Re: [Qemu-devel] [PATCH] qdev-monitor-test: simplify using g_assert_cmpstr()

[Markus Armbruster <armbru@redhat.com>]

Stefan Hajnoczi <stefanha@redhat.com> writes:

> Use g_assert_cmpstr() instead of combining g_assert() and strcmp(3).
> This simplifies the code since we no longer have to play games to
> distinguish NULL from "" using "(null)".
>
> gcc extension haters will also be happy that ?: was dropped.
>
> Suggested-by: Markus Armbruster <armbru@redhat.com>
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
>  tests/qdev-monitor-test.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/tests/qdev-monitor-test.c b/tests/qdev-monitor-test.c
> index ba7f9cc..eefaab8 100644
> --- a/tests/qdev-monitor-test.c
> +++ b/tests/qdev-monitor-test.c
> @@ -32,8 +32,9 @@ static void test_device_add(void)
>                     "}}");
>      g_assert(response);
>      error = qdict_get_qdict(response, "error");
> -    g_assert(!strcmp(qdict_get_try_str(error, "desc") ?: "",
> -                     "Device needs media, but drive is empty"));
> +    g_assert_cmpstr(qdict_get_try_str(error, "desc"),
> +                    ==,
> +                    "Device needs media, but drive is empty");
>      QDECREF(response);
>  
>      /* Delete the drive */

Outside this patch's scope, but here goes anyway: why do we test the
value of member desc?  Isn't that awfully fragile?

It broke once already, in Andreas's commit 75884af "virtio-blk: Convert
to QOM realize".  Andreas, do you remember why you tossed the class ==
GenericError check instead of the desc check?

> @@ -42,7 +43,7 @@ static void test_device_add(void)
>                     "   \"command-line\": \"drive_del drive0\""
>                     "}}");
>      g_assert(response);
> -    g_assert(!strcmp(qdict_get_try_str(response, "return") ?: "(null)", ""));
> +    g_assert_cmpstr(qdict_get_try_str(response, "return"), ==, "");
>      QDECREF(response);
>  
>      /* Try to re-add the drive.  This fails with duplicate IDs if a leaked
> @@ -53,8 +54,7 @@ static void test_device_add(void)
>                     "   \"command-line\": \"drive_add pci-addr=auto if=none,id=drive0\""
>                     "}}");
>      g_assert(response);
> -    g_assert(!strcmp(qdict_get_try_str(response, "return") ?: "",
> -                     "OK\r\n"));
> +    g_assert_cmpstr(qdict_get_try_str(response, "return"), ==, "OK\r\n");
>      QDECREF(response);
>  
>      qtest_end();

Reviewed-by: Markus Armbruster <armbru@redhat.com>