Plain Object

A plain object

• Inherits directly from Object.prototype or null
• Is not a constructor's prototype property

plain-object/is

Confirms if given object is a plain object

```javascript const isPlainObject = require("type/plain-object/is");

isPlainObject({}); // true isPlainObject(Object.create(null)); // true isPlainObject([]); // false ```

plain-object/ensure

If given argument is a plain object it is returned back. Otherwise TypeError is thrown.

```javascript const ensurePlainObject = require("type/plain-object/ensure");

ensurePlainObject({}); // {} ensurePlainObject("foo"); // Thrown TypeError: foo is not a plain object ```

Confirming on keys

Keys can be validated by passing allowedKeys option. Note that in this case:

• Error message lists up to three invalid keys

```javascript const allowedKeys = ["foo"];

ensurePlainObject({}, { allowedKeys }); // {} ensurePlainObject({ foo: "bar" }, { allowedKeys }); // { foo: 'bar' }

/ Below invocation with crash with: TypeError: [object Object] is not a valid plain object. Following keys are unexpected: lorem, ipsum / ensurePlainObject({ foo: "bar", lorem: 1, ipsum: 2 }, { allowedKeys }); ```

Confirming on property values

Property values can be validated by passing ensurePropertyValue option. Note that in this case:

• A newly created instance of plain object with coerced values is returned
• Error message lists up to three keys that contain invalid values

```javascript const ensureString = require("type/string/ensure");

ensurePlainObject({ foo: 12 }, { ensurePropertyValue: ensureString }); // { foo: '12' }

/ Below invocation with crash with: TypeError: [object Object] is not a valid plain object. Valuees for following keys are invalid: lorem, ipsum / ensurePlainObject({ foo: 23, lorem: {}, ipsum: {} }, { ensurePropertyValue: ensureString }); ```