[dmd 2.090.1 linux 64-bit]

The following code does not report the correct unit test summary.
The report says 1 unit test passed.

~~~~~
shared static this() {
    import core.exception;
    assertHandler(&cah);
}

void
cah(string file, ulong line, string msg) nothrow {
    import core.stdc.stdio: printf;
    printf("==============================\n");
    printf("Assert error: %s %d: %s\n", file.ptr, line, msg.ptr);
    printf("==============================\n");
}

unittest {
    assert(false);
}
~~~~~

On Monday, 24 February 2020 at 00:50:38 UTC, ric maicle wrote:
> [dmd 2.090.1 linux 64-bit]
>
> The following code does not report the correct unit test summary.
> The report says 1 unit test passed.
>
> ~~~~~
> shared static this() {
>     import core.exception;
>     assertHandler(&cah);
> }
>
> void
> cah(string file, ulong line, string msg) nothrow {
>     import core.stdc.stdio: printf;
>     printf("==============================\n");
>     printf("Assert error: %s %d: %s\n", file.ptr, line, msg.ptr);
>     printf("==============================\n");
> }
>
> unittest {
>     assert(false);
> }
> ~~~~~

Looks like you have to throw an Error at the end of your custom handler, e.g:

---
void
cah(string file, ulong line, string msg) nothrow {
    import core.stdc.stdio: printf;
    import core.exception : AssertError;
    printf("==============================\n");
    printf("Assert error: %s %d: %s\n", file.ptr, line, msg.ptr);
    printf("==============================\n");
    throw new AssertError("");
}
---

For a betterC program you can use an HLT:

---
void
cah(string file, ulong line, string msg) nothrow {
    import core.stdc.stdio: printf, fflush, stdout;
    printf("==============================\n");
    printf("Assert error: %s %d: %s\n", file.ptr, line, msg.ptr);
    printf("==============================\n");
    fflush(stdout);
    asm nothrow { hlt; }
}
---