Add a mail() hook to NativeMailHandler. (#1948)

Allows subclassing NativeMailHandler so that the call to mail()
can be intercepted and replaced in cases where additional processing
needs to happen.

Tests are mostly updated to use this method to test sent messages,
but one test is added to make sure that everything gets passed through
intact.

Co-authored-by: JDW <xs@jdw.sx>

src/Monolog/Handler/NativeMailerHandler.php

@@ -128,7 +128,7 @@ class NativeMailerHandler extends MailHandler
 
         $parameters = implode(' ', $this->parameters);
         foreach ($this->to as $to) {
-            mail($to, $subject, $content, $headers, $parameters);
+            $this->mail($to, $subject, $content, $headers, $parameters);
         }
     }
 
@@ -170,4 +170,10 @@ class NativeMailerHandler extends MailHandler
 
         return $this;
     }
+
+
+    protected function mail(string $to, string $subject, string $content, string $headers, string $parameters): void
+    {
+        mail($to, $subject, $content, $headers, $parameters);
+    }
 }

tests/Monolog/Handler/NativeMailerHandlerTest.php

@@ -26,6 +26,21 @@ class NativeMailerHandlerTest extends TestCase
         $GLOBALS['mail'] = [];
     }
 
+    protected function newNativeMailerHandler( ... $args ) : NativeMailerHandler
+    {
+        return new class( ... $args ) extends NativeMailerHandler {
+
+            public $mail = [];
+
+            protected function mail( string $to, string $subject, string $content,
+                                     string $headers, string $parameters ) : void
+            {
+                $this->mail[] = \func_get_args();
+            }
+
+        };
+    }
+
     public function testConstructorHeaderInjection()
     {
         $this->expectException(\InvalidArgumentException::class);
@@ -71,19 +86,19 @@ class NativeMailerHandlerTest extends TestCase
         $subject = 'dear victim';
         $from = 'receiver@example.org';
 
-        $mailer = new NativeMailerHandler($to, $subject, $from);
+        $mailer = $this->newNativeMailerHandler($to, $subject, $from);
         $mailer->setFormatter(new \Monolog\Formatter\LineFormatter);
         $mailer->handleBatch([]);
 
         // batch is empty, nothing sent
-        $this->assertEmpty($GLOBALS['mail']);
+        $this->assertEmpty($mailer->mail);
 
         // non-empty batch
         $mailer->handle($this->getRecord(Level::Error, "Foo\nBar\r\n\r\nBaz"));
-        $this->assertNotEmpty($GLOBALS['mail']);
-        $this->assertIsArray($GLOBALS['mail']);
-        $this->assertArrayHasKey('0', $GLOBALS['mail']);
-        $params = $GLOBALS['mail'][0];
+        $this->assertNotEmpty($mailer->mail);
+        $this->assertIsArray($mailer->mail);
+        $this->assertArrayHasKey('0', $mailer->mail);
+        $params = $mailer->mail[0];
         $this->assertCount(5, $params);
         $this->assertSame($to, $params[0]);
         $this->assertSame($subject, $params[1]);
@@ -94,13 +109,30 @@ class NativeMailerHandlerTest extends TestCase
 
     public function testMessageSubjectFormatting()
     {
-        $mailer = new NativeMailerHandler('to@example.org', 'Alert: %level_name% %message%', 'from@example.org');
+        $mailer = $this->newNativeMailerHandler('to@example.org', 'Alert: %level_name% %message%', 'from@example.org');
         $mailer->handle($this->getRecord(Level::Error, "Foo\nBar\r\n\r\nBaz"));
+        $this->assertNotEmpty($mailer->mail);
+        $this->assertIsArray($mailer->mail);
+        $this->assertArrayHasKey('0', $mailer->mail);
+        $params = $mailer->mail[0];
+        $this->assertCount(5, $params);
+        $this->assertSame('Alert: ERROR Foo Bar  Baz', $params[1]);
+    }
+
+    public function testMail()
+    {
+        $mailer = new NativeMailerHandler('to@example.org', 'subject', 'from@example.org' );
+        $mailer->addParameter( 'foo' );
+        $mailer->handle($this->getRecord(Level::Error, "FooBarBaz"));
         $this->assertNotEmpty($GLOBALS['mail']);
         $this->assertIsArray($GLOBALS['mail']);
         $this->assertArrayHasKey('0', $GLOBALS['mail']);
         $params = $GLOBALS['mail'][0];
         $this->assertCount(5, $params);
-        $this->assertSame('Alert: ERROR Foo Bar  Baz', $params[1]);
+        $this->assertSame('to@example.org', $params[0]);
+        $this->assertSame('subject', $params[1]);
+        $this->assertStringContainsString("FooBarBaz", $params[2]);
+        $this->assertStringContainsString( 'From: from@example.org', $params[3] );
+        $this->assertSame( 'foo', $params[4] );
     }
 }