fix(pgrx-tests): respect configured PostgreSQL GUCs

[0xPoe]

close #2151

pgrx-tests sets a few session-level logging defaults when creating a client. In this PR, I have baked pgrx's defaults into postgresql.conf. Now they can be overridden by the user's postgresql_conf_options.

I just added a simple unit test instead of an integration test, as there is no existing integration test suite in the pgrx-tests crate.

[0xPoe]

🔢 Self-check (PR reviewed by myself and ready for feedback)

• Code compiles successfully

• Unit tests added

• No AI-generated elegant nonsense in PR.

• Comments added where necessary

• PR title and description updated

• PR size is reasonable

[eeeebbbbrrrr]

Rather than issuing SETs ourselves I think we should bake pgrx's defaults into "postgresql.conf" and allow what an extension specifies in its fn postgresql_conf_options() to override our defaults.

Thoughts? Wanna rework this?

[0xPoe]

Rather than issuing SETs ourselves I think we should bake pgrx's defaults into "postgresql.conf" and allow what an extension specifies in its fn postgresql_conf_options() to override our defaults.

Thoughts? Wanna rework this?

Makes sense. I'll rework this by moving the pgrx logging defaults into the generated Postgres config.

[0xPoe]

I have tested locally:

1. Setup a new pgrx project:

WORK="$(mktemp -d)"
cd "$WORK"

cargo install --git "https://github.com/0xPoe/pgrx.git" --branch "poe-patch-guc" cargo-pgrx --root "$WORK/.tools"

"$WORK/.tools/bin/cargo-pgrx" pgrx new pgrx_issue2151_check
cd pgrx_issue2151_check

2. Update the Cargo.toml to use this PR:

[patch.crates-io]
pgrx = { git = "https://github.com/0xPoe/pgrx.git", branch = "poe-patch-guc" }
pgrx-tests = { git = "https://github.com/0xPoe/pgrx.git", branch = "poe-patch-guc" }

3. Replace src/lib.rs with this full file:

cat > src/lib.rs <<'EOF'
use pgrx::prelude::*;

::pgrx::pg_module_magic!(name, version);

#[pg_extern]
fn hello_pgrx_issue2151_check() -> &'static str {
    "Hello, pgrx_issue2151_check"
}

#[cfg(any(test, feature = "pg_test"))]
#[pg_schema]
mod tests {
    #[pgrx::pg_test]
    fn postgresql_conf_options_controls_log_min_messages() {
        let value = pgrx::Spi::get_one::<String>("SELECT current_setting('log_min_messages');")
            .expect("SPI should succeed")
            .expect("current_setting should return a value");

        assert_eq!(value, "debug1");
    }
}

/// This module is required by `cargo pgrx test` invocations.
/// It must be visible at the root of your extension crate.
#[cfg(test)]
pub mod pg_test {
    pub fn setup(_options: Vec<&str>) {}

    #[must_use]
    pub fn postgresql_conf_options() -> Vec<&'static str> {
        vec!["log_min_messages = debug1"]
    }
}
EOF

5. Run the test:

CARGO_PGRX_TEST_PGDATA="$WORK/pgdata" \
cargo test --no-default-features --features pg18 --lib \
postgresql_conf_options_controls_log_min_messages -- --nocapture

6. Test result:

test tests::pg_postgresql_conf_options_controls_log_min_messages ... ok

[0xPoe]

🔢 Self-check (PR reviewed by myself and ready for feedback)