Re: Making background psql nicer to use in tap tests

On 2023-03-17 Fr 10:08, Daniel Gustafsson wrote:
>
>> A common perl idiom is to start private routine names with an underscore. so I'd rename wait_connect to _wait_connect;
> There are quite a few routines documented as internal in Cluster.pm which don't
> start with an underscore.  Should we change them as well?  I'm happy to prepare
> a separate patch to address that if we want that.


Possibly. There are two concerns. First, make sure that they really are 
private. Last time I looked I think I noticed at least one thing that 
was alleged to be private but was called from a TAP script. Second, 
unless we backpatch it there will be some drift between branches, which 
can make backpatching things a bit harder. But by all means prep a patch 
so we can see the scope of the issue.


>
>> Why is $restart_before_query a package/class level value instead of an instance value? And why can we only ever set it to 1 but not back again? Maybe we don't want to, but it looks odd.
> It was mostly a POC to show what I meant with the functionality.  I think there
> should be a way to turn it off (set it to zero) even though I doubt it will be
> used much.


A common idiom is to have a composite getter/setter method for object 
properties something like this


    sub settingname

    {

       my ($self, $arg) = @_;

       $self->{settingname} = $arg if defined $arg;

       return $self->{settingname};

    }


>
>> If we are going to keep this as a separate package, then we should put some code in the constructor to prevent it being called from elsewhere than the Cluster package. e.g.
>>
>>      # this constructor should only be called from PostgreSQL::Test::Cluster
>>      my ($package, $file, $line) = caller;
>>      
>>      die "Forbidden caller of constructor: package: $package, file: $file:$line"
>>        unless $package eq 'PostgreSQL::Test::Cluster';
> I don't have strong feelings about where to place this, but Cluster.pm is
> already quite long so I see a small upside to keeping it separate to not make
> that worse.
>

Yeah, I can go along with that.


cheers


andrew

--
Andrew Dunstan
EDB:https://www.enterprisedb.com