Add has_sequence() variant with schema and no description

[Su-Shee]

I use "has_sequence" to test a column with type serial.

The test fails when I omit the description part and returns ok if I add one.

It does NOT however return "If you omit the test description, it will be set to "Sequence :sequence should exist"." as the documentation says.

On PostgreSQL 9.1.3 on i486-slackware-linux-gnu, compiled by gcc (GCC) 4.7.0, 32-bit, tested with pgtap 0.93.0 and 0.94.0

[theory]

I usually test a SERIAL column like this:

SELECT has_column(        'foos', 'foo_id' );
SELECT col_type_is(       'foos', 'foo_id', 'integer' );
SELECT col_not_null(      'foos', 'foo_id' );
SELECT col_has_default(   'foos', 'foo_id' );
SELECT col_default_is(    'foos', 'foo_id', 'nextval(''foos_foo_id_seq''::regclass)' );
SELECT col_is_pk(         'foos', 'foo_id' );

You can test for the sequence like this:

SELECT has_sequence('foos_foo_id_seq');

If you have it in a schema not in the search path, so you have to pass the schema name, yeah, you have to specify the description. That's a bug. :-( I usually set the search path, myself, so that I don't worry about the schema arg.

[theory]

Oh, there is no form of has_sequence() that includes the schema and not the description. From the docs:

SELECT has_sequence( :schema, :sequence, :description );
SELECT has_sequence( :sequence, :description );
SELECT has_sequence( :sequence );

There are a few functions like that, I think because, earlier in the development of pgTAP, I avoided having functions with the same number of params, because otherwise Postgres could complain that two functions matched the signature, if we also had this:

SELECT has_sequence( :schema, :sequence );

However, I later just started disambiguating by casting that second argument to NAME. But it's kind of a PITA. Anyway, that signature could be added, but it might break existing tests in the wild that pass :sequence and :description without any casts.