spg-engine 7.37.21

//! v7.38 (read01 P3.14) — pg_stat_checkpointer / pg_stat_wal shell views.

use spg_engine::{Engine, QueryResult};

fn col_names(e: &mut Engine, sql: &str) -> Vec<String> {
    match e
        .execute(sql)
        .unwrap_or_else(|err| panic!("{sql}: {err:?}"))
    {
        QueryResult::Rows { columns, .. } => columns.iter().map(|c| c.name.clone()).collect(),
        _ => panic!("expected rows"),
    }
}

#[test]
fn checkpointer_and_wal_shell_views_have_pg_columns() {
    let mut e = Engine::new();
    assert_eq!(
        col_names(&mut e, "SELECT * FROM pg_catalog.pg_stat_checkpointer"),
        vec![
            "num_timed",
            "num_requested",
            "num_done",
            "restartpoints_timed",
            "restartpoints_req",
            "restartpoints_done",
            "write_time",
            "sync_time",
            "buffers_written",
            "slru_written",
            "stats_reset",
        ]
    );
    assert_eq!(
        col_names(&mut e, "SELECT * FROM pg_catalog.pg_stat_wal"),
        vec![
            "wal_records",
            "wal_fpi",
            "wal_bytes",
            "wal_buffers_full",
            "stats_reset"
        ]
    );
    // Projection works too (via the meta-view pipeline).
    assert_eq!(
        col_names(
            &mut e,
            "SELECT wal_records, wal_bytes FROM pg_catalog.pg_stat_wal"
        ),
        vec!["wal_records", "wal_bytes"]
    );
}

#[test]
fn slru_and_subscription_stats_shell_views() {
    // v7.38 (read01 P3.15) — pg_stat_slru / pg_stat_subscription_stats
    // shell views with PG columns (empty: SPG has no SLRU + doesn't track
    // subscription stats yet).
    let mut e = Engine::new();
    assert_eq!(
        col_names(&mut e, "SELECT * FROM pg_catalog.pg_stat_slru"),
        vec![
            "name",
            "blks_zeroed",
            "blks_hit",
            "blks_read",
            "blks_written",
            "blks_exists",
            "flushes",
            "truncates",
            "stats_reset",
        ]
    );
    assert_eq!(
        col_names(
            &mut e,
            "SELECT * FROM pg_catalog.pg_stat_subscription_stats"
        ),
        vec![
            "subid",
            "subname",
            "apply_error_count",
            "sync_error_count",
            "confl_insert_exists",
            "confl_update_origin_differs",
            "confl_update_exists",
            "confl_update_missing",
            "confl_delete_origin_differs",
            "confl_delete_missing",
            "confl_multiple_unique_conflicts",
            "stats_reset",
        ]
    );
}

#[test]
fn catalog_views_resolve_without_pg_catalog_qualifier() {
    // v7.38 (read01 P3.21) — bare catalog names resolve like PG's implicit
    // pg_catalog search_path; they no longer require the pg_catalog. prefix.
    let mut e = Engine::new();
    for v in [
        "pg_stat_database",
        "pg_stat_user_tables",
        "pg_stat_checkpointer",
        "pg_stat_wal",
        "pg_stat_slru",
        "pg_replication_slots",
        "pg_statistic",
        "pg_stat_activity",
    ] {
        e.execute(&format!("SELECT * FROM {v}"))
            .unwrap_or_else(|err| panic!("bare {v}: {err:?}"));
    }
    // A user table whose name starts with pg_ but isn't a known catalog
    // view still resolves as the user's table.
    e.execute("CREATE TABLE pg_myapp(id int)").unwrap();
    e.execute("INSERT INTO pg_myapp VALUES(1)").unwrap();
    assert!(matches!(
        e.execute("SELECT count(*)::int FROM pg_myapp").unwrap(),
        QueryResult::Rows { .. }
    ));
}