From: steadmon@google.com
To: git@vger.kernel.org
Cc: Josh Steadmon <steadmon@google.com>,
calvinwan@gmail.com, szeder.dev@gmail.com,
phillip.wood123@gmail.com, chooglen@google.com, avarab@gmail.com,
gitster@pobox.com, sandals@crustytoothpaste.net
Subject: [PATCH RFC v2 2/4] unit tests: Add a project plan document
Date: Wed, 17 May 2023 16:56:32 -0700 [thread overview]
Message-ID: <20230517-unit-tests-v2-v2-2-21b5b60f4b32@google.com> (raw)
In-Reply-To: <20230517-unit-tests-v2-v2-0-21b5b60f4b32@google.com>
Describe what we hope to accomplish by implementing unit tests, and
explain some open questions and milestones.
Change-Id: I182cdc1c15bdd1cbef6ffcf3d216b386f951e9fc
---
Documentation/Makefile | 1 +
Documentation/technical/unit-tests.txt | 47 ++++++++++++++++++++++++++++++++++
2 files changed, 48 insertions(+)
diff --git a/Documentation/Makefile b/Documentation/Makefile
index b629176d7d..3f2383a12c 100644
--- a/Documentation/Makefile
+++ b/Documentation/Makefile
@@ -122,6 +122,7 @@ TECH_DOCS += technical/scalar
TECH_DOCS += technical/send-pack-pipeline
TECH_DOCS += technical/shallow
TECH_DOCS += technical/trivial-merge
+TECH_DOCS += technical/unit-tests
SP_ARTICLES += $(TECH_DOCS)
SP_ARTICLES += technical/api-index
diff --git a/Documentation/technical/unit-tests.txt b/Documentation/technical/unit-tests.txt
new file mode 100644
index 0000000000..7c575e6ef7
--- /dev/null
+++ b/Documentation/technical/unit-tests.txt
@@ -0,0 +1,47 @@
+= Unit Testing
+
+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. 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.
+
+Unit testing in C requires a separate testing harness that we ideally would
+like to be TAP-style and to come with a non-restrictive license. Fortunately,
+there already exists a https://github.com/rra/c-tap-harness/[C TAP harness
+library] with an MIT license (at least for the files needed for our purposes).
+We might also consider implementing
+https://lore.kernel.org/git/c902a166-98ce-afba-93f2-ea6027557176@gmail.com/[our
+own TAP harness] just for Git.
+
+We believe that a large body of unit tests, living alongside the existing test
+suite, will improve code quality for the Git project.
+
+== Open questions
+
+=== TAP harness
+
+We'll need to decide on a TAP harness. The C TAP library is easy to integrate,
+but has a few drawbacks:
+* (copy objections from lore thread)
+* We may need to carry local patches against C TAP. We'll need to decide how to
+ manage these. We could vendor the code in and modify them directly, or use a
+ submodule (but then we'll need to decide on where to host the submodule with
+ our patches on top).
+
+Phillip Wood has also proposed a new implementation of a TAP harness (linked
+above). While it hasn't been thoroughly reviewed yet, it looks to support a few
+nice features that C TAP does not, e.g. lazy test plans and skippable tests.
+
+== Milestones
+
+* Settle on final TAP harness
+* Add useful tests of library-ish code
+* Integrate with CI
+* Integrate with
+ https://lore.kernel.org/git/20230502211454.1673000-1-calvinwan@google.com/[stdlib
+ work]
+* Run along with regular `make test` target
--
2.40.1.606.ga4b1b128d6-goog
next prev parent reply other threads:[~2023-05-17 23:56 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-17 23:56 [PATCH RFC v2 0/4] Add an external testing library for unit tests steadmon
2023-05-17 23:56 ` [PATCH RFC v2 1/4] common-main: split common_exit() into a new file steadmon
2023-05-18 17:17 ` Junio C Hamano
2023-07-14 23:38 ` Splitting common-main (Was: Re: [PATCH RFC v2 1/4] common-main: split common_exit() into a new file) Josh Steadmon
2023-07-15 0:34 ` Splitting common-main Junio C Hamano
2023-08-14 13:09 ` Splitting common-main (Was: Re: [PATCH RFC v2 1/4] common-main: split common_exit() into a new file) Jeff Hostetler
2023-05-17 23:56 ` steadmon [this message]
2023-05-18 13:13 ` [PATCH RFC v2 2/4] unit tests: Add a project plan document Phillip Wood
2023-05-18 20:15 ` Glen Choo
2023-05-24 17:40 ` Josh Steadmon
2023-06-01 9:19 ` Phillip Wood
2023-05-17 23:56 ` [PATCH RFC v2 3/4] Add C TAP harness steadmon
2023-05-18 13:15 ` Phillip Wood
2023-05-18 20:50 ` Josh Steadmon
2023-05-17 23:56 ` [PATCH RFC v2 4/4] unit test: add basic example and build rules steadmon
2023-05-18 13:32 ` Phillip Wood
2023-06-09 23:25 ` [RFC PATCH v3 0/1] Add a project document for adding unit tests Josh Steadmon
2023-06-09 23:25 ` [RFC PATCH v3 1/1] unit tests: Add a project plan document Josh Steadmon
2023-06-13 22:30 ` Junio C Hamano
2023-06-30 22:18 ` Josh Steadmon
2023-06-29 19:42 ` Linus Arver
2023-06-29 20:48 ` Josh Steadmon
2023-06-30 19:31 ` Linus Arver
2023-07-06 18:24 ` Glen Choo
2023-07-06 19:02 ` Junio C Hamano
2023-07-06 22:48 ` Glen Choo
2023-06-30 21:33 ` Josh Steadmon
2023-06-29 21:21 ` Junio C Hamano
2023-06-30 0:11 ` Linus Arver
2023-06-30 14:07 ` Phillip Wood
2023-06-30 18:47 ` K Wan
2023-06-30 22:35 ` Josh Steadmon
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