Artisan Commands & Custom Commands Interview Questions

Artisan is Laravel's command-line interface that provides helpful commands for development. It's accessed using 'php artisan' and includes commands for database migrations, cache clearing, job processing, and other common tasks.

Basic Artisan commands include: 'php artisan list' to show all commands, 'php artisan help' for command details, 'php artisan serve' to start development server, 'php artisan tinker' for REPL, and 'php artisan make' for generating files.

Custom commands are created using 'php artisan make:command CommandName'. This generates a command class in app/Console/Commands. Define command signature and description, implement handle() method for command logic.

Command signature defines command name and arguments/options. Format: 'name:command {argument} {--option}'. Required arguments in curly braces, optional in square brackets. Options prefixed with --.

Custom commands are registered in app/Console/Kernel.php in the commands property or commands() method. They can also be registered using $this->load() method to auto-register all commands in a directory.

Arguments are required input values, options are optional flags. Define using {argument} and {--option}. Access using $this->argument() and $this->option() in handle() method. Can have default values.

Use methods like line(), info(), comment(), question(), error() for different colored output. table() for tabular data, progressBar() for progress indicators. All methods available through Command class.

Command scheduling allows automated command execution at specified intervals. Defined in app/Console/Kernel.php schedule() method. Uses cron expressions or fluent interface. Requires cron entry for schedule:run.

Use Artisan facade: Artisan::call('command:name', ['argument' => 'value']). Can queue commands using Artisan::queue(). Get command output using Artisan::output().

Command isolation ensures each command runs independently. Use separate service providers, handle dependencies properly. Important for testing and avoiding side effects between commands.

Interactive commands use ask(), secret(), confirm() methods. Handle user input validation, provide choices using choice() method. Support default values and validation callbacks.

Use constructor injection or method injection in handle(). Laravel container automatically resolves dependencies. Can bind interfaces to implementations in service providers.

Command hooks run before/after command execution. Define in base command class. Use for setup/cleanup tasks. Support global hooks for all commands. Handle error cases.

Use try-catch blocks, report errors using error() method. Set command exit codes. Handle graceful failures. Support retry logic. Implement proper cleanup on failure.

Validate arguments/options in handle() method. Use custom validation rules. Support interactive validation. Handle validation failures gracefully. Provide helpful error messages.

Use Artisan::call() in tests. Assert command output and behavior. Mock dependencies. Test different argument combinations. Verify side effects.

Group related commands using namespaces. Define command hierarchy. Support sub-commands. Register command groups in console kernel. Handle group-level options.

Dispatch events before/after command execution. Listen for command events. Handle command lifecycle. Support event-driven command execution. Implement event listeners.

Prevent concurrent command execution using mutexes. Implement locking mechanism. Handle timeout scenarios. Support distributed locks. Release locks properly.

Queue long-running commands using queue:work. Handle command queuing logic. Support job dispatching. Implement queue priorities. Handle failed queued commands.

Create custom command middleware. Handle pre/post command execution. Implement middleware pipeline. Support middleware parameters. Register middleware globally or per command.

Cache command results and configuration. Handle cache invalidation. Support cache tags. Implement cache drivers. Handle distributed caching scenarios.

Create pluggable command system. Support command discovery. Handle plugin registration. Implement plugin hooks. Support plugin configuration.

Version commands for backwards compatibility. Handle version negotiation. Support multiple command versions. Implement version deprecation. Handle version migration.

Monitor command execution and performance. Track command usage. Implement logging and metrics. Support alerting. Handle monitoring in distributed systems.

Implement rollback functionality for commands. Handle transaction-like behavior. Support partial rollbacks. Implement cleanup on failure. Handle distributed rollbacks.

Create custom generators for scaffolding. Handle template parsing. Support stub customization. Implement file generation logic. Handle naming conventions.

Generate command documentation automatically. Support markdown generation. Implement help text formatting. Handle multilingual documentation. Support interactive help.

Chain multiple commands in pipeline. Handle data passing between commands. Support conditional execution. Implement pipeline recovery. Handle pipeline monitoring.

Implement command-level authorization. Handle user permissions. Support role-based access. Implement policy checks. Handle authorization failures.