Log Fake Laravel Package

Getting Started

First Steps

1. Installation Add the package via Composer:

   composer require --dev timacdonald/log-fake
   

   Register the service provider in config/app.php (if not auto-discovered):

   'providers' => [
       // ...
       Timacdonald\LogFake\LogFakeServiceProvider::class,
   ],
   

2. Basic Usage Replace Laravel’s default logger with LogFake in your test setup:

   use Timacdonald\LogFake\LogFake;
   
   public function test_logging()
   {
       LogFake::shouldReceive('info')
              ->once()
              ->with('Test message');
   
       Log::info('Test message');
   }
   

3. First Use Case

   • Mocking Log Calls: Replace Log::info(), Log::error(), etc., with LogFake to assert log messages in tests.
   • Verify Logged Data: Check if specific messages, channels, or contexts were logged.

Implementation Patterns

Common Workflows

1. Asserting Logged Messages

   LogFake::assertLogged('Test message'); // Checks if message exists
   LogFake::assertLoggedTimes(1, 'Test message'); // Checks exact count
   

2. Testing Log Channels

   LogFake::shouldReceive('channel->error')
          ->once()
          ->with('Error in channel', ['context' => 'key']);
   
   Log::channel('custom')->error('Error in channel', ['context' => 'key']);
   

3. Resetting Fake Logs

   LogFake::reset(); // Clears all recorded logs between tests
   

4. Testing Log Levels

   LogFake::shouldReceive('emergency')
          ->never(); // Assert no emergency logs were called
   

Integration Tips

• Use with Laravel’s Log Facade: Replace Log with LogFake in tests by binding it in setUp():

  public function setUp(): void
  {
      parent::setUp();
      $this->app->singleton(\Illuminate\Log\LoggerInterface::class, function () {
          return LogFake::make();
      });
  }
  

• Extend for Custom Assertions: Override LogFake to add domain-specific checks:

  LogFake::assertErrorContains('Failed', 'Expected error message');
  

Gotchas and Tips

Pitfalls

1. Forgetting to Reset

   • Issue: Logs accumulate across test methods, causing false positives.
   • Fix: Call LogFake::reset() in tearDown() or at the start of each test.

2. Channel-Specific Mocking

   • Issue: Mocking Log::channel('custom') requires explicit channel binding in LogFake.
   • Fix: Use LogFake::channel('custom')->shouldReceive() for channel-specific assertions.

3. Context/Stack Data

   • Issue: Asserting nested contexts (e.g., ['user' => ['id' => 1]]) requires precise matching.
   • Fix: Use withArgs() or with() for complex context checks:

     LogFake::shouldReceive('info')
            ->once()
            ->withArgs(['Test', ['user' => ['id' => 1]]]);
     

4. Global State in Tests

   • Issue: LogFake is global; shared state can cause test pollution.
   • Fix: Use LogFake::fake() to create isolated instances per test class.

Debugging Tips

• Inspect Logs: Dump recorded logs for debugging:

  dd(LogFake::getLogs());
  

• Verify Mocks: Use shouldReceive() with andReturnSelf() for chained assertions:

  LogFake::shouldReceive('info')
         ->andReturnSelf()
         ->once();
  

Extension Points

1. Custom Log Levels Extend LogFake to support custom levels (e.g., debug, verbose):

   LogFake::shouldReceive('debug')->once();
   Log::debug('Debug message');
   

2. Log Formatting Override LogFake::formatLog() to standardize log output for assertions:

   LogFake::formatLog = fn($level, $message, $context) => "[$level] $message";
   

3. Integration with Testing Libraries Combine with Pest or PHPUnit matchers for fluent assertions:

   expect(LogFake::getLogs())->toHaveCount(1);