# isNonConfigurablePropertyIn
> Test if an object's own or inherited property is non-configurable.
## Usage
```javascript
var isNonConfigurablePropertyIn = require( '@stdlib/assert/is-nonconfigurable-property-in' );
```
#### isNonConfigurablePropertyIn( value, property )
Returns a `boolean` indicating if a `value` has a non-configurable `property` (i.e., a property which cannot be deleted and whose descriptor cannot be changed).
```javascript
var defineProperty = require( '@stdlib/utils/define-property' );
var bool;
var obj;
function Foo() {
this.foo = 'bar';
return this;
}
defineProperty( Foo.prototype, 'beep', {
'configurable': true,
'enumerable': true,
'writable': true,
'value': true
});
defineProperty( Foo.prototype, 'boop', {
'configurable': false,
'enumerable': true,
'writable': true,
'value': true
});
obj = new Foo();
bool = isNonConfigurablePropertyIn( obj, 'foo' );
// returns false
bool = isNonConfigurablePropertyIn( obj, 'beep' );
// returns false
bool = isNonConfigurablePropertyIn( obj, 'boop' );
// returns true
```
## Notes
- Value arguments other than `null` or `undefined` are coerced to `objects`.
```javascript
var bool = isNonConfigurablePropertyIn( 'beep', 'length' );
// returns true
```
- Non-symbol property arguments are coerced to `strings`.
```javascript
var defineProperty = require( '@stdlib/utils/define-property' );
var obj = {};
defineProperty( obj, 'null', {
'configurable': false,
'enumerable': true,
'writable': true,
'value': true
});
var bool = isNonConfigurablePropertyIn( obj, null );
// returns true
```
## Examples
```javascript
var isNonConfigurablePropertyIn = require( '@stdlib/assert/is-nonconfigurable-property-in' );
var bool = isNonConfigurablePropertyIn( [ 'a' ], 'length' );
// returns true
bool = isNonConfigurablePropertyIn( {}, 'toString' );
// returns false
bool = isNonConfigurablePropertyIn( {}, 'hasOwnProperty' );
// returns false
bool = isNonConfigurablePropertyIn( { 'a': 'b' }, 'a' );
// returns false
bool = isNonConfigurablePropertyIn( [ 'a' ], 0 );
// returns false
bool = isNonConfigurablePropertyIn( { 'null': false }, null );
// returns false
bool = isNonConfigurablePropertyIn( { '[object Object]': false }, {} );
// returns false
bool = isNonConfigurablePropertyIn( null, 'a' );
// returns false
bool = isNonConfigurablePropertyIn( void 0, 'a' );
// returns false
```