@stdlib/assert/is-data-property/README.md

Standard assertion utilities.

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# isDataProperty

> Test if an object's own property has a data descriptor.

<section class="usage">

## Usage

```javascript
var isDataProperty = require( '@stdlib/assert/is-data-property' );
```

#### isDataProperty( value, property )

Returns a `boolean` indicating if a `value` has a data `property`.

<!-- eslint-disable no-restricted-syntax -->

```javascript
var defineProperty = require( '@stdlib/utils/define-property' );

var obj = {
    'foo': 'bar'
};

defineProperty( obj, 'beep', {
    'configurable': false,
    'enumerable': false,
    'writable': false,
    'value': 'boop'
});

defineProperty( obj, 'accessor', {
    'configurable': false,
    'enumerable': false,
    'get': function getter() {
        return obj.foo;
    },
    'set': function setter( v ) {
        obj.foo = v;
    }
});

var bool = isDataProperty( obj, 'foo' );
// returns true

bool = isDataProperty( obj, 'beep' );
// returns true

bool = isDataProperty( obj, 'accessor' );
// returns false
```

</section>

<!-- /.usage -->

<section class="notes">

## Notes

-   Value arguments other than `null` or `undefined` are coerced to `objects`.

    ```javascript
    var bool = isDataProperty( 'beep', 'length' );
    // returns true
    ```

-   Non-symbol property arguments are coerced to `strings`.

    ```javascript
    var obj = {
        'null': 'foo'
    };

    var bool = isDataProperty( obj, null );
    // returns true
    ```

</section>

<!-- /.notes -->

<section class="examples">

## Examples

<!-- eslint-disable object-curly-newline -->

<!-- eslint no-undef: "error" -->

```javascript
var isDataProperty = require( '@stdlib/assert/is-data-property' );

var bool = isDataProperty( [ 'a' ], 'length' );
// returns true

bool = isDataProperty( { 'a': 'b' }, 'a' );
// returns true

bool = isDataProperty( [ 'a' ], 0 );
// returns true

bool = isDataProperty( { 'null': false }, null );
// returns true

bool = isDataProperty( { '[object Object]': false }, {} );
// returns true

bool = isDataProperty( {}, 'toString' );
// returns false

bool = isDataProperty( {}, 'hasOwnProperty' );
// returns false

bool = isDataProperty( null, 'a' );
// returns false

bool = isDataProperty( void 0, 'a' );
// returns false
```

</section>

<!-- /.examples -->

<!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->

<section class="related">

* * *

## See Also

-   <span class="package-name">[`@stdlib/assert/has-own-property`][@stdlib/assert/has-own-property]</span><span class="delimiter">: </span><span class="description">test if an object has a specified property.</span>
-   <span class="package-name">[`@stdlib/assert/is-accessor-property`][@stdlib/assert/is-accessor-property]</span><span class="delimiter">: </span><span class="description">test if an object's own property has an accessor descriptor.</span>
-   <span class="package-name">[`@stdlib/assert/is-data-property-in`][@stdlib/assert/is-data-property-in]</span><span class="delimiter">: </span><span class="description">test if an object's own or inherited property has a data descriptor.</span>

</section>

<!-- /.related -->

<!-- Section for all links. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="links">

<!-- <related-links> -->

[@stdlib/assert/has-own-property]: https://github.com/stdlib-js/assert/tree/main/has-own-property

[@stdlib/assert/is-accessor-property]: https://github.com/stdlib-js/assert/tree/main/is-accessor-property

[@stdlib/assert/is-data-property-in]: https://github.com/stdlib-js/assert/tree/main/is-data-property-in

<!-- </related-links> -->

</section>

<!-- /.links -->