Strengthen test coverage and mutation score

tests/LoggerTest.php

@@ -419,6 +419,15 @@ public function testDispatchWithFakeTarget2ThrowExceptionWhenCollect(): void
         $logger->flush(true);
     }
 
+    public function testFlushIntervalZeroDoesNotFlushDuringLog(): void
+    {
+        $this->logger->setFlushInterval(0);
+        $this->target->setExportInterval(1);
+        $this->logger->log(LogLevel::INFO, 'test');
+
+        $this->assertSame(0, $this->target->getExportCount());
+    }
+
     public function testSetTraceLevelWithCustomContextProvider(): void
     {
         $logger = new Logger(contextProvider: new StubContextProvider());

tests/Message/ContextValueExtractorTest.php

@@ -0,0 +1,38 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Yiisoft\Log\Tests\Message;
+
+use PHPUnit\Framework\TestCase;
+use Yiisoft\Log\Message\ContextValueExtractor;
+
+final class ContextValueExtractorTest extends TestCase
+{
+    public static function dataExtract(): array
+    {
+        return [
+            'empty-key-found' => [['' => 'found'], '', [true, 'found']],
+            'empty-key-not-found' => [['foo' => 'bar'], '', [false, null]],
+            'simple-key' => [['foo' => 'bar'], 'foo', [true, 'bar']],
+            'missing-key' => [['foo' => 'bar'], 'baz', [false, null]],
+            'nested-key' => [['user' => ['name' => 'John']], 'user.name', [true, 'John']],
+            'nested-key-not-found' => [['user' => ['name' => 'John']], 'user.age', [false, null]],
+            'nested-key-non-array-intermediate' => [['user' => 'string'], 'user.name', [false, null]],
+            'escaped-dot' => [['user.name' => 'John'], 'user\.name', [true, 'John']],
+            'escaped-backslash' => [['user\\' => 'John'], 'user\\\\', [true, 'John']],
+            'deeply-nested' => [['a' => ['b' => ['c' => 'deep']]], 'a.b.c', [true, 'deep']],
+            'backslash-key-nested' => [['a\\' => ['b' => 'value']], 'a\\\\.b', [true, 'value']],
+            'multiple-backslashes-before-dot' => [['a\\\\' => ['b' => 'value']], 'a\\\\\\\\.b', [true, 'value']],
+            'escaped-dot-and-nesting' => [['a.b' => ['c' => 'value']], 'a\\.b.c', [true, 'value']],
+        ];
+    }
+
+    /**
+     * @dataProvider dataExtract
+     */
+    public function testExtract(array $context, string $key, array $expected): void
+    {
+        $this->assertSame($expected, ContextValueExtractor::extract($context, $key));
+    }
+}

tests/Message/FormatterTest.php

@@ -217,6 +217,44 @@ public function testFormatWithTraceInContext(string $expectedTrace, array $trace
         $this->assertSame($expected, $this->formatter->format($message, []));
     }
 
+    public function testTraceWithFileWithoutLineUsesFunction(): void
+    {
+        $this->formatter->setTimestampFormat('Y-m-d H:i:s');
+        $message = new Message(
+            LogLevel::INFO,
+            'message',
+            [
+                'category' => 'app',
+                'time' => 1_508_160_390,
+                'trace' => [['file' => '/path/to/file', 'function' => 'myFunc']],
+            ],
+        );
+
+        $result = $this->formatter->format($message, []);
+
+        $this->assertStringNotContainsString('in /path/to/file:', $result);
+        $this->assertStringContainsString('myFunc', $result);
+    }
+
+    public function testTraceWithLineWithoutFileUsesFunction(): void
+    {
+        $this->formatter->setTimestampFormat('Y-m-d H:i:s');
+        $message = new Message(
+            LogLevel::INFO,
+            'message',
+            [
+                'category' => 'app',
+                'time' => 1_508_160_390,
+                'trace' => [['line' => 99, 'function' => 'myFunc']],
+            ],
+        );
+
+        $result = $this->formatter->format($message, []);
+
+        $this->assertStringNotContainsString(':99', $result);
+        $this->assertStringContainsString('myFunc', $result);
+    }
+
     public function invalidCallableReturnStringProvider(): array
     {
         return [

tests/MessageTest.php

@@ -192,6 +192,20 @@ public function testCategory(string $expected, array $context): void
         $this->assertSame($expected, $message->category());
     }
 
+    public function testTraceReturnsNullWhenNoTraceInContext(): void
+    {
+        $message = new Message(LogLevel::INFO, 'message', ['foo' => 'bar']);
+
+        $this->assertNull($message->trace());
+    }
+
+    public function testMessageWithoutPlaceholdersReturnsUnchanged(): void
+    {
+        $message = new Message(LogLevel::INFO, 'simple message without braces', ['foo' => 'bar']);
+
+        $this->assertSame('simple message without braces', $message->message());
+    }
+
     public function testInvalidCategoryType(): void
     {
         $message = new Message(LogLevel::INFO, 'message', ['category' => 23.1]);

tests/TargetTest.php

@@ -495,6 +495,54 @@ public function testSetLevelsViaConstructorWithEmptyArray(): void
         $this->assertCount(3, $messages);
     }
 
+    public function testCollectWithNoMessagesDoesNotExport(): void
+    {
+        $this->target->collect([], true);
+
+        $this->assertSame(0, $this->target->getExportCount());
+    }
+
+    public function testExportIntervalZeroDoesNotExport(): void
+    {
+        $this->target->setExportInterval(0);
+        $this->target->collect(
+            [new Message(LogLevel::INFO, 'message', ['category' => 'app'])],
+            false,
+        );
+
+        $this->assertSame(0, $this->target->getExportCount());
+    }
+
+    public function testSetTimestampFormatAffectsNonExportedMessages(): void
+    {
+        $this->target->setTimestampFormat('Y');
+        $this->target->collect(
+            [new Message(LogLevel::INFO, 'message', ['category' => 'app', 'time' => 1_508_160_390])],
+            false,
+        );
+
+        $this->assertStringStartsWith('2017 ', $this->target->formatMessages());
+    }
+
+    public function testFilterContinuesAfterExcludedCategory(): void
+    {
+        $this->target->setExcept(['excluded']);
+        $this->target->collect(
+            [
+                new Message(LogLevel::INFO, 'first', ['category' => 'excluded']),
+                new Message(LogLevel::INFO, 'second', ['category' => 'allowed']),
+                new Message(LogLevel::INFO, 'third', ['category' => 'allowed']),
+            ],
+            false,
+        );
+
+        $messages = $this->target->getMessages();
+
+        $this->assertCount(2, $messages);
+        $this->assertSame('second', $messages[0]->message());
+        $this->assertSame('third', $messages[1]->message());
+    }
+
     private function collectOneAndExport(string $level, string $message, array $context = []): void
     {
         $this->target->collect([new Message($level, $message, $context)], true);