fix: debug toolbar logs collector behavior on isEmpty()

system/Debug/Toolbar/Collectors/Logs.php

@@ -47,7 +47,7 @@ class Logs extends BaseCollector
      *
      * @var list<array{level: string, msg: string}>
      */
-    protected $data;
+    protected $data = [];
 
     /**
      * Returns the data of this collector to be formatted in the toolbar.
@@ -68,7 +68,7 @@ public function isEmpty(): bool
     {
         $this->collectLogs();
 
-        return $this->data !== [];
+        return $this->data === [];
     }
 
     /**

tests/system/Debug/Toolbar/Collectors/LogsTest.php

@@ -0,0 +1,71 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * This file is part of CodeIgniter 4 framework.
+ *
+ * (c) CodeIgniter Foundation <[email protected]>
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ */
+
+namespace CodeIgniter\Debug\Toolbar\Collectors;
+
+use CodeIgniter\Log\Logger;
+use CodeIgniter\Test\CIUnitTestCase;
+use Config\Logger as LoggerConfig;
+use Config\Services;
+use PHPUnit\Framework\Attributes\Group;
+
+/**
+ * @internal
+ */
+#[Group('Others')]
+final class LogsTest extends CIUnitTestCase
+{
+    private Logger $logger;
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+
+        // The logs collector relies on the logger being in debug mode
+        // so it would populate logCache.
+        $this->logger = new Logger(new LoggerConfig(), debug: true);
+        Services::injectMock('logger', $this->logger);
+    }
+
+    public function testDisplay(): void
+    {
+        // log_message() always creates a new TestLogger instance while
+        // testing, so we need to log directly to our instance.
+        $this->logger->error('Test error');
+        $this->logger->info('Test info');
+
+        $collector = new Logs();
+        $result    = $collector->display();
+
+        $this->assertArrayHasKey('logs', $result);
+        $this->assertCount(2, $result['logs']);
+        $this->assertSame('error', $result['logs'][0]['level']);
+        $this->assertSame('Test error', $result['logs'][0]['msg']);
+        $this->assertSame('info', $result['logs'][1]['level']);
+        $this->assertSame('Test info', $result['logs'][1]['msg']);
+    }
+
+    public function testEmpty(): void
+    {
+        $collector = new Logs();
+        $this->assertTrue($collector->isEmpty());
+    }
+
+    public function testNotEmpty(): void
+    {
+        $this->logger->warning('Test warning');
+
+        $collector = new Logs();
+        $this->assertFalse($collector->isEmpty());
+    }
+}