# Testing

The default test suite is deterministic and has no elapsed-time assertions.
Configure a build, compile it, and run the tests with CTest:

```sh
cmake -S . -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build
ctest --test-dir build --output-on-failure
```

The tests independently check board dimensions, square multiplicities, bounds,
overlap, and complete coverage.  They cover small unsatisfiable solver inputs, a
known order-8 solution, invalid placement diagnostics, and construction of an
order-9 solution from the order-8 fixture.  The routed order-9 solver test
checks that its search counters exactly match order 8.  The skyline tests check
smallest-width valley selection and deterministic tie-breaking, validate an
order-8 result with descending candidates, and independently validate a direct
order-9 search with ascending candidates.  That direct test is deliberately
separate from the public order-9 route, which uses even-predecessor
construction.  The rendering test also formats the known order-8 solution and
checks the resulting grid dimensions and coverage.

When Python is available, `reference-support` also tests the dependency-free
placement JSON validator.  If the optional OR-Tools package is present, it
additionally builds and solves the trivial order-1 CP-SAT model; otherwise that
part is skipped without changing the default test result.

## Debug and sanitizers

Use a separate build directory for each configuration:

```sh
cmake -S . -B build-debug -DCMAKE_BUILD_TYPE=Debug
cmake --build build-debug
ctest --test-dir build-debug --output-on-failure

cmake -S . -B build-asan -DCMAKE_BUILD_TYPE=RelWithDebInfo \
  -DCMAKE_CXX_FLAGS="-fsanitize=address -fno-omit-frame-pointer" \
  -DCMAKE_EXE_LINKER_FLAGS="-fsanitize=address"
cmake --build build-asan
ctest --test-dir build-asan --output-on-failure

cmake -S . -B build-ubsan -DCMAKE_BUILD_TYPE=RelWithDebInfo \
  -DCMAKE_CXX_FLAGS="-fsanitize=undefined -fno-omit-frame-pointer" \
  -DCMAKE_EXE_LINKER_FLAGS="-fsanitize=undefined"
cmake --build build-ubsan
ctest --test-dir build-ubsan --output-on-failure
```

The sanitizer flags shown are supported by Clang and GCC.  Other compilers may
require different flags.