byethrow
  • English

      • Function: inspect()

      Executes a side effect function on the success 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

      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 inspect: <Result.Result<42, never>, void>(fn: (a: 42) => void) => (result: Result.Result<42, never>) => Result.Result<42, never> (+1 overload)
      inspect      ((
      value: 42
      value      ) => 
      var console: Console
      console      .
      Console.log(...data: any[]): void
      The console.log() static method outputs a message to the console.
      

      MDN Reference
      log      ('Debug:', 
      value: 42
      value      )),      
);
// Console output: "Debug: 42"
// Result: { type: 'Success', value: 42 }

      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 inspect: <Result.Result<never, "error">, void>(fn: (a: never) => void) => (result: Result.Result<never, "error">) => Result.Result<never, "error"> (+1 overload)
      inspect      ((
      value: never
      value      ) => 
      var console: Console
      console      .
      Console.log(...data: any[]): void
      The console.log() static method outputs a message to the console.
      

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

      See

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

      Call Signature

      inspect<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

      inspect<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>>