Error Handling & Debugging Interview Questions

Swift error handling includes: 1) try-catch blocks for throwing functions, 2) Result type for functional error handling, 3) Optional chaining for nil handling, 4) Guard statements for early exits, 5) Assertions for debugging, 6) Error protocol for custom errors, 7) Fatal errors for unrecoverable situations, 8) Optional try (try?) for converting errors to nil.

Custom Error implementation includes: 1) Conforming to Error protocol, 2) Defining error cases with enums, 3) Adding associated values for context, 4) Implementing LocalizedError for messages, 5) Adding custom properties for details, 6) Creating error hierarchies, 7) Handling different error cases, 8) Providing recovery suggestions.

Xcode debugging tools include: 1) LLDB debugger commands, 2) Breakpoints with conditions, 3) Variable inspection and watchpoints, 4) Memory graph debugger, 5) Thread navigator, 6) Console logging, 7) View debugger for UI, 8) Network request debugger.

Async error handling involves: 1) Using async throws functions, 2) Implementing Task error handling, 3) Managing actor isolation errors, 4) Handling concurrent errors, 5) Propagating errors in async sequences, 6) Using async variants of try, 7) Implementing error recovery, 8) Proper cancellation handling.

Key differences include: 1) fatalError always terminates, used for unimplemented code, 2) assert only runs in debug builds, 3) precondition runs in debug and -O builds, 4) assert can be disabled, 5) Different message handling, 6) Performance implications, 7) Usage in production code, 8) Integration with debugger.

Result type implementation: 1) Define success/failure cases, 2) Map and flatMap operations, 3) Error type constraints, 4) Converting to throws, 5) Handling async results, 6) Chaining operations, 7) Pattern matching on results, 8) Implementing custom transforms.

Logging best practices: 1) Using OSLog for system integration, 2) Implementing log levels, 3) Structured logging format, 4) Performance considerations, 5) Sensitive data handling, 6) Log rotation and storage, 7) Remote logging setup, 8) Debug vs release logging.

Memory debugging includes: 1) Using Instruments for leaks, 2) Memory graph debugger usage, 3) Heap debugging tools, 4) Reference cycle detection, 5) Allocation tracking, 6) Virtual memory analysis, 7) Memory pressure testing, 8) Debugging retain cycles.

Error propagation patterns: 1) Using rethrows keyword, 2) Error transformation, 3) Error aggregation, 4) Hierarchical error handling, 5) Context preservation, 6) Chain of responsibility, 7) Middleware error handling, 8) Error recovery strategies.

Debug-only implementation: 1) Using #if DEBUG directive, 2) Debug-only extensions, 3) Conditional compilation, 4) Debug logging setup, 5) Development-time features, 6) Performance impact handling, 7) Debug-only assertions, 8) Testing integrations.

Error recovery strategies: 1) Retry mechanisms, 2) Fallback values, 3) Graceful degradation, 4) State restoration, 5) User feedback, 6) Automatic recovery, 7) Recovery suggestions, 8) Cleanup operations.

Network debugging includes: 1) Charles Proxy integration, 2) URLSession debugging, 3) Network Link Conditioner, 4) Request/response logging, 5) Error pattern analysis, 6) Timeout handling, 7) Connection monitoring, 8) SSL/TLS debugging.

Crash reporting techniques: 1) Symbolication process, 2) Crash log analysis, 3) Exception handling, 4) Stack trace collection, 5) Debug information format, 6) Third-party integration, 7) User data collection, 8) Privacy considerations.

Validation error handling: 1) Custom validation rules, 2) Error aggregation, 3) Field-level errors, 4) Error message localization, 5) UI feedback integration, 6) Chain validation, 7) Cross-field validation, 8) Async validation.

SwiftUI debugging includes: 1) Preview debugging, 2) View hierarchy inspection, 3) State monitoring, 4) Layout debugging, 5) Performance profiling, 6) Animation debugging, 7) Environment value tracking, 8) View modifier debugging.

Protocol error handling: 1) Error type constraints, 2) Protocol error requirements, 3) Default implementations, 4) Generic error handling, 5) Error protocol composition, 6) Associated error types, 7) Error transformation, 8) Protocol extension error handling.

