byethrow
  • 日本語

      • no-negated-type-guards

      Result.isSuccess() または Result.isFailure() に否定演算子（!）を使用することを禁止します。

      ルールの詳細

      !Result.isSuccess(result) は Result.isFailure(result) と同等ですが、否定形は可読性が低く、読み手に余分な認知負荷をかけます。このルールは自動修正に対応しています。

      誤り

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

const 
      const result: Result.Result<string, Error>
      result      : 
      import Result
      Result      .
      type Result<T, E> = Result.Success<T> | Result.Failure<E>
      A union type representing either a success or a failure.
      @typeParamT  - The type of the Success value.@typeParamE  - The type of the Failure value.@example
      import { Result } from '@praha/byethrow';

const doSomething = (): Result.Result<number, string> => {
  return Math.random() > 0.5
    ? { type: 'Success', value: 10 }
    : { type: 'Failure', error: 'Oops' };
};
      @categoryCore  Types
      Result      <string, Error> = 
      import Result
      Result      .
      const succeed: <"hello">(value: "hello") => Result.Result<"hello", never> (+1 overload)
      succeed      ('hello');      

// ❌ isSuccessを否定
if (!
      import Result
      Result      .
      const isSuccess: <Result.Result<string, Error>>(result: Result.Result<string, Error>) => result is Result.Success<string>
      Type guard to check if a
Result
is a
Success 
.
      @function@typeParamR  - The type of the result to check.@paramresult  - The Result to check.@returnstrue if the result is a Success , otherwise false.@example
      import { Result } from '@praha/byethrow';

const result: Result.Result<number, string> = { type: 'Success', value: 10 };
if (Result.isSuccess(result)) {
  console.log(result.value); // Safe access to value
}
      @categoryType  Guards
      isSuccess      (
      const result: Result.Result<string, Error>
      result      )) {      
  // 失敗時の処理
}

// ❌ isFailureを否定
if (!
      import Result
      Result      .
      const isFailure: <Result.Result<string, Error>>(result: Result.Result<string, Error>) => result is Result.Failure<Error>
      Type guard to check if a
Result
is a
Failure 
.
      @function@typeParamR  - The type of the result to check.@paramresult  - The Result to check.@returnstrue if the result is a Failure , otherwise false.@example
      import { Result } from '@praha/byethrow';

const result: Result.Result<number, string> = { type: 'Failure', error: 'Something went wrong' };
if (Result.isFailure(result)) {
  console.error(result.error); // Safe access to error
}
      @categoryType  Guards
      isFailure      (
      const result: Result.Result<string, Error>
      result      )) {      
  // 成功時の処理
}

      正しい

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

const 
      const result: Result.Result<string, Error>
      result      : 
      import Result
      Result      .
      type Result<T, E> = Result.Success<T> | Result.Failure<E>
      A union type representing either a success or a failure.
      @typeParamT  - The type of the Success value.@typeParamE  - The type of the Failure value.@example
      import { Result } from '@praha/byethrow';

const doSomething = (): Result.Result<number, string> => {
  return Math.random() > 0.5
    ? { type: 'Success', value: 10 }
    : { type: 'Failure', error: 'Oops' };
};
      @categoryCore  Types
      Result      <string, Error> = 
      import Result
      Result      .
      const succeed: <"hello">(value: "hello") => Result.Result<"hello", never> (+1 overload)
      succeed      ('hello');      

// ✅ 直接の型ガードを使用
if (
      import Result
      Result      .
      const isFailure: <Result.Result<string, Error>>(result: Result.Result<string, Error>) => result is Result.Failure<Error>
      Type guard to check if a
Result
is a
Failure 
.
      @function@typeParamR  - The type of the result to check.@paramresult  - The Result to check.@returnstrue if the result is a Failure , otherwise false.@example
      import { Result } from '@praha/byethrow';

const result: Result.Result<number, string> = { type: 'Failure', error: 'Something went wrong' };
if (Result.isFailure(result)) {
  console.error(result.error); // Safe access to error
}
      @categoryType  Guards
      isFailure      (
      const result: Result.Result<string, Error>
      result      )) {      
  // 失敗時の処理
}

if (
      import Result
      Result      .
      const isSuccess: <Result.Result<string, Error>>(result: Result.Result<string, Error>) => result is Result.Success<string>
      Type guard to check if a
Result
is a
Success 
.
      @function@typeParamR  - The type of the result to check.@paramresult  - The Result to check.@returnstrue if the result is a Success , otherwise false.@example
      import { Result } from '@praha/byethrow';

const result: Result.Result<number, string> = { type: 'Success', value: 10 };
if (Result.isSuccess(result)) {
  console.log(result.value); // Safe access to value
}
      @categoryType  Guards
      isSuccess      (
      const result: Result.Result<string, Error>
      result      )) {      
  // 成功時の処理
}