# isReadOnlyPropertyIn
> Test if an object's own or inherited property is [read-only][@stdlib/utils/define-read-only-property].
## Usage
```javascript
var isReadOnlyPropertyIn = require( '@stdlib/assert/is-read-only-property-in' );
```
#### isReadOnlyPropertyIn( value, property )
Returns a `boolean` indicating if a `value` has a [read-only][@stdlib/utils/define-read-only-property] `property`.
```javascript
var defineProperty = require( '@stdlib/utils/define-property' );
var bool;
var obj;
function Foo() {
this.foo = 'bar';
return this;
}
defineProperty( Foo.prototype, 'beep', {
'configurable': false,
'enumerable': false,
'writable': false,
'value': 'boop'
});
defineProperty( Foo.prototype, 'accessor', {
'configurable': false,
'enumerable': true,
'get': function getter() {
return obj.foo;
}
});
obj = new Foo();
bool = isReadOnlyPropertyIn( obj, 'foo' );
// returns false
bool = isReadOnlyPropertyIn( obj, 'beep' );
// returns true
bool = isReadOnlyPropertyIn( obj, 'accessor' );
// returns true
```
## Notes
- Value arguments other than `null` or `undefined` are coerced to `objects`.
```javascript
var bool = isReadOnlyPropertyIn( 'beep', 'length' );
// returns true
```
- Property arguments are coerced to `strings`.
```javascript
var defineProperty = require( '@stdlib/utils/define-property' );
var obj = {};
defineProperty( obj, 'null', {
'configurable': false,
'enumerable': true,
'writable': false,
'value': true
});
var bool = isReadOnlyPropertyIn( obj, null );
// returns true
```
## Examples
```javascript
var isReadOnlyPropertyIn = require( '@stdlib/assert/is-read-only-property-in' );
var bool = isReadOnlyPropertyIn( 'a', 'length' );
// returns true
bool = isReadOnlyPropertyIn( { 'a': 'b' }, 'a' );
// returns false
bool = isReadOnlyPropertyIn( [ 'a' ], 0 );
// returns false
bool = isReadOnlyPropertyIn( { 'null': false }, null );
// returns false
bool = isReadOnlyPropertyIn( { '[object Object]': false }, {} );
// returns false
bool = isReadOnlyPropertyIn( {}, 'toString' );
// returns false
bool = isReadOnlyPropertyIn( {}, 'hasOwnProperty' );
// returns false
bool = isReadOnlyPropertyIn( null, 'a' );
// returns false
bool = isReadOnlyPropertyIn( void 0, 'a' );
// returns false
```
[@stdlib/utils/define-read-only-property]: https://www.npmjs.com/package/@stdlib/utils-define-read-only-property