Error localization practices: 1) LocalizedError implementation, 2) String catalog usage, 3) Error message templates, 4) Dynamic variable substitution, 5) Pluralization handling, 6) Region-specific messages, 7) Fallback messages, 8) Format specifiers.

Performance debugging: 1) Time Profiler usage, 2) Instruments analysis, 3) Energy logging, 4) Memory allocation tracking, 5) Thread performance, 6) Core Animation debugging, 7) CPU usage analysis, 8) I/O monitoring.

Async error patterns: 1) Task error handling, 2) Actor isolation errors, 3) Structured concurrency errors, 4) Continuation errors, 5) AsyncSequence errors, 6) Task cancellation, 7) Error propagation, 8) Recovery strategies.

Error middleware: 1) Error interception, 2) Error transformation chain, 3) Logging middleware, 4) Recovery middleware, 5) Analytics integration, 6) Error filtering, 7) Context enrichment, 8) Error aggregation.

Database debugging: 1) SQLite debugging tools, 2) Core Data debugging, 3) Migration debugging, 4) Query optimization, 5) Schema validation, 6) Persistence error handling, 7) Data consistency checks, 8) Transaction debugging.

DI error handling: 1) Resolution errors, 2) Circular dependency detection, 3) Optional dependency handling, 4) Lifecycle errors, 5) Configuration validation, 6) Scope errors, 7) Factory errors, 8) Registration errors.

Memory leak debugging: 1) Instruments leaks tool, 2) Memory graph debugger, 3) Allocation tracking, 4) Retain cycle detection, 5) Heap analysis, 6) Object lifecycle tracking, 7) Autorelease pool debugging, 8) Reference counting analysis.

Error boundary patterns: 1) Error containment, 2) Fallback UI, 3) Error recovery UI, 4) State preservation, 5) Error isolation, 6) Component reset, 7) Error reporting, 8) User feedback mechanisms.

Error testing practices: 1) Error case coverage, 2) Recovery testing, 3) Async error testing, 4) Mock error injection, 5) Error propagation tests, 6) UI error testing, 7) Performance impact testing, 8) Integration testing.

Swift error handling includes: 1) try-catch blocks for throwing functions, 2) Result type for functional error handling, 3) Optional chaining for nil handling, 4) Guard statements for early exits, 5) Assertions for debugging, 6) Error protocol for custom errors, 7) Fatal errors for unrecoverable situations, 8) Optional try (try?) for converting errors to nil.

Custom Error implementation includes: 1) Conforming to Error protocol, 2) Defining error cases with enums, 3) Adding associated values for context, 4) Implementing LocalizedError for messages, 5) Adding custom properties for details, 6) Creating error hierarchies, 7) Handling different error cases, 8) Providing recovery suggestions.

Xcode debugging tools include: 1) LLDB debugger commands, 2) Breakpoints with conditions, 3) Variable inspection and watchpoints, 4) Memory graph debugger, 5) Thread navigator, 6) Console logging, 7) View debugger for UI, 8) Network request debugger.

Async error handling involves: 1) Using async throws functions, 2) Implementing Task error handling, 3) Managing actor isolation errors, 4) Handling concurrent errors, 5) Propagating errors in async sequences, 6) Using async variants of try, 7) Implementing error recovery, 8) Proper cancellation handling.

Key differences include: 1) fatalError always terminates, used for unimplemented code, 2) assert only runs in debug builds, 3) precondition runs in debug and -O builds, 4) assert can be disabled, 5) Different message handling, 6) Performance implications, 7) Usage in production code, 8) Integration with debugger.

Result type implementation: 1) Define success/failure cases, 2) Map and flatMap operations, 3) Error type constraints, 4) Converting to throws, 5) Handling async results, 6) Chaining operations, 7) Pattern matching on results, 8) Implementing custom transforms.

Logging best practices: 1) Using OSLog for system integration, 2) Implementing log levels, 3) Structured logging format, 4) Performance considerations, 5) Sensitive data handling, 6) Log rotation and storage, 7) Remote logging setup, 8) Debug vs release logging.

