feat: add is_really_closed feature to non-async postgres lib

Author: conradludgate

postgres/src/client.rs

@@ -422,6 +422,11 @@ impl Client {
         self.connection.block_on(self.client.batch_execute(query))
     }
 
+    /// Check the connection is alive and wait for the confirmation.
+    pub fn check_connection(&mut self) -> Result<(), Error> {
+        self.connection.block_on(self.client.check_connection())
+    }
+
     /// Begins a new database transaction.
     ///
     /// The transaction will roll back by default - use the `commit` method to commit it.

postgres/src/test.rs

@@ -508,3 +508,24 @@ fn check_send() {
     is_send::<Statement>();
     is_send::<Transaction<'_>>();
 }
+
+#[test]
+fn is_closed() {
+    let mut client = Client::connect("host=localhost port=5433 user=postgres", NoTls).unwrap();
+    assert!(!client.is_closed());
+    client.check_connection().unwrap();
+
+    let row = client.query_one("select pg_backend_pid()", &[]).unwrap();
+    let pid: i32 = row.get(0);
+
+    {
+        let mut client2 = Client::connect("host=localhost port=5433 user=postgres", NoTls).unwrap();
+        client2
+            .query("SELECT pg_terminate_backend($1)", &[&pid])
+            .unwrap();
+    }
+
+    assert!(!client.is_closed());
+    client.check_connection().unwrap_err();
+    assert!(client.is_closed());
+}