Functional testing
Functional testing evaluates whether software performs specified functions and produces required behavior for given inputs and conditions.
Practices of the Python Pro
A functional test evaluates software behavior by supplying input, determining expected output, obtaining actual output, and comparing the results.
- How it is used
- Verifies that software behaves correctly before performance work and supports confidence during refactoring.
- How deep it goes
- Defines four test steps, demonstrates Python implementation, and compares unit, integration, manual, and performance testing without low-level internals.
- Examples
- Uses mean calculation, e-commerce cart behavior, product SKU transformations, shopping-cart assertions, and an over-removal edge case.
- What you can do after
- Apply it via unittest or pytest to write assertions, detect failures, test alternate outcomes, and build confidence incrementally.
Read how Practices of the Python Pro explains functional testing →
Functional Design and Architecture: Examples in Haskell
Testing that evaluates specified functionality or an isolated unit of application logic without invoking real external services.
- How it is used
- Reduces project risk by validating functional requirements and contracts through isolated tests rather than exercising real external services.
- How deep it goes
- Defines scope, isolation, and testing boundaries, but does not provide a detailed execution procedure or implementation walkthrough.
- Examples
- Uses the Labyrinth console game as a domain example and frames subsystems, modules, and functions as possible test targets.
- What you can do after
- Evaluate/understand it by distinguishing isolated functionality tests from integrated tests involving real subsystems and services.
Read how Functional Design and Architecture: Examples in Haskell explains functional testing →
Related concepts
- testkind of · A test is a procedure or check that evaluates behavior using specified inputs or evidence against expected results or criteria.
- performance testingcontrasts with · Performance testing is the evaluation of a system's behavior, such as its responsiveness, throughput, scalability, stability, or resource use, under specified workloads and operating conditions.
- labeluses · A label is a value or annotation associated with an item that identifies its target category, outcome, or reference answer for learning or evaluation.
- Seleniumimplemented by · Selenium is an open-source suite of tools and APIs for automating web browsers and testing web applications.
- generationuses · Generation is the computational production of outputs from supplied inputs or context, often by applying a model to produce predictions or new content.
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