Writing new unit tests with PostgresNode

I've been taking a look at the Perl test infrastructure ( src/test/perl ) for writing multi-node tests, starting with PostgresNode.pm and I have a few comments based on my first approach to the code "cold".

I think a README in src/test/perl/ would be very helpful. It's currently not at all clear how to go about using the new test infrastructure when first looking at it, particularly adding new test suites. Also a summary of available test facilities and some short examples or pointers to where they can be found ( src/bin/, src/test/ssl, etc).

The docs at http://www.postgresql.org/docs/devel/static/regress-tap.html mention the use of tap for client programs but don't have anything on writing/using the framework. It doesn't seem to be very close to / compatible with http://pgtap.org/ unless I'm missing something obvious.

I want to add tests for failover slots but I'm not sure where to put them or how to set up the test skeleton. So I went looking, and I could use confirmation that the below is roughly right so I can write it up for some quickstart docs.

It *looks* like one needs to create a Makefile with:

clean:

        rm -rf ./tmp_check

Then create a subdir src/test/mytests/t and in it put files named 001_sometest.pl etc. Each of which should import PostgresNode and generally then create new instances indirectly via the PostgresNode::get_new_node function rather than by using the constructor. Then init and start the server and run tests. Like:

use strict;

use warnings;

use PostgresNode;

use TestLib;

diag 'Setting up node';

$node->teardown_node;

Knowledge of perl's Test::More is required since most of the suite is built on it.

The suite should be added to src/test/Makefile's ALWAYS_SUBDIRS entry.

Sound about right? I can tidy that up a bit and turn it into a README and add a reference to that to the public tap docs to tell users where to go if they want to write more tests.

I don't know how many suites we'll want - whether it'll be desirable to have a few suites with lots of tests or to have lots of suites with just a few tests. I'm planning on starting by adding a suite named 'replication' and putting some tests for failover slots in there. Reasonable?

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