In our current testing environment, we spend a significant amount of effort crafting end-to-end tests for error conditions that could easily be captured by unit tests (or we simply forgo some hard-to-setup and rare error conditions). Unit tests additionally provide stability to the codebase and can simplify debugging through isolation. Turning parts of Git into libraries[1] gives us the ability to run unit tests on the libraries and to write unit tests in C. Writing unit tests in pure C, rather than with our current shell/test-tool helper setup, simplifies test setup, simplifies passing data around (no shell-isms required), and reduces testing runtime by not spawning a separate process for every test invocation. This series begins with a project document covering our goals for adding unit tests and a discussion of alternative frameworks considered, as well as the features used to evaluate them. A rendered preview of this doc can be found at [2]. It also adds Phillip Wood's TAP implemenation (with some slightly re-worked Makefile rules) and a sample strbuf unit test. Finally, we modify the configs for GitHub and Cirrus CI to run the unit tests. Sample runs showing successful CI runs can be found at [3], [4], and [5]. [1] https://lore.kernel.org/git/CAJoAoZ=Cig_kLocxKGax31sU7Xe4==BGzC__Bg2_pr7krNq6MA@xxxxxxxxxxxxxx/ [2] https://github.com/steadmon/git/blob/unit-tests-asciidoc/Documentation/technical/unit-tests.adoc [3] https://github.com/steadmon/git/actions/runs/5884659246/job/15959781385#step:4:1803 [4] https://github.com/steadmon/git/actions/runs/5884659246/job/15959938401#step:5:186 [5] https://cirrus-ci.com/task/6126304366428160 (unrelated tests failed, but note that t-strbuf ran successfully) Changes in v10: - Included a promised style cleanup in test-lib.c that was accidentally dropped in v9. Changes in v9: - Included some asciidoc cleanups suggested by Oswald Buddenhagen. - Applied a style fixup that Coccinelle complained about. - Applied some NULL-safety fixups. - Used check_*() more widely in t-strbuf helper functions Changes in v8: - Flipped return values for TEST, TEST_TODO, and check_* macros & functions. This makes it easier to reason about control flow for patterns like: if (check(some_condition)) { ... } - Moved unit test binaries to t/unit-tests/bin to simplify .gitignore patterns. - Removed testing of some strbuf implementation details in t-strbuf.c Changes in v7: - Fix corrupt diff in patch #2, sorry for the noise. Changes in v6: - Officially recommend using Phillip Wood's TAP framework - Add an example strbuf unit test using the TAP framework as well as Makefile integration - Run unit tests in CI Changes in v5: - Add comparison point "License". - Discuss feature priorities - Drop frameworks: - Incompatible licenses: libtap, cmocka - Missing source: MyTAP - No TAP support: µnit, cmockery, cmockery2, Unity, minunit, CUnit - Drop comparison point "Coverage reports": this can generally be handled by tools such as `gcov` regardless of the framework used. - Drop comparison point "Inline tests": there didn't seem to be strong interest from reviewers for this feature. - Drop comparison point "Scheduling / re-running": this was not supported by any of the main contenders, and is generally better handled by the harness rather than framework. - Drop comparison point "Lazy test planning": this was supported by all frameworks that provide TAP output. Changes in v4: - Add link anchors for the framework comparison dimensions - Explain "Partial" results for each dimension - Use consistent dimension names in the section headers and comparison tables - Add "Project KLOC", "Adoption", and "Inline tests" dimensions - Fill in a few of the missing entries in the comparison table Changes in v3: - Expand the doc with discussion of desired features and a WIP comparison. - Drop all implementation patches until a framework is selected. - Link to v2: https://lore.kernel.org/r/20230517-unit-tests-v2-v2-0-21b5b60f4b32@xxxxxxxxxx Josh Steadmon (2): unit tests: Add a project plan document ci: run unit tests in CI Phillip Wood (1): unit tests: add TAP unit test framework .cirrus.yml | 2 +- Documentation/Makefile | 1 + Documentation/technical/unit-tests.txt | 240 ++++++++++++++++++ Makefile | 28 ++- ci/run-build-and-tests.sh | 2 + ci/run-test-slice.sh | 5 + t/Makefile | 15 +- t/t0080-unit-test-output.sh | 58 +++++ t/unit-tests/.gitignore | 1 + t/unit-tests/t-basic.c | 95 +++++++ t/unit-tests/t-strbuf.c | 120 +++++++++ t/unit-tests/test-lib.c | 330 +++++++++++++++++++++++++ t/unit-tests/test-lib.h | 149 +++++++++++ 13 files changed, 1041 insertions(+), 5 deletions(-) create mode 100644 Documentation/technical/unit-tests.txt create mode 100755 t/t0080-unit-test-output.sh create mode 100644 t/unit-tests/.gitignore create mode 100644 t/unit-tests/t-basic.c create mode 100644 t/unit-tests/t-strbuf.c create mode 100644 t/unit-tests/test-lib.c create mode 100644 t/unit-tests/test-lib.h Range-diff against v9: -: ---------- > 1: f706ba9b68 unit tests: Add a project plan document 1: 8b831f4937 ! 2: 7a5e21bcff unit tests: add TAP unit test framework @@ t/unit-tests/test-lib.c (new) + if (ctx.result == RESULT_SKIP) { + test_msg("skipping check '%s' at %s", check, location); + return 1; -+ } else if (!ctx.todo) { ++ } ++ if (!ctx.todo) { + if (ok) { + test_pass(); + } else { 2: 08d27bb5f9 = 3: 0129ec062c ci: run unit tests in CI base-commit: a9e066fa63149291a55f383cfa113d8bdbdaa6b3 -- 2.42.0.869.gea05f2083d-goog
