krustykrab

Implementation of some helpers of Rust stdlib on JavaScript/TypeScript

Api reference

Implemented helpers

Option

import { Some, None } from "krustykrab";

const someOption = Some("foo");
const noneOption = None();

Rust reference

krustykrab reference

Result

import { Ok, Err } from "krustykrab";

const okResult = Ok("foo");
const errResult = Err("bar");

Rust reference

krustykrab reference

Additional helpers

unwrap

Panics if the value is null or undefined or returns it otherwise

import { unwrap } from "krustykrab";

const fooOrUndefined = document.getElementById('foo'); // html element or `undefined`
const foo = unwrap(fooOrUndefined); // exactly html element

unwrapOr

Returns the value if it's not null or undefined, or returns the default value

import { unwrapOr } from "krustykrab";

const foo: Partial<Record<string, string>> = { bar: 'baz' };

unwrapOr(foo.bar, 'qux'); // returns 'baz'
unwrapOr(foo.bat, 'qux'); // returns 'qux'

unwrapOrElse

Returns the value if it's not null or undefined, or computes it

import { unwrapOrElse } from "krustykrab";

const foo: Partial<Record<string, string>> = { bar: 'baz' };

unwrapOrElse(foo.bar, () => 'qux'); // returns 'baz'
unwrapOrElse(foo.bat, () => 'qux'); // returns 'qux'

getResult

Converts Promise to Result

import { getResult } from "krustykrab";

const successResult = await getResult(Promise.resolve('foo'));
successResult.unwrap(); // returns 'foo'

const errorResult = await getResult(Promise.reject('bar'));
errorResult.unwrapErr(); // returns 'bar'

toOption

Convert a nullable variable to Option

import { toOption } from "krustykrab";

const option = toOption('foo');
option.isNone(); // returns `false`;
option.unwrap(); // returns `'foo'`;

toOption(null).isNone(); // returns `true`
toOption(undefined).isNone(); // returns `true`

tryCatch

Wrap the result of a function call with Result

import { tryCatch } from "krustykrab";

const successResult = tryCatch(() => JSON.parse('{"foo": "bar"}'));
successResult.unwrap(); // returns `{ foo: "bar" }`

const errorResult = tryCatch(() => JSON.parse("{invalid json}"));
errorResult.isErr(); // returns `true`