@geersch/nestjs-retry

Description

A NestJS interceptor to easily apply the retry utility function of the @geersch/retry package to an endpoint.

Installation

$ yarn add @geersch/nestjs-retry

Usage

Use the @UseInterceptors decorator imported from the @nestjs/common package to set up the interceptor. The interceptor can be controller-scoped, method-scoped, or global-scoped. Please refer to the NestJS documentation for all the options on how to bind interceptors.

@UseInterceptors(RetryInterceptor)
export class CatsController {}

Using the above notation, each route handler defined in CatsController will use the RetryInterceptor, which uses the EqualJitterBackoffStrategy backoff strategy by default. Alternatively, you can instantiate the RetryInterceptor yourself and pass the desired type of backoff strategy.

@UseInterceptors(new RetryInterceptor(FullJitterBackOffStrategy))
export class CatsController {}

Instead of passing the type of the backoff strategy you can also instantiate it and override its default base delay.

@UseInterceptors(
  new RetryInterceptor(
    new EqualJitterBackoffStrategy({
      baseDelay: 100,
    }),
  ),
)
export class CatsController {}

You can also specify the RetryOptions supported by the retry utility function.

class UnrecoverableError extends Error {}

@UseInterceptors(
  new RetryInterceptor(
    new EqualJitterBackoffStrategy({
      baseDelay: 100,
    }),
    {
      maxDelay: 5000,
      maxRetries: 3,
      scaleFactor: 2,
      abortRetry: (err: any, retryCount: number) => true,
      unrecoverableErrors: [UnrecoverableError],
    },
  ),
)
export class CatsController {}

The interceptor adds the x-attempt header to each retry, which contains the current attempt.

@Controller('cats')
class CatsController {
  @Get()
  @UseInterceptors(new RetryInterceptor(FixedBackoffStrategy))
  findAll(@Headers('x-attempt') header: number): string {
    return 'all the cats';
  }
}

For more information about the retry utility function consults the README of the @geersch/retry package.

License

This package is MIT licensed.