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Solution: Retry Failed Requests with Custom Policies

Explore how to apply the Strategy Pattern in Node.js to implement flexible retry mechanisms for failed requests. Learn to create and swap retry policies like No Retry, Fixed Delay, and Exponential Backoff to handle different network failure scenarios dynamically.

Solution explanation

  • Lines 2–11: Define utility helpers:

    • delay(ms) simulates waiting between retries.

    • unstableRequest() randomly succeeds or fails, modeling unreliable network behavior.

  • Lines 14–29: The RequestService class is the context.

    • It delegates all retry behavior to the injected strategy’s .execute() method.

    • On success, logs the final result.

    • On repeated failure, logs a consistent “failed after all retries” message. ...