Laravel Interview Questions & Answers Guide

Debug Laravel file uploads by logging $_FILES, checking $request->hasFile(), validating isValid(), inspecting $_SERVER['CONTENT_LENGTH'] vs post_max_size, and enabling APP_DEBUG=true with detailed exception traces.

Common failures: missing enctype="multipart/form-data", exceeded upload_max_filesize/post_max_size, invalid CSRF, or disk full. Log raw $_FILES array first, verify file presence with hasFile()/isValid(), check server limits in php.ini, and use dump($request->allFiles()) for full inspection. The Browser Network tab reveals payload size issues.

Code

// Controller debug
public function upload(Request $request) {
    \Log::info('FILES', $_FILES); // Raw PHP files
    \Log::info('Request files', $request->allFiles()); // Laravel files
    
    if (!$request->hasFile('file')) {
        return 'No file found';
    }
    
    $file = $request->file('file');
    \Log::info('File valid?', ['valid' => $file->isValid(), 'error' => $file->getError()]);
    \Log::info('File details', [
        'size' => $file->getSize(),
        'mime' => $file->getMimeType(),
        'clientName' => $file->getClientOriginalName()
    ]);
    
    // Test store
    try {
        $path = $file->store('uploads');
        return "Success: $path";
    } catch (Exception $e) {
        \Log::error('Upload failed', ['error' => $e->getMessage()]);
    }
}