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digitalmars.D.learn - meson unittest

reply sfp <sfp hush.ai> writes:
Anyone have a good way of yanking out all `unittest { ... }` 
blocks from a library compiled using Meson? It would be nice to 
approximate what dub does.

Meson has mentions this trick in its help docs 
(https://mesonbuild.com/D.html#using-embedded-unittests) but it 
isn't particularly useful. I have a library built from some 
source files, some of which contain `unittest` functions, and 
separate executables which link this library in. I might be using 
it the wrong way, but this trick did nothing useful for me...
Jan 05
parent reply axricard <axelrwiko gmail.com> writes:
On Sunday, 5 January 2025 at 23:52:24 UTC, sfp wrote:

 Anyone have a good way of yanking out all `unittest { ... }` 
 blocks from a library compiled using Meson? It would be nice to 
 approximate what dub does.

 Meson has mentions this trick in its help docs 
 (https://mesonbuild.com/D.html#using-embedded-unittests) but it 
 isn't particularly useful. I have a library built from some 
 source files, some of which contain `unittest` functions, and 
 separate executables which link this library in. I might be 
 using it the wrong way, but this trick did nothing useful for 
 me...


What do you mean by 'not particularly useful' ? Unittests are not 
being runned ?

I assume you have something like this in your `lib/meson.build` 
file :

```
mylib_test = executable('mylib_test', <mylib_srcs + fake_main>, 
d_unittest: true)
test('mylib', mylib_test)
```
Jan 07
parent reply sfp <sfp hush.ai> writes:
On Tuesday, 7 January 2025 at 11:46:46 UTC, axricard wrote:

 [...[

 What do you mean by 'not particularly useful' ? Unittests are 
 not being runned ?

 [...]


I dug into this a bit more and figured out what the problem was.

File `blah.d`:
```
void f() {
   import std.stdio;
   writeln("hi");
}

unittest {
   writeln("bye");
}
```

File `main.d`:
```
import blah;

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

File `meson.build`:
```
project('unittest', 'd')

mainlib = library('mainlib', ['blah.d'])

executable('maintest', ['main.d'], link_with: [mainlib], 
d_unittest: true)
```

Run:
```
$ meson setup builddir
$ cd builddir
$ meson compile
$ ./maintest
```

Outputs "hi" only.

Change `meson.build` to:
```
project('unittest', 'd')

mainlib = library('mainlib', ['blah.d'], d_unittest: true)

executable('maintest', ['main.d'], link_with: [mainlib])
```

Tests run, but `maintest` does not. You can add `d_unittest: 
true` to the `executable` invocation or not---doesn't make a 
difference.

Pretty unclear from the Meson docs what the expected behavior 
should be.
Jan 07
parent axricard <axelrwiko gmail.com> writes:
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` :

```

╰─> 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 ?
Jan 08