byethrow
  • English

      • Function: inspectError()

      Executes a side effect function on the error value of a Result or ResultAsync, without modifying the original result. This is useful for debugging, logging, or performing other side effects while maintaining the original value and error state.

      Type Param

      R1

      The input Result or ResultAsync.

      Type Param

      R2

      The return type of the inspection function.

      Examples

      Failure Case

      import { 
      import Result
      Result       } from '@praha/byethrow';      

const 
      const result: Result.Result<never, "error">
      result       = 
      import Result
      Result      .
      const pipe: <Result.Result<never, "error">, Result.Result<never, "error">>(a: Result.Result<never, "error">, ab: (a: Result.Result<never, "error">) => Result.Result<never, "error">) => Result.Result<never, "error"> (+25 overloads)
      pipe      (      
  
      import Result
      Result      .
      const fail: <"error">(error: "error") => Result.Result<never, "error"> (+1 overload)
      fail      ('error'),      
  
      import Result
      Result      .
      const inspectError: <Result.Result<never, "error">, void>(fn: (a: "error") => void) => (result: Result.Result<never, "error">) => Result.Result<never, "error"> (+1 overload)
      inspectError      ((
      error: "error"
      error      ) => 
      var console: Console
      console      .
      Console.log(...data: any[]): void
      The console.log() static method outputs a message to the console.
      

      MDN Reference
      log      ('Debug error:', 
      error: "error"
      error      )),      
);
// Console output: "Debug error: error"
// Result: { type: 'Failure', error: 'error' }

      Success Case

      import { 
      import Result
      Result       } from '@praha/byethrow';      

const 
      const result: Result.Result<42, never>
      result       = 
      import Result
      Result      .
      const pipe: <Result.Result<42, never>, Result.Result<42, never>>(a: Result.Result<42, never>, ab: (a: Result.Result<42, never>) => Result.Result<42, never>) => Result.Result<42, never> (+25 overloads)
      pipe      (      
  
      import Result
      Result      .
      const succeed: <42>(value: 42) => Result.Result<42, never> (+1 overload)
      succeed      (42),      
  
      import Result
      Result      .
      const inspectError: <Result.Result<42, never>, void>(fn: (a: never) => void) => (result: Result.Result<42, never>) => Result.Result<42, never> (+1 overload)
      inspectError      ((
      error: never
      error      ) => 
      var console: Console
      console      .
      Console.log(...data: any[]): void
      The console.log() static method outputs a message to the console.
      

      MDN Reference
      log      ('Debug error:', 
      error: never
      error      )),      
);
// No console output
// Result: { type: 'Success', value: 42 }

      See

      pipe - It is recommended to use this function with the pipe function for better readability and composability.

      Call Signature

      inspectError<R1, R2>(fn): (result) => ResultFor<R1 | R2, InferSuccess<R1>, InferFailure<R1>>

      Type Parameters

      R1

      R1 extends ResultMaybeAsync<any, any>

      R2

      R2

      Parameters

      fn

      (a) => R2

      Returns

      (result) => ResultFor<R1 | R2, InferSuccess<R1>, InferFailure<R1>>

      Call Signature

      inspectError<F>(fn): <R1>(result) => ResultFor<R1 | ReturnType<F>, InferSuccess<R1>, InferFailure<R1>>

      Type Parameters

      F

      F extends (a) => unknown

      Parameters

      fn

      F

      Returns

      <R1>(result) => ResultFor<R1 | ReturnType<F>, InferSuccess<R1>, InferFailure<R1>>