test(database) :: test that parameters reach the DB and are cached

Before a bound parameter had to survive a round trip in `tests/transactions` and in `computed_projection_binding_order.sql`, but nothing bound one variable twice in a single statement, and nothing asserted that a parameterized page runs as a prepared statement rather than through `SQLExecDirect`.

Now two tests cover both halves of [sqlx-oldapi#57](sqlpage/sqlx-oldapi#57), one of wich covers the `INSERT ... SELECT $x WHERE $x IS NOT NULL` shape from #1474.

Author: 81reap

tests/mod.rs

@@ -9,6 +9,7 @@ mod exec;
 mod oidc;
 mod requests;
 mod server_timing;
+mod parameter_binding;
 pub mod sql_test_files;
 mod transactions;
 mod uploads;

tests/parameter_binding/echo_parameter.sql

@@ -0,0 +1 @@
+select 'text' as component, max(n) as contents from (select $x as n) as t;

tests/parameter_binding/mod.rs

@@ -0,0 +1,64 @@
+use actix_web::{http::StatusCode, test};
+use sqlx::any::AnyKind;
+use sqlx::connection::Connection as _;
+
+use sqlpage::webserver::database::SupportedDatabase;
+use sqlpage::webserver::http::main_handler;
+
+use crate::common::{get_request_to_with_data, make_app_data};
+
+async fn rendered_page(
+    path: &str,
+    data: actix_web::web::Data<sqlpage::AppState>,
+) -> actix_web::Result<String> {
+    let req = get_request_to_with_data(path, data).await?.to_srv_request();
+    let resp = main_handler(req).await?;
+    assert_eq!(resp.status(), StatusCode::OK);
+    Ok(String::from_utf8(test::read_body(resp).await.to_vec()).unwrap())
+}
+
+#[actix_web::test]
+async fn test_a_parameter_in_a_projection_reaches_the_database() -> actix_web::Result<()> {
+    let data = make_app_data().await;
+    let path = match data.db.info.database_type {
+        SupportedDatabase::Mssql => "/tests/parameter_binding/parameter_in_projection_mssql.sql",
+        SupportedDatabase::Oracle => return Ok(()), // no CREATE TEMPORARY TABLE
+        _ => "/tests/parameter_binding/parameter_in_projection.sql",
+    };
+
+    let page = rendered_page(&format!("{path}?x=1447"), data).await?;
+    assert!(
+        page.contains("1447"),
+        "{page}\nexpected the bound parameter to reach the inserted row"
+    );
+    Ok(())
+}
+
+#[actix_web::test]
+async fn test_parameterized_pages_leave_a_prepared_statement_in_the_cache() -> actix_web::Result<()>
+{
+    let data = make_app_data().await;
+    if data.db.info.kind == AnyKind::Mssql {
+        return Ok(()); // the MSSQL backend keeps no statement cache
+    }
+
+    for _ in 0..3 {
+        let page = rendered_page(
+            "/tests/parameter_binding/echo_parameter.sql?x=1447",
+            data.clone(),
+        )
+        .await?;
+        assert!(
+            page.contains("1447"),
+            "{page}\nexpected the bound parameter to reach the query"
+        );
+    }
+
+    let connection = data.db.connection.acquire().await.unwrap();
+    assert!(
+        connection.cached_statements_size() > 0,
+        "{:?} ran a parameterized query three times without caching a prepared statement",
+        data.db.info.kind
+    );
+    Ok(())
+}

tests/parameter_binding/parameter_in_projection.sql

@@ -0,0 +1,8 @@
+DROP TABLE IF EXISTS sqlpage_param_projection;
+CREATE TEMPORARY TABLE sqlpage_param_projection(username VARCHAR(100) NOT NULL);
+
+INSERT INTO sqlpage_param_projection (username)
+SELECT $x
+WHERE $x IS NOT NULL;
+
+select 'text' as component, max(username) as contents from sqlpage_param_projection;

tests/parameter_binding/parameter_in_projection_mssql.sql

@@ -0,0 +1,8 @@
+DROP TABLE IF EXISTS #sqlpage_param_projection;
+CREATE TABLE #sqlpage_param_projection(username VARCHAR(100) NOT NULL);
+
+INSERT INTO #sqlpage_param_projection (username)
+SELECT $x
+WHERE $x IS NOT NULL;
+
+select 'text' as component, max(username) as contents from #sqlpage_param_projection;