ts-results

ts-results is a lightweight Javascript library developed to solve a common problem. It returns an object indicating success or failure of an operation instead of throwing/using exceptions. Inspired by Fluent Results Library for C#

Install

npm install @lgse/ts-results

Usage

Result.ok():

1const result = Result.ok();
2
3// result.isOk() returns true

Result<T>.ok():

1const result = Result<Array<number>>.ok([1, 2, 3]);
2const data = result.data(); // [1,2,3]
3
4// result.IsOk() returns true

Result.ok().withData():

1const result = Result.ok().withData([1, 2, 3]);

Result.ok<T>():

1const typedResult = Result.ok<Array<number>>();
2
3typedResult.withData(['Joe', 'Bill']); // Wrong type, will throw error
4typedResult.withData([1, 2, 3]) // OK

Result.fail():

1const result = Result.fail();
2
3// With Error
4const result2 = Result.fail(new Error('Failed because X'));

Result.failIf():

1const result = Result.failIf(1 + 1 === 2); // Fails with truthy condition
2
3// With Error
4const result2 = Result.failIf(1 + 1 === 2, new Error('Failed because X'));

Result.try():

1const result = Result.try(() => {
2  throw new Error('An error occurred');
3}); // Will fail
4
5// With Optional Error Transformer
6const result2 = Result.try(() => {
7  throw new Error('An error occurred');
8}, (e: Error) => new CustomError('...'));

Result.hasErrors():

1  const error = new Error();
2  const result = Result.fail(error);
3  
4  result.hasError(); // true

Result.hasErrorType():

1  class CustomError extends Error {}
2
3  const error = new CustomError();
4  const result = Result.fail(error);
5
6  result.hasErrorType(CustomError); // true