ts-simple-result

Typescript "Result" types.

Types for handling errors and exceptions in a functional way.

Example usage:

``typescript
import { Result, Ok, Err } from 'ts-simple-result';

function divide(a: number, b: number): Result {
if (b === 0) {
return Err('Cannot divide by zero');
}
return Ok(a / b);
}

const result = divide(10, 2);
if (result.ok) {
console.log('Result is', result.val);
} else {
console.log('Error is', result.val);
}
`

All types used by this library are simple object types (no classes) so they can easily be passed around and serialized -- This library is designed primarily for use in Next.js Server Actions, and to have a simple, stable API.

API

$3

There are two ways to create a result:

`typescript
const yes = Ok(42);
const no = Err('Nope');

// Both of these are valid Result types
const results: Result[] = [yes, no];
`

There is additionally an AsyncResult defined which is the following:

`typescript
export type AsyncResult = Promise>;
`

Using AsyncResult keeps function declarations short.

$3

AsyncResult

Returns a promise that resolves to a Result containing Ok(resolved) or Err(rejected).

`typescript
import { readFile } from 'fs/promises';
import { AsyncResult } from 'ts-simple-result';

// res: Result
const res = await AsyncResult(readFile('./filename.txt'));

if (res.ok) {
console.log('File contents:', res.val);
} else {
// Error object is the result typr
console.log('Error reading file:', res.val.message);
}
`

AsyncResult.all

Similar to Promise.all(...) but returns an AsyncResult, which contains an array of results, or an error if any of the promises fail.

`typescript
import { readFile } from 'fs/promises';
import { AsyncResult, Err, Ok } from 'ts-simple-result';

enum FileErrorCode {
NotFound = 'notfound',
}

async function getFile(path: string): AsyncResult {
const res = await AsyncResult(readFile(path));
if (!res.ok) {
return Err(FileErrorCode.NotFound);
}

return Ok(res.val);
}

const res = await AsyncResult.all([
getFile('./file1.txt'),
getFile('./file2.txt'),
getFile('./file3.txt'),
]);

if (res.ok) {
console.log('array of buffers:', res.val);
} else {
console.log('Error reading file:', res.val);
}
``