Add Unit Test

Add Unit Test

Workflow

1. Inspect the production code and the nearest existing tests before writing a new test.

   • Match the production path under xllm/ to tests/ where possible.
   • Prefer extending an existing nearby *_test.cpp and cc_test target when the behavior belongs to the same domain.
   • Create a new test source only when it improves isolation, keeps platform setup separate, or follows an existing directory pattern.

2. Read the project style guide before editing production files under xllm/, and apply the same C++ style discipline to new test code: .agents/skills/code-review/references/custom-code-style.md.

3. Follow the current test layout and CMake conventions.

   • Read xllm-test-patterns.md when adding a new test file, new cc_test, platform-specific test, or test directory.
   • Use *_test.cpp for C++ test files and *_test.cu for CUDA source tests.
   • Do not create nested test/ or tests/ directories for new unit tests unless the surrounding tree already requires that structure.

4. Wire tests through CMake with include(cc_test) and cc_test(...).

   • Keep source names relative to the current test directory unless an existing target already uses an absolute source path for a production .cpp.
   • Use target names ending in _test.
   • Put platform-directory gates in the parent CMakeLists.txt when the whole child directory is platform-specific.
   • Use target-level if(USE_NPU), if(USE_MLU), if(USE_CUDA), or generator expressions only when a mixed directory contains both generic and platform-specific tests.

5. Write tests for observable behavior, not implementation trivia.

   • Cover success, edge, and error paths touched by the change.
   • Prefer deterministic inputs, fixed seeds, and small tensors/data structures.
   • Keep helpers file-local in an anonymous namespace unless shared by multiple test files.
   • Use TEST/TEST_F names that describe behavior clearly.

6. Validate narrowly before finishing.

   • Always run git diff --check for the changed test paths.
   • Search for stale filenames after moving or renaming tests.
   • Run the narrowest build/test command available locally; if not feasible, state the exact reason and what was checked instead.

Common Commands

rg --files tests/<area>
rg "old_test_name|old_file_name" tests xllm CMakeLists.txt
git diff --check -- tests/<area>

For full remote validation on the development machine, use the repository AGENTS instructions for SSH, container, build, and test commands.