safe-access-check

0.0.15 • Public • Published

safe-access-check

Build Status NPM version Dependency Status npm

⚠️ Experimental. Intended to be used by compilers and code checkers ⚠️

Todos

  • Existential check of enumerable properties
  • Optional logging of values recieved
  • Clearer, more consistent error messages

Installation

npm install --save-dev safe-access-check

Usage

import { safeCoerce, safePropertyAccess } from 'safe-access-check';
 
// ------------------------------------------------
// 1. Usage as an expression
// ------------------------------------------------
let some = moo + '10' // 'moo10'
some = safeCoerce('moo', '+', 10) // 'moo10'
 
// ------------------------------------------------
// 2. Usage for coercion safeguard
// ------------------------------------------------
[] + {} // "[object Object]"
 
safeCoerce([], '+', {})
// TypeError: 'Unexpected coercion of type "Object" and
// type "Array" using "+" operator'
 
NaN + undefined // NaN
 
safeCoerce(NaN, '+', undefined);
// TypeError: Unexpected coercion of type "NaN" and type
// "undefined" using "+" operator
 
safeCoerce(new String('12'), '>', 12);
// TypeError: Unexpected comparison of type "String" and type
// "number" using ">" operator
 
// ------------------------------------------------
// 3. Usage for better undefined propagation errors
// ------------------------------------------------
const obj = {
  foo: {
    bar: {
      baz: false
    }
  }
}
 
obj.foo.bar._MOO_.baz;
// TypeError: 'Cannot read property 'baz' of undefined'
 
safePropertyAccess(['foo', 'bar', '_MOO_', 'baz'], obj);
// TypeError: Property "_MOO_" does not exist in "Object.foo._MOO_"
 
// ------------------------------------------------
// 4. Usage as out of bounds check
// ------------------------------------------------
const obj = {
  woo: ['']
}
 
obj.woo[1] // undefined
 
safePropertyAccess(['woo', 1], obj)
// TypeError: '"woo[1]" is out of bounds'

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Install

npm i safe-access-check

Weekly Downloads

1

Version

0.0.15

License

MIT

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Collaborators

  • amilajack