[PATCH 4/4] lib: tests: Add sbi_console test

[Andrew Jones <ajones@ventanamicro.com>]

On Thu, Feb 15, 2024 at 02:44:15PM +0000, Ivan Orlov wrote:
> On 2/12/24 18:24, Andrew Jones wrote:
> > On Thu, Feb 08, 2024 at 09:50:50AM +0000, Ivan Orlov wrote:
...
> > > +static void clear_buf(void)
> > > +{
> > > +	pos = 0;
> > > +	sbi_memset(buf, 0, BUF_LEN);
> > 
> > I guess buf[0] = '\0' should be sufficient.
> > 
> 
> Sorry for the late reply, I agree on all of the points you mentioned except
> this one. The 'puts' test stops me from clearing the buffer by setting the
> first char to zero:
> 
> ```
> PUTS_TEST(test, "Hello,", "Hello,\0OpenSBI!");
> ```
> 
> This test checks if 'puts' stops printing after facing \0. 'puts' won't
> print out the \0 to the buffer after printing "Hello,", so in case of the
> 'lazy' buffer clearing there might be other characters in buffer after
> 'Hello,'. In this case, the 'sbi_strcmp' won't stop comparing the strings
> causing the test to fail (despite the behavior is correct).
> 
> I reckon that clearing the buffer completely will help avoiding such tricky
> issues by making the experiment as pure as possible :)

Since the mock console device is a ring buffer it doesn't guarantee zeros
will follow the printed strings. I suggest writing tests which only
confirm the characters printed are in the stream and in the right order,
but not check for anything console device implementation specific.

Thanks,
drew