Why UI Automation Is Challenging
UI automation has always been a complex task due to various factors:
- Validating diverse UI components and behaviors
- Handling dynamic structures and changing content
- Managing asynchronous operations
This complexity often results in unstable tests — tests that pass or fail inconsistently. When UI tests become unreliable, they demand significant manual intervention to determine if a failure is genuine and to investigate its cause. This leads to wasted time and effort, especially when tests fail sporadically without any code changes.
What Are Flaky Tests?
Flaky tests are tests that yield different results across runs even when no code changes have occurred. They might pass in one run and fail in the next, making debugging difficult and eroding trust in automated test suites. Flaky tests are a major reason why QA teams hesitate to fully rely on UI automation.
Common Causes of Flaky Tests
As engineering teams grow and development accelerates, the demand for automation increases. However, the more tests that are automated, the more likely some will become flaky. Here are common culprits:
1️⃣ Poor Locator Strategies
Locators are essential for identifying and interacting with UI elements.
Examples include:
XPath
ID
Class name
CSS selectors
Custom attributes like data-test-id
Incorrect or unstable locators (e.g., dynamic IDs, auto-generated class names) often lead to flaky tests, especially in applications with frequently changing UIs.
2️⃣ Parallel Execution Issues
Concurrency problems can occur when tests run in parallel but depend on shared data or sequences.
Example:
A login test dependent on a sign-up test may fail if it runs before user creation.
Two tests accessing or modifying the same data row may interfere with each other.
Without careful test planning, parallel execution can introduce flakiness.
3️⃣ Async Operations and Timing
Async operations like file uploads or API requests may take variable time to complete. Tests that don’t handle this variability properly (e.g., lacking dynamic waits) often fail intermittently.
4️⃣ Test Environment Instability
Tests that pass locally may become flaky in CI/CD pipelines due to:
- Performance degradation under load
- Interference from other tests modifying shared data
- External factors like browser or WebDriver updates
How to Prevent Flaky UI Tests
- ✅ Use Stable Locators
Choose locators that are less likely to change:
- Avoid dynamic IDs or auto-generated classes.
- Prefer relative XPaths over absolute XPaths.
- ✅ Plan Tests for Independence
Ensure each test case is self-contained with independent test data.
Avoid data dependencies between tests (e.g., don’t rely on a sign-up test to create a user for a login test).
- ✅ Shorten and Modularize Tests
Break down long end-to-end scenarios into smaller, focused tests:
- Validate individual components separately.
- Use APIs or database scripts for setup rather than UI flows in every test.
Example: For checkout page validation:
- Perform login via UI.
- Add items to cart via API.
- Load checkout page for validation.
✅ Manage Test Data Carefully
Create and clean up data before and after each test using APIs or database scripts.
Separate test environments can help isolate performance/load tests from functional tests.
✅ Use On-Demand Test Environments
Spin up fresh environments per PR or test cycle using containers like Docker. This ensures isolation, reduces environment-related flakiness, and provides consistent test conditions.
How DevAssure Minimizes Flaky Tests
DevAssure is an AI-powered no-code UI test automation platform designed to help teams build stable, reliable tests with minimal effort. Here’s how it addresses flakiness:
🔹 Intelligent Locator Strategy:
Users can define locator preferences to guide how DevAssure’s recorder selects locators.
DevAssure automatically generates backup locators, ensuring that if the primary locator fails, execution can continue using alternatives.
🔹 Run Tests Anywhere:
DevAssure tests can execute locally, in the cloud, or in Docker containers via its powerful CLI, offering flexibility and consistency.
🔹 Interleave API and Database Steps:
DevAssure allows mixing API/database operations with UI steps:
Prepare test data through APIs.
Validate test outcomes through API responses or DB queries instead of UI assertions alone.
🔹 Pre/Post Hooks for Data Management:
Built-in hooks let you seed or clean up test data before and after each test run, improving isolation and stability.
🔹 Advanced Wait Mechanisms:
Configurable implicit and explicit waits, along with advanced polling for async operations, ensure your tests handle timing variability reliably.
Experience DevAssure’s Stability Advantage
DevAssure guarantees 99.99% stability for UI tests, reducing flakiness and improving trust in automation results.
To know more about how DevAssure can help in eliminating flakiness, please click here to schedule a demo with our team of experts.