Synthetic Test Scripts

Synthetic Test Scripts are pre-written, automated tests that simulate user behavior to evaluate software performance and functionality. They are often used for performance testing, monitoring, and regression testing.

Detailed explanation

Synthetic test scripts, also known as synthetic transactions or scripted tests, are automated test cases designed to mimic the actions of real users interacting with a software application. Unlike real user monitoring (RUM), which passively collects data from actual user sessions, synthetic testing proactively simulates user activity to identify potential issues before they impact real users. This proactive approach makes synthetic testing invaluable for performance monitoring, regression testing, and pre-production testing.

The core idea behind synthetic test scripts is to create a controlled and repeatable environment where specific user flows can be executed and measured. This allows testers and developers to isolate performance bottlenecks, identify functional defects, and ensure that the application meets its performance and reliability goals.

Practical Implementation:

Creating effective synthetic test scripts involves several key steps:

  1. Identify Critical User Flows: The first step is to identify the most important user flows within the application. These are the flows that are most frequently used, most critical to the business, or most likely to experience performance issues. Examples include user login, product search, checkout process, and form submission.

  2. Design the Test Script: Once the critical flows are identified, the next step is to design the test script. This involves defining the specific steps that the script will execute, the data that it will use, and the expected results. The script should be designed to accurately simulate the behavior of a real user, including realistic delays and think times.

  3. Choose a Testing Tool: Several tools are available for creating and executing synthetic test scripts. Popular options include Selenium, JMeter, Gatling, and LoadRunner. The choice of tool will depend on the specific requirements of the project, such as the type of application being tested, the desired level of automation, and the available budget.

  4. Implement the Test Script: The next step is to implement the test script using the chosen testing tool. This involves writing the code that will execute the steps defined in the test script design. The code should be well-documented and easy to maintain.

  5. Execute the Test Script: Once the test script is implemented, it can be executed to simulate user activity. The testing tool will typically provide metrics on response time, throughput, error rates, and other performance indicators.

  6. Analyze the Results: The final step is to analyze the results of the test execution. This involves identifying any performance bottlenecks or functional defects that were uncovered during the test. The results should be documented and shared with the development team so that they can be addressed.

Code Example (Selenium with Python):

from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
 
# Initialize the webdriver (e.g., Chrome)
driver = webdriver.Chrome()
 
# Navigate to the application URL
driver.get("https://www.example.com")
 
# Find the search input field and enter a search term
search_input = driver.find_element(By.ID, "search-input")
search_input.send_keys("product name")
 
# Submit the search form
search_input.submit()
 
# Wait for the search results to load
try:
    WebDriverWait(driver, 10).until(
        EC.presence_of_element_located((By.ID, "search-results"))
    )
except:
    print("Search results did not load within 10 seconds")
 
# Verify that the search results are displayed
search_results = driver.find_element(By.ID, "search-results")
assert search_results.is_displayed()
 
# Close the browser
driver.quit()

This example demonstrates a simple synthetic test script that simulates a user searching for a product on a website. The script uses Selenium to automate the browser interaction, including navigating to the website, entering a search term, submitting the search form, and verifying that the search results are displayed.

Best Practices:

  • Realistic User Simulation: Ensure that the test scripts accurately simulate the behavior of real users, including realistic delays and think times. This will help to ensure that the test results are representative of real-world performance.
  • Data Variation: Use a variety of data in the test scripts to ensure that the application is thoroughly tested. This includes using different search terms, different user accounts, and different input values.
  • Regular Maintenance: Regularly maintain the test scripts to ensure that they are up-to-date with the latest changes to the application. This will help to prevent false positives and ensure that the test results are accurate.
  • Monitoring and Alerting: Set up monitoring and alerting to automatically detect performance issues and functional defects. This will allow you to quickly identify and resolve problems before they impact real users.
  • Integration with CI/CD: Integrate synthetic testing into the continuous integration and continuous delivery (CI/CD) pipeline. This will help to ensure that new code changes are thoroughly tested before they are deployed to production.

Common Tools:

  • Selenium: A popular open-source framework for automating web browsers.
  • JMeter: An open-source load testing tool that can be used to simulate a large number of concurrent users.
  • Gatling: An open-source load testing tool that is designed for high-performance testing.
  • LoadRunner: A commercial load testing tool that provides a wide range of features and capabilities.
  • New Relic Synthetics: A cloud-based synthetic monitoring tool that allows you to create and execute synthetic test scripts from multiple locations around the world.
  • Datadog Synthetic Monitoring: Similar to New Relic, Datadog offers synthetic monitoring capabilities as part of its broader monitoring platform.

In conclusion, synthetic test scripts are a powerful tool for proactively identifying and resolving performance issues and functional defects in software applications. By simulating user activity in a controlled and repeatable environment, synthetic testing helps to ensure that applications meet their performance and reliability goals and provide a positive user experience.

Further reading

Related Terms

A/B Testing

Acceptance Testing

Accessibility Tester