Task: Implement Developer Tests
Implement one or more tests that enable the validation of the individual software components through execution.
Disciplines: Development
Purpose
Prepare to validate a software component (e.g. an operation, a class, a stored procedure) through unit testing. The result is one or more new developer tests.
Relationships
RolesPrimary Performer: Additional Performers:
InputsMandatory: Optional:
Outputs
Main Description

Developer testing is different from other forms of testing in that it is based on the expected behavior of code units rather than being directly based on the system requirements.

It is best to do this at a small scale, much smaller than the complete code base to be authored by a developer over the course of an iteration. This can be done for one operation, one field added to a user interface, one stored procedure, etc. As the code base is incrementally built, new tests will be authored and existing tests might be revisited to test additional behavior.

Steps
Refine scope and identify the test(s)

Select the increment of work to be tested and identify developer test(s) to verify that the Implementation being developed behaves correctly. One source for the expected behavior for a software component is the Design

In identifying the tests or in any other part of this task, consider collaborating with a Tester who should be well-versed in the issues of testing.

Write the test setup
To successfully run a test the system must be in a known state so that the correct behavior can be defined. Implement the setup logic that must be performed as part of the Developer Test.
Define the expected results

Define the expected results of each test so that it can be verified.

After a test runs, you need to be able to compare the results of running the test against what was expected to happen. The test is successful when the actual results match the expected results.

Write the test logic
Write the steps that perform the actual test(s).
Define the test response
Define the information the test(s) must produce to successfully indicate success or failure. Consider if a response of True or False is sufficient, or if a detailed message should be logged as well.
Write clean-up code
Identify, and then implement, the steps to be followed in order to restore the environment to the original state for each test. The goal is to ensure that there are no side effects from running the tests.
Test the test

Verify that each developer test works correctly. To do this:

  • Run the test(s), observe their behavior, and fix any defects in the tests.
  • Ensure that the expected results are defined properly and that they're being checked correctly.
  • Check the clean-up logic for each test.
  • Ensure that each developer test works within your test suite framework.
Key Considerations
  1. Automate tests via a unit regression testing tool (for example, xUnit) so that tests may be run by developers whenever they make changes to the code.
  2. Test to the risk of the component. For example, the more critical a component is, the more important it is to test it thoroughly.
  3. Pair with the Tester in all steps of this task to gain insight on testing and quality considerations.
Alternatives
Rely on acceptance tests to validate your software. This will likely be time consuming, late, and not as effective as developer testing in identifying bugs and finding their location in the code.
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