meson unittest

[axricard]

On Tuesday, 7 January 2025 at 17:55:50 UTC, sfp wrote:
> File `meson.build`:
> ```
> project('unittest', 'd')
>
> mainlib = library('mainlib', ['blah.d'])
>
> executable('maintest', ['main.d'], link_with: [mainlib], 
> d_unittest: true)
> ```

Your first version is indeed wrong because the library is not 
compiled at all in unittest version. you can see this with `-v` 
option of `meson compile` :

```
# '-unittest' opt not present
╰─> meson compile -v
...
[2/5] ldc2 -I=libmainlib.so.p -I=. -I=.. -enable-color -wi -g 
-d-debug -relocation-model=pic 
-makedeps=libmainlib.so.p/blah.d.o.deps 
-of=libmainlib.so.p/blah.d.o -c ../blah.d
...
```

-------------

The second sample is pretty fine, unittests are actually 
activated for the library. The strange behavior comes from D 
runtime, not meson : the main is not being runned because by 
default if a unittest is present, the runtime won't run the main 
function.

see : 
https://dlang.org/phobos/core_runtime.html#.runModuleUnitTests

To have both unittests and main running, you'll have to set the 
`--DRT-testmode` option to "run-main". You can do it either when 
running the binary :

``` bash
./testmain --DRT-testmode="run-main"
```

or in the source code :

```
╰─> cat main.d
extern(C) __gshared string[] rt_options = [ "testmode=run-main"];

import blah;

void main() {
   f();
}
```

You can even put it in your lib :
```
╰─> cat blah.d
extern(C) __gshared string[] rt_options = [ "testmode=run-main"];
...
```

-------------

Note: the default 'testmode' was "run-main" in previous runtime 
version (< 2.080 I believe), so you might get different behavior 
with old compilers

Note2: I'm not 100% sure what happens if rt_options is set in 
multiples files with a different value. Someone knows ?