postgres_query 0.2.1

use bytes::BytesMut;
use postgres_query::*;
use postgres_types::{IsNull, ToSql, Type};

#[test]
fn text_only() {
    let query = query!("SELECT id, name FROM people");

    assert_eq!(query.sql, "SELECT id, name FROM people");
    assert_params_eq(query.parameters, vec![])
}

#[test]
fn escape_dollar() {
    let query = query!("SELECT $$");

    assert_eq!(query.sql, "SELECT $");
    assert_params_eq(query.parameters, vec![])
}

#[test]
fn parameter_substitution_implicit_name() {
    let age = 42;
    let query = query!("SELECT id, name FROM people WHERE age = $age", age);

    assert_eq!(query.sql, "SELECT id, name FROM people WHERE age = $1");
    assert_params_eq(query.parameters, vec![(&age, &Type::INT4)])
}

#[test]
fn parameter_substitution_explicit_name() {
    let query = query!("SELECT id, name FROM people WHERE age = $age", age = 42);

    assert_eq!(query.sql, "SELECT id, name FROM people WHERE age = $1");
    assert_params_eq(query.parameters, vec![(&42, &Type::INT4)])
}

#[test]
fn parameter_substitution_multiple_parameters() {
    let query = query!("$a $b $c", a = 42, b = "John Wick", c = Option::<i32>::None,);

    assert_eq!(query.sql, "$1 $2 $3");
    assert_params_eq(
        query.parameters,
        vec![
            (&42, &Type::INT4),
            (&"John Wick", &Type::TEXT),
            (&Option::<i32>::None, &Type::INT4),
        ],
    )
}

fn assert_params_eq<'a>(a: Vec<&'a (dyn ToSql + Sync)>, b: Vec<(&'a dyn ToSql, &'a Type)>) {
    assert_eq!(a.len(), b.len());
    for (a, (b, ty)) in a.into_iter().zip(b) {
        sql_eq(a, b, ty);
    }
}

/// Check if two SQL values are of the same type and value
fn sql_eq(a: &dyn ToSql, b: &dyn ToSql, ty: &Type) -> bool {
    let mut a_buffer = BytesMut::new();
    let mut b_buffer = BytesMut::new();

    let a_result = a.to_sql_checked(ty, &mut a_buffer);
    let b_result = b.to_sql_checked(ty, &mut b_buffer);

    let is_null = |null| match null {
        IsNull::Yes => true,
        IsNull::No => false,
    };

    a_result.is_ok()
        && b_result.is_ok()
        && is_null(a_result.unwrap()) == is_null(b_result.unwrap())
        && a_buffer == b_buffer
}