curl/tests/unit
Viktor Szakats 39542f0993
cmake: add native clang-tidy support for tests, with concatenated sources
Tests are build in "unity"-style, by including sources into an umbrella
C files (similar to how CMake unity works). This does not play well with
clang-tidy, which seems to unconditionally ignore C sources included
like this. To fix it, curl's CMake implements a manual clang-tidy
support for tests, which  compiles sources one-by-one, while also making
sure sources compile cleanly standalone (e.g. all sources need to
include `first.h`). The manual clang-tidy implementation is fragile, and
performance, in particular when targeting Windows, is abysmal.

This patch introduces an alternate solution, enabled by the
`_CURL_TESTS_CONCAT=ON` option. In this mode, umbrella sources include
the actual sources instead of `#including` them. Allowing to use CMake's
built-in clang-tidy support to compile them, with clang-tidy actually
checking the sources. Making the manual clang-tidy support unnecessary.
In the Windows CI job it results in a 4x performance improvement (4m ->
1m), making it practical to run clang-tidy on tests on Windows, in CI.

The main downside is that clang-tidy doesn't understand the `#line`
directive. Meaning issues found show the wrong filename and line number
next to them. It's not impossible to locate errors this way, but also
not convenient.

Minor/potential downside is that the concatenated source needs to be
reassembled each time an original source is updated. This may result in
more copying on the disk when used in local development. The largest
source is 1.4MB, so probably not a show-stopper on most machines.

Another is the complexity of maintaining two methods in parallel, which
may be necessary till clang-tidy understands `#line`:
https://github.com/llvm/llvm-project/issues/62405

This solution may in theory also enable adding clang-tidy support for
tests in autotools, though I haven't tried.

Targeted for curl CI for now, and used in a GHA/windows job. 100%
experimental, not recommended outside these.

Closes #20667
2026-02-25 17:28:35 +01:00
..
.gitignore tests: always make bundles, adapt build and tests 2025-06-14 21:08:23 +02:00
CMakeLists.txt cmake: add native clang-tidy support for tests, with concatenated sources 2026-02-25 17:28:35 +01:00
Makefile.am build: merge TrackMemory (CURLDEBUG) into debug-enabled option 2026-01-19 18:43:17 +01:00
Makefile.inc progress: narrower time display, multiple fixes 2026-01-04 14:42:08 +01:00
README.md badwords: fix issues found in tests 2025-11-17 13:30:35 +01:00
unit1300.c tidy-up: one more round of formatting nits 2025-12-04 19:30:59 +01:00
unit1302.c build: use more const 2026-02-02 12:32:49 +01:00
unit1303.c timeout handling: auto-detect effective timeout 2026-01-20 16:43:45 +01:00
unit1304.c test1304: drop CURL_UNCONST() 2026-02-02 12:28:13 +01:00
unit1305.c tests: rename more CURLcode variables to result 2026-01-26 05:46:48 +01:00
unit1307.c tests: include headers only when used 2025-12-31 17:00:56 +01:00
unit1309.c clang-tidy: enable readability-math-missing-parentheses, adjust code 2026-02-23 18:57:40 +01:00
unit1323.c tidy-up: one more round of formatting nits 2025-12-04 19:30:59 +01:00
unit1330.c build: stop overriding standard memory allocation functions 2025-11-28 10:44:26 +01:00
unit1395.c tidy-up: one more round of formatting nits 2025-12-04 19:30:59 +01:00
unit1396.c tests: rename CURLMcode variables to mresult 2025-12-17 08:55:12 +01:00
unit1397.c tidy-up: miscellaneous 2025-12-12 04:18:48 +01:00
unit1398.c tidy-up: miscellaneous 2026-02-12 14:52:16 +01:00
unit1399.c time-keeping: keep timestamp in multi, always update 2025-12-18 22:10:06 +01:00
unit1600.c build: use more const 2026-02-02 12:32:49 +01:00
unit1601.c build: use more const 2026-02-02 12:32:49 +01:00
unit1602.c build: stop overriding standard memory allocation functions 2025-11-28 10:44:26 +01:00
unit1603.c build: use more const 2026-02-02 12:32:49 +01:00
unit1605.c tests: rename CURLMcode variables to mresult 2025-12-17 08:55:12 +01:00
unit1606.c tests: rename CURLMcode variables to mresult 2025-12-17 08:55:12 +01:00
unit1607.c build: drop unused includes 2025-12-19 02:04:20 +01:00
unit1608.c tests: rename more CURLcode variables to result 2026-01-26 05:46:48 +01:00
unit1609.c tidy-up: miscellaneous 2026-01-15 13:06:13 +01:00
unit1610.c build: use more const 2026-02-02 12:32:49 +01:00
unit1611.c build: use more const 2026-02-02 12:32:49 +01:00
unit1612.c build: use more const 2026-02-02 12:32:49 +01:00
unit1614.c tidy-up: one more round of formatting nits 2025-12-04 19:30:59 +01:00
unit1615.c build: use more const 2026-02-02 12:32:49 +01:00
unit1616.c tests: fix to use uint32_t where necessary 2026-01-07 17:01:06 +01:00
unit1620.c tests: rename more CURLcode variables to result 2026-01-26 05:46:48 +01:00
unit1636.c progress: narrower time display, multiple fixes 2026-01-04 14:42:08 +01:00
unit1650.c build: use more const 2026-02-02 12:32:49 +01:00
unit1651.c tests: rename more CURLcode variables to result 2026-01-26 05:46:48 +01:00
unit1652.c build: constify memchr()/strchr()/etc result variables 2026-01-25 12:21:54 +01:00
unit1653.c build: use more const 2026-02-02 12:32:49 +01:00
unit1654.c unit1654: fix clang-tidy bugprone-redundant-branch-condition 2026-02-20 17:33:35 +01:00
unit1655.c tests: fix formatting nits 2025-11-28 23:15:35 +01:00
unit1656.c tests: rename more CURLcode variables to result 2026-01-26 05:46:48 +01:00
unit1657.c tests: rename more CURLcode variables to result 2026-01-26 05:46:48 +01:00
unit1658.c build: use more const 2026-02-02 12:32:49 +01:00
unit1660.c tests: rename more CURLcode variables to result 2026-01-26 05:46:48 +01:00
unit1661.c clang-tidy: drop redundant casts 2026-02-19 15:27:17 +01:00
unit1663.c tests: rename more CURLcode variables to result 2026-01-26 05:46:48 +01:00
unit1664.c tidy-up: miscellaneous 2026-02-25 14:44:56 +01:00
unit1979.c http_aws_sigv4: fix query normalization of %2b 2026-02-10 07:52:18 +01:00
unit1980.c http_aws_sigv4: fix query normalization of %2b 2026-02-10 07:52:18 +01:00
unit2600.c tidy-up: miscellaneous 2026-02-25 14:44:56 +01:00
unit2601.c tests: rename more CURLcode variables to result 2026-01-26 05:46:48 +01:00
unit2602.c tests: rename more CURLcode variables to result 2026-01-26 05:46:48 +01:00
unit2603.c clang-tidy: drop redundant casts 2026-02-19 15:27:17 +01:00
unit2604.c tests: rename CURLMcode variables to mresult 2025-12-17 08:55:12 +01:00
unit2605.c tests: rename more CURLcode variables to result 2026-01-26 05:46:48 +01:00
unit3200.c build: use more const 2026-02-02 12:32:49 +01:00
unit3205.c build: use more const 2026-02-02 12:32:49 +01:00
unit3211.c tidy-up: miscellaneous 2026-01-15 13:06:13 +01:00
unit3212.c tests: fix to use uint32_t where necessary 2026-01-07 17:01:06 +01:00
unit3213.c tidy-up: miscellaneous 2026-01-15 13:06:13 +01:00
unit3214.c mimepost: allocate main struct on-demand 2026-01-12 16:21:02 +01:00
unit3216.c ratelimit: download finetune 2026-01-16 16:42:31 +01:00

