feature #23707 [Monolog Bridge][DX] Add a Monolog activation strategy for ignoring specific HTTP codes (simshaun, fabpot)

This PR was merged into the 4.1-dev branch.

Discussion
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[Monolog Bridge][DX] Add a Monolog activation strategy for ignoring specific HTTP codes

| Q             | A
| ------------- | ---
| Branch?       | 3.4
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #9712
| License       | MIT
| Doc PR        | symfony/symfony-docs#8235

This PR introduces a Monolog activation strategy that makes it easy to ignore specific HTTP codes. e.g. Stopping logs from being flooded with 403s, 404s, and 405s.

Relevant Symfony integration PR on symfony/monolog-bundle: https://github.com/symfony/monolog-bundle/pull/221

Commits
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6fc1cc3ec3 added some validation
c11a8eb92e Add a Monolog activation strategy for ignoring specific HTTP codes

src/Symfony/Bridge/Monolog/Handler/FingersCrossed/HttpCodeActivationStrategy.php

@@ -0,0 +1,74 @@
+<?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\FingersCrossed;
+
+use Monolog\Handler\FingersCrossed\ErrorLevelActivationStrategy;
+use Symfony\Component\HttpKernel\Exception\HttpException;
+use Symfony\Component\HttpFoundation\RequestStack;
+
+/**
+ * Activation strategy that ignores certain HTTP codes.
+ *
+ * @author Shaun Simmons <shaun@envysphere.com>
+ */
+class HttpCodeActivationStrategy extends ErrorLevelActivationStrategy
+{
+    private $exclusions;
+    private $requestStack;
+
+    /**
+     * @param array $exclusions each exclusion must have a "code" and "urls" keys
+     */
+    public function __construct(RequestStack $requestStack, array $exclusions, $actionLevel)
+    {
+        foreach ($exclusions as $exclusion) {
+            if (!array_key_exists('code', $exclusion)) {
+                throw new \LogicException(sprintf('An exclusion must have a "code" key'));
+            }
+            if (!array_key_exists('urls', $exclusion)) {
+                throw new \LogicException(sprintf('An exclusion must have a "urls" key'));
+            }
+        }
+
+        parent::__construct($actionLevel);
+
+        $this->requestStack = $requestStack;
+        $this->exclusions = $exclusions;
+    }
+
+    public function isHandlerActivated(array $record)
+    {
+        $isActivated = parent::isHandlerActivated($record);
+
+        if (
+            $isActivated
+            && isset($record['context']['exception'])
+            && $record['context']['exception'] instanceof HttpException
+            && ($request = $this->requestStack->getMasterRequest())
+        ) {
+            foreach ($this->exclusions as $exclusion) {
+                if ($record['context']['exception']->getStatusCode() !== $exclusion['code']) {
+                    continue;
+                }
+
+                $urlBlacklist = null;
+                if (count($exclusion['urls'])) {
+                    return !preg_match('{('.implode('|', $exclusion['urls']).')}i', $request->getPathInfo());
+                }
+
+                return false;
+            }
+        }
+
+        return $isActivated;
+    }
+}

src/Symfony/Bridge/Monolog/Tests/Handler/FingersCrossed/HttpCodeActivationStrategyTest.php

@@ -0,0 +1,81 @@
+<?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\FingersCrossed;
+
+use Monolog\Logger;
+use PHPUnit\Framework\TestCase;
+use Symfony\Bridge\Monolog\Handler\FingersCrossed\HttpCodeActivationStrategy;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\RequestStack;
+use Symfony\Component\HttpKernel\Exception\HttpException;
+
+class HttpCodeActivationStrategyTest extends TestCase
+{
+    /**
+     * @expectedException \LogicException
+     */
+    public function testExclusionsWithoutCode()
+    {
+        new HttpCodeActivationStrategy(new RequestStack(), array(array('urls' => array())), Logger::WARNING);
+    }
+
+    /**
+     * @expectedException \LogicException
+     */
+    public function testExclusionsWithoutUrls()
+    {
+        new HttpCodeActivationStrategy(new RequestStack(), array(array('code' => 404)), Logger::WARNING);
+    }
+
+    /**
+     * @dataProvider isActivatedProvider
+     */
+    public function testIsActivated($url, $record, $expected)
+    {
+        $requestStack = new RequestStack();
+        $requestStack->push(Request::create($url));
+
+        $strategy = new HttpCodeActivationStrategy(
+            $requestStack,
+            array(
+                array('code' => 403, 'urls' => array()),
+                array('code' => 404, 'urls' => array()),
+                array('code' => 405, 'urls' => array()),
+                array('code' => 400, 'urls' => array('^/400/a', '^/400/b')),
+            ),
+            Logger::WARNING
+        );
+
+        $this->assertEquals($expected, $strategy->isHandlerActivated($record));
+    }
+
+    public function isActivatedProvider()
+    {
+        return array(
+            array('/test',  array('level' => Logger::ERROR), true),
+            array('/400',   array('level' => Logger::ERROR, 'context' => $this->getContextException(400)), true),
+            array('/400/a', array('level' => Logger::ERROR, 'context' => $this->getContextException(400)), false),
+            array('/400/b', array('level' => Logger::ERROR, 'context' => $this->getContextException(400)), false),
+            array('/400/c', array('level' => Logger::ERROR, 'context' => $this->getContextException(400)), true),
+            array('/401',   array('level' => Logger::ERROR, 'context' => $this->getContextException(401)), true),
+            array('/403',   array('level' => Logger::ERROR, 'context' => $this->getContextException(403)), false),
+            array('/404',   array('level' => Logger::ERROR, 'context' => $this->getContextException(404)), false),
+            array('/405',   array('level' => Logger::ERROR, 'context' => $this->getContextException(405)), false),
+            array('/500',   array('level' => Logger::ERROR, 'context' => $this->getContextException(500)), true),
+        );
+    }
+
+    protected function getContextException($code)
+    {
+        return array('exception' => new HttpException($code));
+    }
+}