[Mailer] Change the syntax for DSNs using failover or roundrobin

fabpot · fabpot · commit b026b86f3aa7 · 2019-09-06T16:21:30.000+02:00
diff --git a/src/Symfony/Component/Mailer/CHANGELOG.md b/src/Symfony/Component/Mailer/CHANGELOG.md
@@ -4,6 +4,18 @@ CHANGELOG
 4.4.0
 -----
 
+ * [BC BREAK] changed the syntax for failover and roundrobin DSNs
+
+   Before:
+
+   dummy://a || dummy://b (for failover)
+   dummy://a && dummy://b (for roundrobin)
+
+   After:
+
+   failover(dummy://a dummy://b)
+   roundrobin(dummy://a dummy://b)
+
  * added support for multiple transports on a `Mailer` instance
  * [BC BREAK] removed the `auth_mode` DSN option (it is now always determined automatically)
  * STARTTLS cannot be enabled anymore (it is used automatically if TLS is disabled and the server supports STARTTLS)
diff --git a/src/Symfony/Component/Mailer/Tests/TransportTest.php b/src/Symfony/Component/Mailer/Tests/TransportTest.php
@@ -44,14 +44,19 @@ public function fromStringProvider(): iterable
         ];
 
         yield 'failover transport' => [
-            'dummy://a || dummy://b',
+            'failover(dummy://a dummy://b)',
             new FailoverTransport([$transportA, $transportB]),
         ];
 
         yield 'round robin transport' => [
-            'dummy://a && dummy://b',
+            'roundrobin(dummy://a dummy://b)',
             new RoundRobinTransport([$transportA, $transportB]),
         ];
+
+        yield 'mixed transport' => [
+            'roundrobin(dummy://a failover(dummy://b dummy://a) dummy://b)',
+            new RoundRobinTransport([$transportA, new FailoverTransport([$transportB, $transportA]), $transportB]),
+        ];
     }
 }
 
diff --git a/src/Symfony/Component/Mailer/Transport.php b/src/Symfony/Component/Mailer/Transport.php
@@ -18,6 +18,7 @@
 use Symfony\Component\Mailer\Bridge\Mailgun\Transport\MailgunTransportFactory;
 use Symfony\Component\Mailer\Bridge\Postmark\Transport\PostmarkTransportFactory;
 use Symfony\Component\Mailer\Bridge\Sendgrid\Transport\SendgridTransportFactory;
+use Symfony\Component\Mailer\Exception\InvalidArgumentException;
 use Symfony\Component\Mailer\Exception\UnsupportedHostException;
 use Symfony\Component\Mailer\Transport\Dsn;
 use Symfony\Component\Mailer\Transport\FailoverTransport;
@@ -82,17 +83,54 @@ public function fromStrings(array $dsns): Transports
 
     public function fromString(string $dsn): TransportInterface
     {
-        $dsns = preg_split('/\s++\|\|\s++/', $dsn);
-        if (\count($dsns) > 1) {
-            return new FailoverTransport($this->createFromDsns($dsns));
+        list($transport, $offset) = $this->parseDsn($dsn);
+        if ($offset !== strlen($dsn)) {
+            throw new InvalidArgumentException(sprintf('The DSN has some garbage at the end: %s.', substr($dsn, $offset)));
         }
 
-        $dsns = preg_split('/\s++&&\s++/', $dsn);
-        if (\count($dsns) > 1) {
-            return new RoundRobinTransport($this->createFromDsns($dsns));
-        }
+        return $transport;
+    }
+
+    private function parseDsn(string $dsn, int $offset = 0): array {
+        static $maps = [
+            'failover' => FailoverTransport::class,
+            'roundrobin' => RoundRobinTransport::class,
+        ];
+
+        while (true) {
+            foreach ($maps as $name => $class) {
+                $name .= '(';
+                if ($name === substr($dsn, $offset, strlen($name))) {
+                    $offset += strlen($name) - 1;
+                    preg_match('{\(([^()]|(?R))*\)}A', $dsn, $matches, 0, $offset);
+                    if (!isset($matches[0])) {
+                        continue;
+                    }
+
+                    ++$offset;
+                    $args = [];
+                    while (true) {
+                        list($arg, $offset) = $this->parseDsn($dsn, $offset);
+                        $args[] = $arg;
+                        if (strlen($dsn) === $offset) {
+                            break;
+                        }
+                        ++$offset;
+                        if (')' === $dsn[$offset - 1]) {
+                            break;
+                        }
+                    }
+
+                    return [new $class($args), $offset];
+                }
+            }
 
-        return $this->fromDsnObject(Dsn::fromString($dsn));
+            if ($pos = strcspn($dsn, ' )', $offset)) {
+                return [$this->fromDsnObject(Dsn::fromString(substr($dsn, $offset, $pos))), $offset + $pos];
+            }
+
+            return [$this->fromDsnObject(Dsn::fromString(substr($dsn, $offset))), strlen($dsn)];
+        }
     }
 
     public function fromDsnObject(Dsn $dsn): TransportInterface
@@ -106,21 +144,6 @@ public function fromDsnObject(Dsn $dsn): TransportInterface
         throw new UnsupportedHostException($dsn);
     }
 
-    /**
-     * @param string[] $dsns
-     *
-     * @return TransportInterface[]
-     */
-    private function createFromDsns(array $dsns): array
-    {
-        $transports = [];
-        foreach ($dsns as $dsn) {
-            $transports[] = $this->fromDsnObject(Dsn::fromString($dsn));
-        }
-
-        return $transports;
-    }
-
     private static function getDefaultFactories(EventDispatcherInterface $dispatcher = null, HttpClientInterface $client = null, LoggerInterface $logger = null): iterable
     {
         foreach (self::FACTORY_CLASSES as $factoryClass) {
