feat: Add a callback to be called on transaction failure

Author: dshafik

src/Illuminate/Database/Concerns/ManagesTransactions.php

@@ -20,7 +20,7 @@ trait ManagesTransactions
      *
      * @throws \Throwable
      */
-    public function transaction(Closure $callback, $attempts = 1)
+    public function transaction(Closure $callback, $attempts = 1, ?Closure $onFailureCallback = null)
     {
         for ($currentAttempt = 1; $currentAttempt <= $attempts; $currentAttempt++) {
             $this->beginTransaction();
@@ -37,7 +37,7 @@ public function transaction(Closure $callback, $attempts = 1)
             // exception back out, and let the developer handle an uncaught exception.
             catch (Throwable $e) {
                 $this->handleTransactionException(
-                    $e, $currentAttempt, $attempts
+                    $e, $currentAttempt, $attempts, $onFailureCallback
                 );
 
                 continue;
@@ -78,11 +78,12 @@ public function transaction(Closure $callback, $attempts = 1)
      * @param  \Throwable  $e
      * @param  int  $currentAttempt
      * @param  int  $maxAttempts
+     * @param Closure|null $onFailureCallback
      * @return void
      *
      * @throws \Throwable
      */
-    protected function handleTransactionException(Throwable $e, $currentAttempt, $maxAttempts)
+    protected function handleTransactionException(Throwable $e, $currentAttempt, $maxAttempts, ?Closure $onFailureCallback)
     {
         // On a deadlock, MySQL rolls back the entire transaction so we can't just
         // retry the query. We have to throw this exception all the way out and
@@ -108,6 +109,10 @@ protected function handleTransactionException(Throwable $e, $currentAttempt, $ma
             return;
         }
 
+        if ($onFailureCallback !== null) {
+            $onFailureCallback($e);
+        }
+
         throw $e;
     }
 

tests/Integration/Database/DatabaseTransactionsTest.php

@@ -105,6 +105,42 @@ public function testTransactionsDoNotAffectDifferentConnections()
         $this->assertTrue($secondObject->ran);
         $this->assertFalse($thirdObject->ran);
     }
+
+    public function testOnErrorCallbackIsCalled()
+    {
+        $executed = false;
+        try {
+            DB::transaction(function () {
+                throw new \Exception;
+            }, 1, function () use (&$executed) {
+                $executed = true;
+            });
+        } catch (\Throwable) {
+            // Ignore the exception
+        }
+
+        $this->assertTrue($executed);
+    }
+
+    public function testOnErrorCallbackIsCalledWithDeadlockRetry()
+    {
+        $executed = false;
+        $attempts = 0;
+
+        try {
+            DB::transaction(function () use (&$attempts) {
+                $attempts += 1;
+                throw new \Exception('has been chosen as the deadlock victim');
+            }, 3, function () use (&$executed) {
+                $executed = true;
+            });
+        } catch (\Throwable) {
+            // Ignore the exception
+        }
+
+        $this->assertSame(3, $attempts);
+        $this->assertTrue($executed);
+    }
 }
 
 class TestObjectForTransactions