feature #33456 [MonologBridge] Add Mailer handler (BoShurik)

This PR was merged into the 5.1-dev branch.

Discussion
----------

[MonologBridge] Add Mailer handler

| Q             | A
| ------------- | ---
| Branch?       | 4.4
| Bug fix?      | no
| New feature?  | yes <!-- please update src/**/CHANGELOG.md files -->
| BC breaks?    | no     <!-- see https://symfony.com/bc -->
| Deprecations? | no <!-- please update UPGRADE-*.md and src/**/CHANGELOG.md files -->
| Tests pass?   | yes    <!-- please add some, will be required by reviewers -->
| Fixed tickets | #33209   <!-- #-prefixed issue number(s), if any -->
| License       | MIT
| Doc PR        | - <!-- required for new features -->

<!--
Replace this notice by a short README for your feature/bugfix. This will help people
understand your PR and can be used as a start for the documentation.

Additionally (see https://symfony.com/roadmap):
 - Bug fixes must be submitted against the lowest maintained branch where they apply
   (lowest branches are regularly merged to upper ones so they get the fixes too).
 - Features and deprecations must be submitted against branch 4.4.
 - Legacy code removals go to the master branch.
-->

Commits
-------

5b7393b Add monolog mailer handler

src/Symfony/Bridge/Monolog/CHANGELOG.md

@@ -1,6 +1,10 @@
 CHANGELOG
 =========
 
+5.1.0
+-----
+ * Added `MailerHandler`
+
 5.0.0
 -----
 

src/Symfony/Bridge/Monolog/Handler/MailerHandler.php

@@ -0,0 +1,143 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Bridge\Monolog\Handler;
+
+use Monolog\Formatter\FormatterInterface;
+use Monolog\Formatter\HtmlFormatter;
+use Monolog\Formatter\LineFormatter;
+use Monolog\Handler\AbstractProcessingHandler;
+use Monolog\Logger;
+use Symfony\Component\Mailer\MailerInterface;
+use Symfony\Component\Mime\Email;
+
+/**
+ * @author Alexander Borisov <boshurik@gmail.com>
+ */
+class MailerHandler extends AbstractProcessingHandler
+{
+    private $mailer;
+
+    private $messageTemplate;
+
+    /**
+     * @param callable|Email $messageTemplate
+     */
+    public function __construct(MailerInterface $mailer, $messageTemplate, int $level = Logger::DEBUG, bool $bubble = true)
+    {
+        parent::__construct($level, $bubble);
+
+        $this->mailer = $mailer;
+        $this->messageTemplate = $messageTemplate;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function handleBatch(array $records): void
+    {
+        $messages = [];
+
+        foreach ($records as $record) {
+            if ($record['level'] < $this->level) {
+                continue;
+            }
+            $messages[] = $this->processRecord($record);
+        }
+
+        if (!empty($messages)) {
+            $this->send((string) $this->getFormatter()->formatBatch($messages), $messages);
+        }
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function write(array $record): void
+    {
+        $this->send((string) $record['formatted'], [$record]);
+    }
+
+    /**
+     * Send a mail with the given content.
+     *
+     * @param string $content formatted email body to be sent
+     * @param array  $records the array of log records that formed this content
+     */
+    protected function send(string $content, array $records)
+    {
+        $this->mailer->send($this->buildMessage($content, $records));
+    }
+
+    /**
+     * Gets the formatter for the Message subject.
+     *
+     * @param string $format The format of the subject
+     */
+    protected function getSubjectFormatter(string $format): FormatterInterface
+    {
+        return new LineFormatter($format);
+    }
+
+    /**
+     * Creates instance of Message to be sent.
+     *
+     * @param string $content formatted email body to be sent
+     * @param array  $records Log records that formed the content
+     */
+    protected function buildMessage(string $content, array $records): Email
+    {
+        $message = null;
+        if ($this->messageTemplate instanceof Email) {
+            $message = clone $this->messageTemplate;
+        } elseif (\is_callable($this->messageTemplate)) {
+            $message = \call_user_func($this->messageTemplate, $content, $records);
+            if (!$message instanceof Email) {
+                throw new \InvalidArgumentException(sprintf('Could not resolve message from a callable. Instance of "%s" is expected', Email::class));
+            }
+        } else {
+            throw new \InvalidArgumentException('Could not resolve message as instance of Email or a callable returning it');
+        }
+
+        if ($records) {
+            $subjectFormatter = $this->getSubjectFormatter($message->getSubject());
+            $message->subject($subjectFormatter->format($this->getHighestRecord($records)));
+        }
+
+        if ($this->getFormatter() instanceof HtmlFormatter) {
+            if ($message->getHtmlCharset()) {
+                $message->html($content, $message->getHtmlCharset());
+            } else {
+                $message->html($content);
+            }
+        } else {
+            if ($message->getTextCharset()) {
+                $message->text($content, $message->getTextCharset());
+            } else {
+                $message->text($content);
+            }
+        }
+
+        return $message;
+    }
+
+    protected function getHighestRecord(array $records): array
+    {
+        $highestRecord = null;
+        foreach ($records as $record) {
+            if (null === $highestRecord || $highestRecord['level'] < $record['level']) {
+                $highestRecord = $record;
+            }
+        }
+
+        return $highestRecord;
+    }
+}

