throw-utils

One-liner helpers for convenient error throwing.

• Installation
• Usecases
• API
  • throwError(error)
  • throwIf(condition, error)
  • throwAsync(error)
  • toError(value) ⇒ Error
• License

Installation

npm i throw-utils

Usecases

1. Return value or throw error if value is empty:

   const { throwError } = require('throw-utils');
   
   function foo() {
     // ...
    
   - if (result) {
   -   return result;
   - } else {
   -   throw new Error('Empty result');
   - }
    
   + return result || throwError('Empty result');
   }
   

2. Throw error in arrow function one-liner:

   - const fn = () => { throw new Error('foo'); };
   
   + const fn = () => throwError('foo');
   

3. Throw error in conditional one-liner:

   const { throwIf } = require('throw-utils');
   
   function foo(a, b) {
   - if (!a) {
   -   throw new Error('Parameter a is required.');
   - }
   - if (!b) {
   -   throw new Error('Parameter b is required.');
   - }
   
   + throwIf(!a, 'Parameter a is required.');
   + throwIf(!b, 'Parameter b is required.');
   }   
   

4. Throw error in next tick:

   const { throwAsync } = require('throw-utils');
   
   - setTimeout(() => {
   -   throw new Error('foo');
   - }, 0);
   
   + throwAsync('foo');
   

API

throwError(error)

Throws new error. Allows simple usage of throw in expressions and arrow functions.

Kind: global function
Params

• error String | Error

Example

const { throwError } = require('throw-utils');

// usage in expression
const foo = value || throwError('Error');

// usage in arrow function
setTimeout(() => throwError('Error'), 1000);

throwIf(condition, error)

Conditionally throws error. Convenient replacement of if...throw block with one-liner:

Kind: global function
Params

• condition *
• error String | Error | function

Example

const { throwIf } = require('throw-utils');

throwIf(foo > 10, 'my error');
throwIf(foo > 10, new Error('my error'));
throwIf(foo > 10, () => `my error: ${JSON.stringify(data)}`); // lazy calculated Error

throwAsync(error)

Throws error in next event loop tick. Useful to throw error out of promise chain.

Kind: global function
Params

• error String | Error

Example

const { throwAsync } = require('throw-utils');

Promise.resolve()
  .then(...)
  .catch(e => throwAsync(e));

toError(value) ⇒ Error

Converts anything to Error.

Kind: global function
Params

• value String | Error

License

MIT @ Vitaliy Potapov