Add the CloudWatchFormatter

Author: mnapoli

.gitignore

@@ -2,3 +2,4 @@
 /composer.phar
 /composer.lock
 /.phpunit.result.cache
+/.phpunit.cache

composer.json

@@ -1,25 +1,26 @@
 {
-    "name": "mnapoli/myproject",
-    "description": "Give it a nice description!",
-    "keywords": [],
+    "name": "bref/monolog-bridge",
+    "description": "Monolog formatter optimized for AWS Lambda and CloudWatch",
+    "keywords": ["bref", "monolog", "aws", "lambda", "cloudwatch"],
     "license": "MIT",
     "type": "library",
     "autoload": {
         "psr-4": {
-            "MyProject\\": "src/"
+            "Bref\\Monolog\\": "src/"
         }
     },
     "autoload-dev": {
         "psr-4": {
-            "MyProject\\Test\\": "tests/"
+            "Bref\\Monolog\\Test\\": "tests/"
         }
     },
     "require": {
-        "php": ">=8.0"
+        "php": ">=8.1",
+        "monolog/monolog": "^3"
     },
     "require-dev": {
-        "phpunit/phpunit": "^9.0",
-        "mnapoli/hard-mode": "^0.3.0",
+        "phpunit/phpunit": "^11",
+        "mnapoli/hard-mode": "^0.3",
         "phpstan/phpstan": "^1"
     },
     "config": {

phpunit.xml

@@ -1,13 +1,13 @@
 <?xml version="1.0" encoding="utf-8"?>
-<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" colors="true" bootstrap="./vendor/autoload.php" xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.3/phpunit.xsd">
-  <coverage processUncoveredFiles="true">
-    <include>
-      <directory suffix=".php">src</directory>
-    </include>
-  </coverage>
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" colors="true" bootstrap="./vendor/autoload.php" xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/11.5/phpunit.xsd" cacheDirectory=".phpunit.cache">
   <testsuites>
     <testsuite name="Test suite">
       <directory>./tests/</directory>
     </testsuite>
   </testsuites>
+  <source>
+    <include>
+      <directory suffix=".php">src</directory>
+    </include>
+  </source>
 </phpunit>

src/.gitkeep

@@ -0,0 +1,115 @@
+<?php declare(strict_types=1);
+
+namespace Bref\Monolog;
+
+use ArrayObject;
+use DateTimeInterface;
+use JsonSerializable;
+use Monolog\Formatter\NormalizerFormatter;
+use Monolog\LogRecord;
+use Stringable;
+use Throwable;
+
+/**
+ * Monolog formatter optimized for CloudWatch logs.
+ */
+class CloudWatchFormatter extends NormalizerFormatter
+{
+    public function format(LogRecord $record): string
+    {
+        $level = strtoupper($record->level->name);
+        // Make sure everything is kept on one line to count as one record
+        $message = str_replace(["\r\n", "\r", "\n"], ' ', $record->message);
+        $json = $this->toJson($this->normalizeRecord($record), true);
+
+        return "$level\t$message\t$json\n";
+    }
+
+    public function formatBatch(array $records): string
+    {
+        return implode('', array_map(fn (LogRecord $record) => $this->format($record), $records));
+    }
+
+    /**
+     * @return array<array|bool|float|int|\stdClass|string|null>
+     */
+    protected function normalizeRecord(LogRecord $record): array
+    {
+        $data = [
+            'message' => $record->message,
+            'level' => strtoupper($record->level->name),
+        ];
+        $context = $record->context;
+        // Move any exception to the root
+        $exception = $context['exception'] ?? null;
+        if ($exception instanceof Throwable) {
+            $data['exception'] = $exception;
+            unset($context['exception']);
+        }
+        if ($context !== []) {
+            $data['context'] = $context;
+        }
+        if ($record->extra !== []) {
+            $data['extra'] = $record->extra;
+        }
+
+        return $this->normalize($data);
+    }
+
+    /**
+     * @return scalar|array<array|scalar|object|null>|object|null
+     */
+    protected function normalize(mixed $data, int $depth = 0): mixed
+    {
+        if ($depth > $this->maxNormalizeDepth) {
+            return 'Over ' . $this->maxNormalizeDepth . ' levels deep, aborting normalization';
+        }
+
+        if (is_array($data)) {
+            $normalized = [];
+
+            $count = 1;
+            foreach ($data as $key => $value) {
+                if ($count++ > $this->maxNormalizeItemCount) {
+                    $normalized['...'] = 'Over ' . $this->maxNormalizeItemCount . ' items (' . count($data) . ' total), aborting normalization';
+                    break;
+                }
+
+                $normalized[$key] = $this->normalize($value, $depth + 1);
+            }
+
+            return $normalized;
+        }
+
+        if (is_object($data)) {
+            if ($data instanceof DateTimeInterface) {
+                return $this->formatDate($data);
+            }
+
+            if ($data instanceof Throwable) {
+                return $this->normalizeException($data, $depth);
+            }
+
+            // if the object has specific json serializability we want to make sure we skip the __toString treatment below
+            if ($data instanceof JsonSerializable) {
+                return $data;
+            }
+
+            if ($data instanceof Stringable) {
+                return $data->__toString();
+            }
+
+            if (get_class($data) === '__PHP_Incomplete_Class') {
+                return new ArrayObject($data);
+            }
+
+            return $data;
+        }
+
+        if (is_resource($data)) {
+            return parent::normalize($data);
+        }
+
+        return $data;
+    }
+}

