Test scripts are a set of instructions or commands written tester write to perform the testing process using a tool. Basically, it is a computer program programming language used to automate the testing process. These scripts allow testers to define specific actions, inputs, and expected outcomes for testing an application.

When writing test scripts, testers often make use of testing frameworks or specialized automation tools that provide the functions and methods useful in interacting with the application under test.

We can consider the below example where the Selenium WebDriver, a testing framework, uses Python to automate the testing of a web application. The script opens the web browser, navigates to a specific URL, enters a search query in the input field, clicks the search button, and verifies that the results page is displayed correctly.

from selenium import webdriver

Create a new instance of the Firefox driver

driver = webdriver.Firefox()

Open the application URL

driver.get("https://www.example.com")

Find the search input field and enter a search query

search_input = driver.find_element_by_id("search-input")
search_input.send_keys("test automation")

Submit the search form

search_button = driver.find_element_by_id("search-button")
search_button.click()

Verify that the search results page is displayed

results_page = driver.find_element_by_id("results-page")
assert results_page.is_displayed()

Close the browser

driver.quit()

Advantages of Test Script

Test scripts can save time and effort by automating repetitive tasks and ensuring consistent and reliable testing. Some of the other advantages of test scripts are:

• Test scripts ensure that tests are executed in a consistent and precise manner, and since the instructions are predefined, there is less room for human error or inconsistency in test execution.
• With test scripts, testers can easily achieve higher test coverage, including a wide range of scenarios, edge cases, and user interactions.
• Test scripts can be reused across different projects or iterations, providing a significant advantage.
• Test scripts enable automation of the testing process, reducing the need for manual intervention, which saves time and effort.
• Automated tests can run overnight or in parallel, allowing testers to cover more test cases in a shorter amount of time.
• Test scripts are invaluable for regression testing as running the existing test scripts helps ensure that any modifications in the application have not introduced any unintended side effects or broken functionalities.
• It is easy to share test scripts with your colleagues to increase team collaboration.

Test scripts enable testers to achieve comprehensive test coverage, increase efficiency, save time, and maintain consistent and accurate test execution. These advantages contribute to better software quality, faster release cycles, and improved customer satisfaction.

How to Write a Test Script?

When it comes to writing a test script, there are several key steps to follow. Here's a general outline of the process:

• Identify test scenarios you want to cover. These scenarios represent the application's specific functionalities, features, or use cases.
• Break down each test scenario into individual steps. Test steps are the actions or interactions that testers need to perform to execute the test. They include inputs, expected outputs, and any necessary preconditions or prerequisites.
• Select a test automation tool or framework that suits your needs and testing process. Popular options include Selenium WebDriver, Appium, or Cypress for web applications and Espresso or XCTest for mobile applications.
• Now, write a test script in the programming language of your choice using the chosen test automation tool. It usually involves writing code that interacts with the application, simulating user actions, and making assertions to validate expected outcomes.
• Determine the test data required for testing, which typically includes creating test data sets, defining mock data, or interacting with databases or APIs.
• Identify each test step's expected outcomes and include assertions in your test script to compare the actual results with the expected values.
• Consider potential error scenarios or exceptions that may occur during test execution. And properly implement appropriate error-handling techniques in your test script to handle exceptions and log failures.
• Run the test script on the application or test environment and monitor the execution and debug any issues or failures encountered.
• Maintain good documentation and organize your test scripts to ensure they remain scalable, maintainable, and reusable.

Best Practices to Follow While Writing Test Scripts

While developing and running your test scripts, there are a few best practices to follow that will make the entire process simple for everyone involved.

• Write test scripts that are scalable and reusable.
• Test scripts should have the ability to easily modify with new changes introduced in the application.
• Make sure that the scripts you create are properly maintained.
• Follow the standard naming conventions and regulations practiced in the testing industry.
• Store test data separately from your test scripts to maintain data integrity.
• Ensure that the test scripts are independent of each other, i.e., they are self-contained and don’t rely on the execution or results of other tests.

Example of a Test Script

Let’s take the example of a website's search functionality and filters. The user is trying to search a certain blog title using search and applying different filters to see the results.

Follow the below test steps to validate the search feature and the filters. You can use any automation tool or programming language to write the test script.

• Identify the search box.
• Enter the search query into the search box.
• Click the "Search" button or press Enter to initiate the search.
• Verify that the search results page is displayed.
• Validate that the filter option is available and active.

a. Select a filter option (e.g., price range, brand, category, etc.).
b. Apply the selected filter.
c. Verify that the search results are updated based on the applied filter.
d. Repeat the above steps for multiple filter options.

These steps are basic to check the search and filter functions. You can also perform advanced tests for search and filters, including giving blank inputs, clearing inputs, entering special characters, and providing multiple inputs simultaneously.