From 6ade6a89e60d7334d31b8486440bc99fe30cbf17 Mon Sep 17 00:00:00 2001
From: Fernando Correa de Oliveira <fernandocorrea@gmail.com>
Date: Mon, 30 Aug 2021 00:22:45 +0100
Subject: [PATCH] WiP: first test to try to resolve #507

If `red-do :transaction`'s block returns a Awaitable, it creates
a new Promise that will handle the commit/rollback and does not
let the sync code to call commit/rollback.

Probable next steps are:
- extract that logic to a transaction manager
- on transaction manager add a transaction stack and methods
	- queue-begin
	- unqueue-commit
	- break-queue-rollback
(or something like that)
---
 lib/Red/Do.pm6 | 25 ++++++++++++++++++++++---
 1 file changed, 22 insertions(+), 3 deletions(-)

diff --git a/lib/Red/Do.pm6 b/lib/Red/Do.pm6
index 21dd052a..a57471bc 100644
--- a/lib/Red/Do.pm6
+++ b/lib/Red/Do.pm6
@@ -130,9 +130,28 @@ multi red-do(
         *%pars where *.none.key eq "with"
 ) is export {
     my $conn = get-RED-DB.begin;
-    KEEP $conn.commit;
-    UNDO $conn.rollback;
-    red-do |@blocks, :$async, |%pars, :with($conn);
+    CATCH {
+        default {
+            UNDO $conn.rollback;
+            .rethrow
+        }
+    }
+    given red-do |@blocks, :$async, |%pars, :with($conn) {
+        when Promise {
+            start {
+                KEEP $conn.commit;
+                UNDO $conn.rollback;
+                .result
+            }
+        }
+        when !*.DEFINITE {
+            UNDO $conn.rollback;
+            $_
+        }
+        when *.DEFINITE {
+            $_
+        }
+    }
 }
 
 #| Receives list of pairs with connection name and block