Use an even more minimal health check

Author: sfackler

src/lib.rs

@@ -44,7 +44,7 @@ impl r2d2::PoolManager<PostgresConnection, Error> for PostgresPoolManager {
     }
 
     fn is_valid(&self, conn: &mut PostgresConnection) -> Result<(), Error> {
-        conn.batch_execute("SELECT 1").map_err(OtherError)
+        conn.batch_execute("").map_err(OtherError)
     }
 
     fn has_broken(&self, conn: &mut PostgresConnection) -> bool {

tests/test.rs

@@ -68,3 +68,17 @@ fn test_basic() {
 
     pool.get().unwrap();
 }
+
+#[test]
+fn test_is_valid() {
+    let manager = PostgresPoolManager::new("postgres://postgres@localhost", NoSsl);
+    let config = r2d2::Config {
+        pool_size: 1,
+        test_on_check_out: true,
+        ..Default::default()
+    };
+    let handler = r2d2::NoopErrorHandler;
+    let pool = r2d2::Pool::new(config, manager, handler).unwrap();
+
+    pool.get().unwrap();
+}