Solution: Compose Decorators Dynamically Based on Configuration

Explore how to implement reusable logging and timing decorators for async functions in Node.js. Learn to dynamically compose these decorators based on configuration without changing the base function, enabling environment-specific instrumentation for development, staging, and production.

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Solution explanation
Revisit the problem statement

Solution explanation

Lines 2–6: We define processOrder, a mock async service that simulates an order-processing delay. It represents our core business logic.
Lines 9–16: We create withLogging(fn) to add visibility:
- Logs the input arguments before execution.
- Waits for the function result.
- Logs the returned output afterward.
- Returns the same result transparently.
Lines 19–27: We define withTiming(fn) to measure performance:
- Records the start time before calling the wrapped function.
- Awaits its completion. ...

1.Introduction to Node.js Patterns

2.Factory Pattern: Generate Config-Driven Services Dynamically

3.Builder Pattern: Assemble Complex Objects with Fluent APIs

4.Decorator Pattern: Extend Behavior Without Modifying Core Logic

5.Adapter Pattern: Standardize Interface Across Dependencies

6.Proxy Pattern: Intercept and Control Access Transparently

7.Strategy Pattern: Swap Algorithms Based on Context

8.Wrapping Up

Solution: Compose Decorators Dynamically Based on Configuration

Solution explanation