Package Exports

assert-err

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (assert-err) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

assert-err

assertion library that throws user-specified error types (accepts error class and message)

Installation

npm i --save assert-err

Usage

Example 1: full example

// example-1.js
var assertErr = require('assert-err')

function add (a, b) {
  assertErr(typeof a === 'number', TypeError, '"a" must be a number')
  assertErr(typeof b === 'number', TypeError, '"b" must be a number') //  line 6
  return a + b
}

add(1, 'no') // line 10
/*
TypeError: "b" must be a number
    at add (example-1.js:6:3)
    at Object.<anonymous> (example-1.js:10:1)
    at Module._compile (module.js:413:34)
    at Object.Module._extensions..js (module.js:422:10)
    at Module.load (module.js:357:32)
    at Function.Module._load (module.js:314:12)
    at Function.Module.runMain (module.js:447:10)
    at startup (node.js:139:18)
    at node.js:999:3
*/

Example 2: Error props

If using global.Error, assertErr accepts a props argument to extend error

assertErr(false, Error, 'message', { code: 1, status: 'status' }) // 0 args
// { [Error: boom] code: 1, status: 'status' }

Example 3: args

assertErr supports up to 5 err constructor args

assertErr(false, CustomError) // 0 args
assertErr(false, CustomError, 'foo') // 1 args
assertErr(false, CustomError, 'foo', 'bar') // 2 args
assertErr(false, CustomError, 'foo', 'bar', 'qux') // 3 args
assertErr(false, CustomError, 'foo', 'bar', 'qux', 'corge') // 4 args
assertErr(false, CustomError, 'foo', 'bar', 'qux', 'corge', 'yolo') // 5 args
// error...
assertErr(false, CustomError, 'foo', 'bar', 'qux', 'corge', 'yolo', 'toomany') // 6 args
// Error: assertErr does not support more than five Error args

License

MIT