@yveskaufmann/retry

retry-utility

Utility for retrying promise based operation on certain situations.

• Provides an imperative API.
• Class decorators to mark async functions to be retryable Supports various backoff strategies: fixed, linear, exponential.

Installation

npm install @yveskaufmann/retry

Usage

The example below demonstrates how to annotate methods to mark them as retryable. When retryWhen return true the method is retried until it reaches the maxRetries limit.

When the retry limit is reached last result is returned or the last error is thrown.

When the limit is reached the last result, or the last thrown

NOTE: The Retryable annotation only works with methods that returning promises like async methods.

class Service {

  @Retryable({
    retryWhen: (result, err) => err != null,
    delay: Retry.Delays.linear(50),
    maxRetries: 3,
  })
  async retryOnAnyError() {
    // ...
  }

  @Retryable({
    retryWhen: (result, err) => err == null && result == false,
    delay: Retry.Delays.linear(50),
    maxRetries: 3,
  })
  async retryWhenFalseIsReturned() {
    return Math.random() < 0.6;
  }
}

This utility can also be used without annotating class methods.

 const response = await Retry.do({
  operation: () => client.get(...),
  retryWhen: (result, err) => HttpError.isTooManyRequest(err)
  maxRetries: 3,
  delay: Retry.Delays.constant(50),
});

API

The API is documented in the provided typescript definition file.