Re: meson missing test dependencies

Hi,

On 2024-12-02 11:10:56 +0100, Peter Eisentraut wrote:
> I have noticed that under meson many tests don't have dependencies on the
> build artifacts that they are testing. As an example among many, if you
> make a source code change in contrib/cube/cube.c (see patch 0001 for a demo)
> and then run
>
> make -C contrib/cube check
>
> the test run will reflect the changed code, because the "check" targets
> typically depend on the "all" targets. But if you do this under meson with
>
> meson test -C build --suite setup --suite cube
>
> the code will not be rebuilt first, and the test run will not reflect the
> changed code.

That's unfortunately a very partial fix - because we insist on tests being run
against a temporary install, we don't just need to rebuild the code, we also
need to re-install it. Without that you don't, e.g., see server changes.

Currently the install is done as part of the setup/tmp_install test.

It'd be *much* nicer to create the temporary installation as a build step, but
unfortunately meson currently builds all test dependencies when you build the
default target. Which unfortunately would mean that we'd reinstall the temp
installation whenever 'ninja' is issued. Hence the weird setup with the test
doing the install. There's recent progress towards improving this in meson,
luckily.

However, it looks like the tmp_install test *does* miss dependencies too and I
see no reason to not fix that.

Medium term I think we should work on being able to run our tests from the
source tree. That'd substantially improve the time to run individual tests, I
think.

Greetings,

Andres Freund

diff --git i/meson.build w/meson.build
index ff3848b1d85..55b751a0c6b 100644
--- i/meson.build
+++ w/meson.build
@@ -3263,6 +3263,7 @@ test('tmp_install',
priority: setup_tests_priority,
timeout: 300,
is_parallel: false,
+ depends: all_built,
suite: ['setup'])

test('install_test_files',