src/Symfony/Bridge/Monolog/Tests/Handler/MailerHandlerTest.php

@@ -0,0 +1,123 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Bridge\Monolog\Tests\Handler;
+
+use Monolog\Formatter\HtmlFormatter;
+use Monolog\Formatter\LineFormatter;
+use PHPUnit\Framework\MockObject\MockObject;
+use PHPUnit\Framework\TestCase;
+use Symfony\Bridge\Monolog\Handler\MailerHandler;
+use Symfony\Bridge\Monolog\Logger;
+use Symfony\Component\Mailer\MailerInterface;
+use Symfony\Component\Mime\Email;
+
+class MailerHandlerTest extends TestCase
+{
+    /** @var MockObject|MailerInterface */
+    private $mailer = null;
+
+    protected function setUp(): void
+    {
+        $this->mailer = $this->createMock(MailerInterface::class);
+    }
+
+    public function testHandle()
+    {
+        $handler = new MailerHandler($this->mailer, (new Email())->subject('Alert: %level_name% %message%'));
+        $handler->setFormatter(new LineFormatter());
+        $this->mailer
+            ->expects($this->once())
+            ->method('send')
+            ->with($this->callback(function (Email $email) {
+                return 'Alert: WARNING message' === $email->getSubject() && null === $email->getHtmlBody();
+            }))
+        ;
+        $handler->handle($this->getRecord(Logger::WARNING, 'message'));
+    }
+
+    public function testHandleBatch()
+    {
+        $handler = new MailerHandler($this->mailer, (new Email())->subject('Alert: %level_name% %message%'));
+        $handler->setFormatter(new LineFormatter());
+        $this->mailer
+            ->expects($this->once())
+            ->method('send')
+            ->with($this->callback(function (Email $email) {
+                return 'Alert: ERROR error' === $email->getSubject() && null === $email->getHtmlBody();
+            }))
+        ;
+        $handler->handleBatch($this->getMultipleRecords());
+    }
+
+    public function testMessageCreationIsLazyWhenUsingCallback()
+    {
+        $this->mailer
+            ->expects($this->never())
+            ->method('send')
+        ;
+
+        $callback = function () {
+            throw new \RuntimeException('Email creation callback should not have been called in this test');
+        };
+        $handler = new MailerHandler($this->mailer, $callback, Logger::ALERT);
+
+        $records = [
+            $this->getRecord(Logger::DEBUG),
+            $this->getRecord(Logger::INFO),
+        ];
+        $handler->handleBatch($records);
+    }
+
+    public function testHtmlContent()
+    {
+        $handler = new MailerHandler($this->mailer, (new Email())->subject('Alert: %level_name% %message%'));
+        $handler->setFormatter(new HtmlFormatter());
+        $this->mailer
+            ->expects($this->once())
+            ->method('send')
+            ->with($this->callback(function (Email $email) {
+                return 'Alert: WARNING message' === $email->getSubject() && null === $email->getTextBody();
+            }))
+        ;
+        $handler->handle($this->getRecord(Logger::WARNING, 'message'));
+    }
+
+    /**
+     * @return array Record
+     */
+    protected function getRecord($level = Logger::WARNING, $message = 'test', $context = [])
+    {
+        return [
+            'message' => $message,
+            'context' => $context,
+            'level' => $level,
+            'level_name' => Logger::getLevelName($level),
+            'channel' => 'test',
+            'datetime' => \DateTime::createFromFormat('U.u', sprintf('%.6F', microtime(true))),
+            'extra' => [],
+        ];
+    }
+
+    /**
+     * @return array
+     */
+    protected function getMultipleRecords()
+    {
+        return [
+            $this->getRecord(Logger::DEBUG, 'debug message 1'),
+            $this->getRecord(Logger::DEBUG, 'debug message 2'),
+            $this->getRecord(Logger::INFO, 'information'),
+            $this->getRecord(Logger::WARNING, 'warning'),
+            $this->getRecord(Logger::ERROR, 'error'),
+        ];
+    }
+}

src/Symfony/Bridge/Monolog/composer.json

@@ -25,7 +25,9 @@
         "symfony/console": "^4.4|^5.0",
         "symfony/http-client": "^4.4|^5.0",
         "symfony/security-core": "^4.4|^5.0",
-        "symfony/var-dumper": "^4.4|^5.0"
+        "symfony/var-dumper": "^4.4|^5.0",
+        "symfony/mailer": "^4.4|^5.0",
+        "symfony/mime": "^4.4|^5.0"
     },
     "conflict": {
         "symfony/console": "<4.4",