refactor(database): address transaction helper review feedback

- document disabled transaction pass-through behavior
- log original callback exception when rollback throws
- remove stale DBDebug test helper warning

Signed-off-by: memleakd <121398829+memleakd@users.noreply.github.com>

Author: memleakd

system/Database/BaseConnection.php

@@ -1090,6 +1090,10 @@ public function transaction(callable $callback): mixed
         } catch (Throwable $e) {
             try {
                 $this->transRollback();
+            } catch (Throwable $rollbackException) {
+                log_message('error', 'Database: Transaction callback threw an exception before rollback failed: ' . $e);
+
+                throw $rollbackException;
             } finally {
                 if ($this->transDepth > 0) {
                     $this->transStatus = false;

tests/system/Database/Live/TransactionClosureTest.php

@@ -42,8 +42,6 @@ protected function setUp(): void
 
     /**
      * Sets $DBDebug to false.
-     *
-     * WARNING: this value will persist! take care to roll it back.
      */
     protected function disableDBDebug(): void
     {
@@ -211,6 +209,7 @@ public function testRollbackCallbackExceptionBubblesWhenCallbackExceptionTrigger
             $this->assertSame('Rollback callback failed.', $e->getMessage());
         }
 
+        $this->assertLogContains('error', 'Transaction callback failed.');
         $this->dontSeeInDatabase('job', ['name' => 'Rolled Back Job']);
     }
 

user_guide_src/source/database/transactions.rst

@@ -68,6 +68,9 @@ return value. If the transaction cannot begin, or if a query failure marks the
 transaction as failed without throwing an exception, ``transaction()`` rolls
 back and returns ``false``.
 
+If transactions are disabled, ``transaction()`` does not start a transaction.
+It runs the callback and returns the callback result.
+
 If the callback throws an exception, ``transaction()`` rolls back and rethrows
 the original exception.