[8.x] Add context to subsequent logs. (#37847)

* Add context to future logs.
- Update Logger.php to store context in state
- Add test to ensure it works properly

* formatting

Co-authored-by: Taylor Otwell <[email protected]>

src/Illuminate/Log/Logger.php

@@ -26,6 +26,13 @@ class Logger implements LoggerInterface
      */
     protected $dispatcher;
 
+    /**
+     * Any context to be added to logs.
+     *
+     * @var array
+     */
+    protected $context = [];
+
     /**
      * Create a new log writer instance.
      *
@@ -171,11 +178,39 @@ public function write($level, $message, array $context = [])
      */
     protected function writeLog($level, $message, $context)
     {
-        $this->logger->{$level}($message = $this->formatMessage($message), $context);
+        $this->logger->{$level}(
+            $message = $this->formatMessage($message),
+            $context = array_merge($this->context, $context)
+        );
 
         $this->fireLogEvent($level, $message, $context);
     }
 
+    /**
+     * Add context to all future logs.
+     *
+     * @param  array  $context
+     * @return $this
+     */
+    public function withContext(array $context = [])
+    {
+        $this->context = array_merge($this->context, $context);
+
+        return $this;
+    }
+
+    /**
+     * Flush the existing context array.
+     *
+     * @return $this
+     */
+    public function withoutContext()
+    {
+        $this->context = [];
+
+        return $this;
+    }
+
     /**
      * Register a new callback handler for when a log event is triggered.
      *

tests/Log/LogLoggerTest.php

@@ -26,6 +26,16 @@ public function testMethodsPassErrorAdditionsToMonolog()
         $writer->error('foo');
     }
 
+    public function testContextIsAddedToAllSubsequentLogs()
+    {
+        $writer = new Logger($monolog = m::mock(Monolog::class));
+        $writer->withContext(['bar' => 'baz']);
+
+        $monolog->shouldReceive('error')->once()->with('foo', ['bar' => 'baz']);
+
+        $writer->error('foo');
+    }
+
     public function testLoggerFiresEventsDispatcher()
     {
         $writer = new Logger($monolog = m::mock(Monolog::class), $events = new Dispatcher);