It'd be nice to have this JoinPoint given by the library. Currently it's possible to d

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[Feature Request] Add @afterException joinPoint about kaop-ts HOT 2 CLOSED

k1r0s commented on May 30, 2024

[Feature Request] Add @afterException joinPoint

from kaop-ts.

Comments (2)

k1r0s commented on May 30, 2024

Hi @alexjoverm, thanks for the idea.

This library focus on provide flat options to build more complex stuff.

Now, if you want to handle exceptions in decorated method you can place onException advice to be invoked before main method and you should prevent main method execution using this.stop. You want prevent main method to be invoked because you don't want execute twice.

 // advice will wrap the method to be executed on try, catch block
@beforeMethod(Whatever.OnException) 
myMethod(){  // <- it will not be executed it self
...
}

So, as you suggested, the method is wrapped with try, catch.

  this.stop()
  try {
    meta.result = meta.rawMethod.apply(meta.scope, meta.args)
  } catch (err) {
    // stuff
  }

I'll try to give a standard solution. Anyway this is an example to handle exceptions on decorated method:

https://github.com/k1r0s/kaop-ts/blob/master/test/demos/onExceptionAdvice.spec.ts

from kaop-ts.

k1r0s commented on May 30, 2024

This is what implementation would look like

This feature should pass this test:

import { AdvicePool, IMetadata, onException, adviceMetadata } from "../../src/kaop-ts"

class MyAdvicePool extends AdvicePool {
  static handleError (@adviceMetadata meta: IMetadata) {
    console.log(`There was an error in ${meta.propertyKey}(): -> ${meta.err.message}`)
  }
}

class ExceptionTest {

  @onException(MyAdvicePool.handleError)
  // static wrongMethod (callback: number | Function) {
  static wrongMethod (callback: any) {
    callback()
  }
}

describe("kaop-ts demo -> exception join point", () => {
  it("advice should be executed when decorated method throws an exception", (done) => {
    ExceptionTest.wrongMethod(2)
    ExceptionTest.wrongMethod(done)
  })
})