#[cfg(test)]
mod tests {
use proptest::{option, prelude::*};
use crate::{canonical::canonical_key, lower::parse_and_lower, parse_select};
const TABLES: &[&str] = &["posts", "authors", "comments"];
const COLUMNS: &[&str] = &["id", "author_id", "created_at", "title"];
const CTE_NAMES: &[&str] = &["recent_posts", "visible_posts", "filtered_posts"];
proptest! {
#[test]
fn parse_unparse_reparse_round_trips(query in supported_select()) {
let statement = parse_select(&query)?;
let rendered = statement.to_string();
let reparsed = parse_select(&rendered)?;
prop_assert_eq!(statement, reparsed);
}
#[test]
fn alpha_renaming_cte_preserves_canonical_key((left_name, right_name) in distinct_cte_names()) {
let left = cte_query(&left_name);
let right = cte_query(&right_name);
let left = parse_and_lower(&left)?;
let right = parse_and_lower(&right)?;
prop_assert_eq!(canonical_key(&left), canonical_key(&right));
}
}
fn supported_select() -> impl Strategy<Value = String> {
(
select_list(),
table_name(),
option::of(predicate()),
option::of(order_limit()),
)
.prop_map(|(projection, table, predicate, order_limit)| {
let mut query = format!("SELECT {projection} FROM {table}");
if let Some(predicate) = predicate {
query.push_str(" WHERE ");
query.push_str(&predicate);
}
if let Some(order_limit) = order_limit {
query.push(' ');
query.push_str(&order_limit);
}
query
})
}
fn select_list() -> impl Strategy<Value = String> {
prop::collection::vec(column_name(), 1..=3).prop_map(|columns| columns.join(", "))
}
fn predicate() -> impl Strategy<Value = String> {
(column_name(), 0_i64..1000).prop_map(|(column, value)| format!("{column} = {value}"))
}
fn order_limit() -> impl Strategy<Value = String> {
(column_name(), any::<bool>(), 1_u16..100).prop_map(|(column, descending, limit)| {
let direction = if descending { " DESC" } else { "" };
format!("ORDER BY {column}{direction} LIMIT {limit}")
})
}
fn table_name() -> impl Strategy<Value = String> {
prop::sample::select(TABLES).prop_map(str::to_owned)
}
fn column_name() -> impl Strategy<Value = String> {
prop::sample::select(COLUMNS).prop_map(str::to_owned)
}
fn distinct_cte_names() -> impl Strategy<Value = (String, String)> {
(
prop::sample::select(CTE_NAMES),
prop::sample::select(CTE_NAMES),
)
.prop_filter("CTE names must differ", |(left, right)| left != right)
.prop_map(|(left, right)| (left.to_owned(), right.to_owned()))
}
fn cte_query(name: &str) -> String {
format!(
"WITH {name} AS (
SELECT id FROM posts WHERE author_id = 42
)
SELECT id FROM {name}"
)
}
}