in Selenium Java tests?

easy

A. To skip tests that have no assertions

B. To run all tests in parallel regardless of order

C. To automatically retry failed tests

D. To make one test run only after another test has passed

Solution

1. Step 1: Understand test dependencies

   The dependsOnMethods attribute is used to specify that a test should run only after another test method has successfully completed.

2. Step 2: Recognize the effect on test execution order

   This ensures that dependent tests do not run if the test they depend on fails, maintaining logical test flow.

3. Final Answer:

   To make one test run only after another test has passed -> Option D

4. Quick Check:

   dependsOnMethods controls test order and dependency [OK]

Hint: dependsOnMethods links tests to run in sequence [OK]

Common Mistakes:

• Thinking dependsOnMethods runs tests in parallel
• Assuming it retries failed tests automatically
• Believing it skips tests without assertions

2. Which of the following is the correct syntax to make testB depend on testA in TestNG?

easy

A. @Test(dependsOnMethods = testA) public void testB() {}

B. @Test(dependsOnMethods = {"testA"}) public void testB() {}

C. @Test(dependsOn = "testA") public void testB() {}

D. @Test(dependOn = "testA") public void testB() {}

Solution

1. Step 1: Recall TestNG annotation syntax

   The correct attribute name is dependsOnMethods and it expects an array of method names as strings.

2. Step 2: Check the syntax correctness

   @Test(dependsOnMethods = {"testA"}) public void testB() {} correctly uses @Test(dependsOnMethods = {"testA"}) with the method name in quotes inside braces.

3. Final Answer:

   @Test(dependsOnMethods = {"testA"}) public void testB() {} -> Option B

4. Quick Check:

   dependsOnMethods requires string array syntax [OK]

Hint: Use dependsOnMethods with braces and quotes [OK]

Common Mistakes:

• Using dependsOn instead of dependsOnMethods
• Omitting quotes around method name
• Not using braces for the array

3. Given the following TestNG code:

@Test
public void login() { Assert.assertTrue(false); }

@Test(dependsOnMethods = {"login"})
public void dashboard() { System.out.println("Dashboard loaded"); }

What will happen when these tests run?

medium

A. login fails, dashboard is skipped

B. login fails, dashboard runs and prints message

C. Both login and dashboard run and pass

D. login passes, dashboard is skipped

Solution

1. Step 1: Analyze login test result

   The login test asserts false, so it will fail.

2. Step 2: Understand effect on dependent test

   The dashboard test depends on login. Since login failed, dashboard will be skipped and not run.

3. Final Answer:

   login fails, dashboard is skipped -> Option A

4. Quick Check:

   Dependent tests skip if dependency fails [OK]

Hint: Failed dependency causes dependent test to skip [OK]

Common Mistakes:

• Assuming dependent test runs despite failure
• Thinking both tests pass
• Confusing skip with fail

4. Identify the error in this TestNG test dependency code:

@Test(dependsOnMethods = "setup")
public void testFeature() {}

@Test
public void setup() {}

medium

A. setup method must be private

B. testFeature should not depend on setup

C. dependsOnMethods should be an array of strings, not a single string

D. setup method must have parameters

Solution

1. Step 1: Check dependsOnMethods syntax

   The attribute dependsOnMethods requires an array of method names, even if only one method is listed.

2. Step 2: Identify the syntax mistake

   Here, dependsOnMethods = "setup" is a single string, missing braces to make it an array.

3. Final Answer:

   dependsOnMethods should be an array of strings, not a single string -> Option C

4. Quick Check:

   dependsOnMethods needs braces for method names [OK]

Hint: Always use braces {} for dependsOnMethods even if one method [OK]

Common Mistakes:

• Using single string instead of string array
• Making dependent method private
• Adding parameters to setup method unnecessarily

5. You have three tests: init(), login(), and purchase(). login() depends on init(), and purchase() depends on login(). If init() fails, what happens when you run all tests together?

hard

A. init fails, login and purchase are skipped

B. init fails, login runs but purchase is skipped

C. init fails, login and purchase run anyway

D. init fails, only purchase runs

Solution

1. Step 1: Understand the dependency chain

   login depends on init, and purchase depends on login, forming a chain: init -> login -> purchase.

2. Step 2: Analyze failure impact

   If init fails, login will be skipped because it depends on init. Since login is skipped, purchase will also be skipped because it depends on login.

3. Final Answer:

   init fails, login and purchase are skipped -> Option A

4. Quick Check:

   Failure cascades down dependent tests [OK]

Hint: Failure in first test skips all dependent tests down the chain [OK]

Common Mistakes:

• Assuming dependent tests run despite failure
• Thinking only immediate dependent test skips
• Believing tests run independently