Unit tests

The goal is to add tests for all functions in libcurl. If functions are too big and complicated, we should split them into smaller and testable ones.

Build Unit Tests

./configure --enable-debug is required for the unit tests to build. To enable unit tests, there is a separate static libcurl built that is used exclusively for linking unit test programs. Just build everything as normal, and then you can run the unit test cases as well.

Run Unit Tests

Unit tests are run as part of the regular test suite. If you have built everything to run unit tests, to can do 'make test' at the root level. Or you can cd tests and make and then invoke individual unit tests with ./runtests.pl NNNN where NNNN is the specific test number.

Debug Unit Tests

If a specific test fails you get told. The test case then has output left in the %LOGDIR subdirectory, but most importantly you can re-run the test again using gdb by doing ./runtests.pl -g NNNN. That is, add a -g to make it start up gdb and run the same case using that.

Write Unit Tests

We put tests that focus on an area or a specific function into a single C source file. The source file should be named unitNNNN.c where NNNN is a previously unused number.

Add your test to tests/unit/Makefile.inc (if it is a unit test). Add your test data filename to tests/data/Makefile.am

You also need a separate file called tests/data/testNNNN (using the same number) that describes your test case. See the test1300 file for inspiration and the tests/FILEFORMAT.md documentation.

For the actual C file, here's a simple example:

    #include "unitcheck.h"

    #include "a libcurl header.h" /* from the lib directory */

    static CURLcode test_unit9998(const char *arg)
    {
      UNITTEST_BEGIN_SIMPLE

      /* here you start doing things and checking that the results are good */

      fail_unless( size == 0 , "initial size should be zero" );
      fail_if( head == NULL , "head should not be initiated to NULL" );

      /* you end the test code like this: */

      UNITTEST_END_SIMPLE
    }

Here's an example using optional initialization and cleanup:

    #include "unitcheck.h"

    #include "a libcurl header.h" /* from the lib directory */

    static CURLcode t9999_setup(void)
    {
      /* whatever you want done first */
      return CURLE_OK;
    }

    static void t9999_stop(void)
    {
      /* done before shutting down and exiting */
    }

    static CURLcode test_unit9999(const char *arg)
    {
      UNITTEST_BEGIN(t9999_setup())

      /* here you start doing things and checking that the results are good */

      fail_unless( size == 0 , "initial size should be zero" );
      fail_if( head == NULL , "head should not be initiated to NULL" );

      /* you end the test code like this: */

      UNITTEST_END(t9999_stop())
    }