Memory debugging includes: 1) Using Instruments for leaks, 2) Memory graph debugger usage, 3) Heap debugging tools, 4) Reference cycle detection, 5) Allocation tracking, 6) Virtual memory analysis, 7) Memory pressure testing, 8) Debugging retain cycles.

Error propagation patterns: 1) Using rethrows keyword, 2) Error transformation, 3) Error aggregation, 4) Hierarchical error handling, 5) Context preservation, 6) Chain of responsibility, 7) Middleware error handling, 8) Error recovery strategies.

Debug-only implementation: 1) Using #if DEBUG directive, 2) Debug-only extensions, 3) Conditional compilation, 4) Debug logging setup, 5) Development-time features, 6) Performance impact handling, 7) Debug-only assertions, 8) Testing integrations.

Error recovery strategies: 1) Retry mechanisms, 2) Fallback values, 3) Graceful degradation, 4) State restoration, 5) User feedback, 6) Automatic recovery, 7) Recovery suggestions, 8) Cleanup operations.

Network debugging includes: 1) Charles Proxy integration, 2) URLSession debugging, 3) Network Link Conditioner, 4) Request/response logging, 5) Error pattern analysis, 6) Timeout handling, 7) Connection monitoring, 8) SSL/TLS debugging.

Crash reporting techniques: 1) Symbolication process, 2) Crash log analysis, 3) Exception handling, 4) Stack trace collection, 5) Debug information format, 6) Third-party integration, 7) User data collection, 8) Privacy considerations.

Validation error handling: 1) Custom validation rules, 2) Error aggregation, 3) Field-level errors, 4) Error message localization, 5) UI feedback integration, 6) Chain validation, 7) Cross-field validation, 8) Async validation.

SwiftUI debugging includes: 1) Preview debugging, 2) View hierarchy inspection, 3) State monitoring, 4) Layout debugging, 5) Performance profiling, 6) Animation debugging, 7) Environment value tracking, 8) View modifier debugging.

Protocol error handling: 1) Error type constraints, 2) Protocol error requirements, 3) Default implementations, 4) Generic error handling, 5) Error protocol composition, 6) Associated error types, 7) Error transformation, 8) Protocol extension error handling.

Error localization practices: 1) LocalizedError implementation, 2) String catalog usage, 3) Error message templates, 4) Dynamic variable substitution, 5) Pluralization handling, 6) Region-specific messages, 7) Fallback messages, 8) Format specifiers.

Performance debugging: 1) Time Profiler usage, 2) Instruments analysis, 3) Energy logging, 4) Memory allocation tracking, 5) Thread performance, 6) Core Animation debugging, 7) CPU usage analysis, 8) I/O monitoring.

Async error patterns: 1) Task error handling, 2) Actor isolation errors, 3) Structured concurrency errors, 4) Continuation errors, 5) AsyncSequence errors, 6) Task cancellation, 7) Error propagation, 8) Recovery strategies.

Error middleware: 1) Error interception, 2) Error transformation chain, 3) Logging middleware, 4) Recovery middleware, 5) Analytics integration, 6) Error filtering, 7) Context enrichment, 8) Error aggregation.

Database debugging: 1) SQLite debugging tools, 2) Core Data debugging, 3) Migration debugging, 4) Query optimization, 5) Schema validation, 6) Persistence error handling, 7) Data consistency checks, 8) Transaction debugging.

DI error handling: 1) Resolution errors, 2) Circular dependency detection, 3) Optional dependency handling, 4) Lifecycle errors, 5) Configuration validation, 6) Scope errors, 7) Factory errors, 8) Registration errors.

Memory leak debugging: 1) Instruments leaks tool, 2) Memory graph debugger, 3) Allocation tracking, 4) Retain cycle detection, 5) Heap analysis, 6) Object lifecycle tracking, 7) Autorelease pool debugging, 8) Reference counting analysis.

Error boundary patterns: 1) Error containment, 2) Fallback UI, 3) Error recovery UI, 4) State preservation, 5) Error isolation, 6) Component reset, 7) Error reporting, 8) User feedback mechanisms.

Error testing practices: 1) Error case coverage, 2) Recovery testing, 3) Async error testing, 4) Mock error injection, 5) Error propagation tests, 6) UI error testing, 7) Performance impact testing, 8) Integration testing.