builttotest

Builttotest is a software development concept that emphasizes constructing software with testability in mind from the outset. The idea is to design components, interfaces, and systems so that automated tests can be written effectively and executed reliably throughout the development lifecycle. Proponents view testability as a measurable quality attribute that guides architecture, coding practices, and tool choices.

Key practices associated with builttotest include modularity, explicit dependencies, small cohesive units, and separation of concerns, along with observable and controllable behavior to enable reliable testing. Common techniques involve dependency injection, interface-based design, and the use of mocks, fakes, and stubs to isolate units for testing. The approach often aligns with test-driven development (TDD) and behavior-driven development (BDD), where tests influence design decisions and code structure.

In practice, teams apply builttotest through unit tests, integration tests, and automated end-to-end tests integrated into continuous integration pipelines. The approach supports refactoring by maintaining a test suite that protects behavior and helps ensure that changes do not introduce regressions. Benefits include faster feedback, easier maintenance, safer refactoring, and clearer interfaces. Potential drawbacks include initial development overhead and the risk of overly brittle tests or misapplied focus on tests at the expense of other concerns. Applying the approach to legacy code can require substantial changes or incremental adoption.

Builttotest is discussed in software engineering discourse as a design and testing philosophy rather than a single standardized methodology. It intersects with concepts such as test-driven development, design for testability, and dependency management, and it is commonly supported by continuous integration and modern testing frameworks.