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From: Robert Haas <robertmhaas@gmail.com>
Date: Mon, 15 Sep 2025 14:54:25 -0400
Message-ID: 
 <CA+TgmoYZfigfGgKsT2xCg6d8nhS+UFq6zrO6R6Aq+Dqz-=a5UA@mail.gmail.com>
Subject: Re: [PATCH] Add tests for Bitmapset
To: Greg Burd <greg@burd.me>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>,
	Nathan Bossart <nathandbossart@gmail.com>,
 Masahiko Sawada <sawada.mshk@gmail.com>,
	Michael Paquier <michael@paquier.xyz>
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On Mon, Sep 15, 2025 at 2:00=E2=80=AFPM Greg Burd <greg@burd.me> wrote:
> For reference radixtree has:
>
> coverage:      HEAD
>   lines......: 98.3
>   functions..: 97.2
>   branches...: 89.4

+ /* Test negative member in bms_make_singleton */
+ error_caught =3D false;
+ PG_TRY();
+ {
+ bms_make_singleton(-1);
+ }
+ PG_CATCH();
+ {
+ error_caught =3D true;
+ FlushErrorState();
+ }
+ PG_END_TRY();
+ EXPECT_TRUE(error_caught);

This is an anti-pattern for PostgreSQL code. You can't just flush an
error without aborting a transaction or subtransaction to recover.
Even if it could be shown that this were harmless here, I think it's a
terrible idea to have code like this in the tree, as it encourages
people to do exactly the wrong thing.

But backing up a step, this also doesn't really seem like the right
way to test the error conditions. It deliberately throws away the
error message. All this verifies is that you caught an error. If you
let the error escape to the client you could have the expected output
test that you got the expected message.

I think it would be a better idea to structure this as a set of
SQL-callable functions and move a bunch of the logic into SQL.

--=20
Robert Haas
EDB: http://www.enterprisedb.com