Good Practices and Strategies for Data Setup in Test Automation

A fundamental challenge in test automation, particularly for regression tests, is data setup. The manner in which test data is organized, populated, and managed can significantly influence the reliability and efficiency of automated tests. Let's explore some of the prevalent strategies and best practices for test data setup and the pros and cons of each.

1. Database Restore to a Known State:

Before running the automated tests, restore the database to a known state using database backups or checkpoints. This ensures that the data environment remains consistent for every test run.

The typical way of doing this is by running an SQL script using a DBMS-specific tool.

Pros:

• Consistency: Ensures every test starts from the same data state.

• Simplified Debugging: With a known state, it’s easier to debug failing tests.

Cons:

• Time-consuming: Restoring a large database might take significant time, checkpoints are faster for large databases.

• Static Data: If the tests need variations in data, this method might not be optimal.

2. setUp() and tearDown() mechanisms:

Before each test case runs, the setUp() object sets up the required data environment, and once the test completes, the tearDown() object cleans up or resets the data. This data can be generated on-the-fly based on defined templates using DataProviders. Furthermore, Test Suite object has properties to set procedures as setup and teardown objects. Similar behavior can be achieved by calling these types of initialization objects at the beginning and the end of the test source code.

Pros:

• Flexibility: Allows each test to have its own tailored data setup.

• Isolation: Ensures that tests don't interfere with each other's data.

Cons:

• Overhead: Setting up and tearing down for each test might add overhead.

• Complexity: Requires careful management of setup and cleanup processes.

Examples

The test requires a Customer with Id = 100 and no purchases made, so at the beginning of the test this can be set:

For each Customer
    where CustomerId = 100
when none
    New 
        CustomerId = 100
        CustomerEmail = "testUser@company.com"
    endnew
endfor

For each Purchase
   where CustomerId = 100
   delete
endfor

3. Mocking Database:

Instead of interacting with real databases or data sources, use mocks and stubs to simulate the data behavior. This mechanism is very interesting when the procedure has a complex logic and data can vary significantly on each test run. You can read more about this here

Pros:

• Speed: Tests run faster as they don’t interact with actual data sources.
• Isolation: Tests are isolated from external data dependencies.

Cons

• Limited Scope: May not cover issues that arise from real data interactions.
• Maintenance: Mocks and stubs can become outdated and might require frequent updates.

Conclusion

The choice of test data setup strategy often depends on the application's nature, the testing requirements, and the existing infrastructure. For some, restoring a database might be efficient, while for others, dynamic data generation or mocking could be more appropriate. It's crucial to regularly evaluate the chosen strategy's effectiveness in ensuring that test automation remains robust, efficient, and reliable. Remember, the ultimate goal is to have high confidence in the test results, and the right data setup strategy plays a pivotal role in achieving that.

 

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Recommended references

• Regression Testing Blog
• Validating Data - Blog
• Test Automation Patterns- Blog
• Restoring database in Jenkins example (Blog)