catchorg/catch2

Catch2 is a testing framework for C++ that makes it straightforward to write automated tests for your code. A testing framework is a tool that lets you describe what you expect your program to do, then automatically checks whether it actually does that whenever you run the tests, catching regressions before they reach users. What sets Catch2 apart from older C++ testing tools is how natural it is to write tests with it. Test names can be plain English sentences rather than valid code identifiers, and assertions read like ordinary boolean expressions rather than cryptic macro calls. The README shows a concise example: a function that computes factorials is tested by calling it with known inputs and checking the results with simple REQUIRE statements, all inside a TEST_CASE block labelled "Factorials are computed." That minimal amount of ceremony is by design. Beyond unit tests, Catch2 also includes a basic micro-benchmarking feature (for measuring how fast a piece of code runs) and support for BDD-style test organization (Behaviour-Driven Development, a style where tests are written to describe behavior in terms a non-programmer can read). Benchmarks are kept separate from regular tests and only run when explicitly requested. Catch2 v3 changed from a single-file library (where you dropped one header into your project) to a conventional multi-file library that you install and link against. It requires a C++ compiler supporting C++14 or later. You would reach for Catch2 when building any C++ project where you want a low-friction, readable testing setup without pulling in a heavyweight framework.