[PATCH v4 10/10] meson: parse TAP output generated by our tests

From: Patrick Steinhardt <ps@pks.im>
Date: Jun 2, 2025, 06:44 UTC
Message-ID: <20250602-pks-meson-tap-v4-10-052dfde0818a@pks.im>
In-Reply-To: <20250602-pks-meson-tap-v4-0-052dfde0818a@pks.im>

By default, Meson only knows to pay respect to the exit code of tests to judge whether or not it ran successfully. This can be changed though by specifying the "protocol" parameter. Next to the default "exitcode" protocol, Meson also supports the "tap" output that our tests already know to generate.

Unfortunately, the "tap" protocol was incompatible with `meson test --interactive` and caused a hang. We have upstreamed a fix [1] though, so with the recent release of Meson 1.8 that fix is finally out and we can start using the "tap" protocol when running with a recent-enough version of this build tool.

With this change in place, Meson now properly detects how many subtests ran and whether test suites have been skipped:

    ```
    $ meson test t002*
    ninja: Entering directory `/home/pks/Development/git/build'
     1/10 t0024-crlf-archive                  OK              0.17s   2 subtests passed
     2/10 t0022-crlf-rename                   OK              0.18s   2 subtests passed
     3/10 t0029-core-unsetenvvars             SKIP            0.15s
     4/10 t0023-crlf-am                       OK              0.18s   2 subtests passed
     5/10 t0025-crlf-renormalize              OK              0.21s   3 subtests passed
     6/10 t0026-eol-config                    OK              0.25s   5 subtests passed
     7/10 t0020-crlf                          OK              0.81s   36 subtests passed
     8/10 t0028-working-tree-encoding         OK              0.85s   22 subtests passed
     9/10 t0021-conversion                    OK              3.45s   38 subtests passed
    10/10 t0027-auto-crlf                     OK             26.35s   2600 subtests passed

    Ok:                9
    Fail:              0
    Skipped:           1
    ```

Note that when running `meson test --interactive` the test results will now be marked as "ignored". This is because in interactive mode the file descriptors will remain connected to the user's terminal, and it is expected that the user interacts with the tests (e.g., spawn a debugger or use `test_pause`). As such, the TAP output cannot be parsed reliably by Meson in that case, so the tests are marked as ignored accordingly.

[1]: https://github.com/mesonbuild/meson/pull/13980

Signed-off-by: Patrick Steinhardt <ps@pks.im>
---
 meson.build | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/meson.build b/meson.build
index 6fb898a21d1..46c5d068e05 100644
--- a/meson.build
+++ b/meson.build
@@ -2040,6 +2040,14 @@ if get_option('tests')
     'timeout': 0,
   }
 
+  # The TAP protocol was already understood by previous versions of Meson, but
+  # it was incompatible with the `meson test --interactive` flag.
+  if meson.version().version_compare('>=1.8.0')
+    test_kwargs += {
+      'protocol': 'tap',
+    }
+  endif
+
   subdir('t')
 endif

-- 
2.50.0.rc0.629.g846fc57c9e.dirty