component: apply PropType plugin to props

src/components/Burger/BurgerIngredient/BurgerIngredient.js

@@ -1,10 +1,13 @@
-import React from 'react';
+import React, { Component } from 'react';
+import PropTypes from 'prop-types';
+
 import classes from './burgerIngredient.css';
 
-const burgerIngredient = (props) => {
+class BurgerIngredient extends Component {
+    render() {
         let ingredient = null;
 
-    switch (props.type) {
+        switch (this.props.type) {
             case ('bread-bottom'):
                 ingredient = <div className={classes.BreadBottom}></div>
                 break;
@@ -32,8 +35,12 @@ const burgerIngredient = (props) => {
                 ingredient = null;
                 break;
         }
-
         return ingredient;
+    }
 }
 
+BurgerIngredient.PropTypes = {
+    type: PropTypes.string.isRequired
+};
+
 export default burgerIngredient;