src/CloudWatchFormatter.php

@@ -0,0 +1,71 @@
+<?php declare(strict_types=1);
+
+namespace Bref\Monolog\Test;
+
+use Bref\Monolog\CloudWatchFormatter;
+use Exception;
+use Monolog\Handler\StreamHandler;
+use Monolog\Logger;
+use PHPUnit\Framework\TestCase;
+
+class CloudWatchFormatterTest extends TestCase
+{
+    private Logger $logger;
+    /** @var resource */
+    private $logs;
+
+    public function setUp(): void
+    {
+        parent::setUp();
+        $this->logger = new Logger('default');
+        $this->logs = fopen('php://memory', 'wb+');
+        $handler = new StreamHandler($this->logs);
+        $handler->setFormatter(new CloudWatchFormatter);
+        $this->logger->pushHandler($handler);
+    }
+
+    public function test simple message(): void
+    {
+        $this->logger->info('Test message');
+
+        $this->assertEquals("INFO\tTest message\t" . json_encode([
+            'message' => 'Test message',
+            'level' => 'INFO',
+        ], JSON_THROW_ON_ERROR) . "\n", $this->getLogs());
+    }
+
+    public function test with context(): void
+    {
+        $this->logger->info('Test message', ['key' => 'value']);
+
+        $this->assertEquals("INFO\tTest message\t" . json_encode([
+            'message' => 'Test message',
+            'level' => 'INFO',
+            'context' => ['key' => 'value'],
+        ], JSON_THROW_ON_ERROR) . "\n", $this->getLogs());
+    }
+
+    public function test multiline message(): void
+    {
+        $this->logger->error("Test\nmessage");
+
+        $this->assertEquals("ERROR\tTest message\t" . json_encode([
+            'message' => "Test\nmessage",
+            'level' => 'ERROR',
+        ], JSON_THROW_ON_ERROR) . "\n", $this->getLogs());
+    }
+
+    public function test with exception(): void
+    {
+        $e = new Exception('Test error');
+        $this->logger->info('Test message', ['exception' => $e]);
+
+        $this->assertStringStartsWith('INFO	Test message	{"message":"Test message","level":"INFO","exception":{"class":"Exception","message":"Test error","code":0,"file":', $this->getLogs());
+    }
+
+    private function getLogs(): string
+    {
+        rewind($this->logs);
+        return stream_get_contents($this->logs);
+    }
+}