title: Props not being passed to React component
body: <p>I'm trying to pass some values as props to one component that I have 
  (Product).</p>
  
  <p>It seems when I console.log(JSON.stringify(props)), the result is: {}.</p>
  
  <p>What can i possibly may be doing wrong?</p>
  
  <pre><code>export default class ProductList extends Component {
      constructor(props) {
          super(props);
  
          this.state = {
              productList: [],
          }
      };
  
      componentWillMount() {
          fetch('http://localhost:9000/api/products/getSixProducts?pageNumber=1')
              .then((res) =&gt; res.json())
              .then(((products) =&gt; products.map((product, index) =&gt; {
                  this.state.productList.push(
                      &lt;Product
                          key={index}
                          id={product._id}
                          brandId={product.brandId}
                          image={product.image}
                          price={product.price}
                          priceDiscounted={product.priceDiscounted}
                          subtitle={product.subtitle}
                      /&gt;)
              })))
  
              .catch(this.setState({ productList: [-1] }))
  ...
  
  </code></pre>
  
  <p>This is my Product constructor:</p>
  
  <pre><code>...
      constructor(props) {
          super(props);
          this.state = {
              id: props.id,
              brandId: props.brandId,
              subtitle: props.subtitle,
              price: props.price,
              priceDiscounted: props.priceDiscounted,
              image: { productImage }
          }
          console.log(JSON.stringify(props));
      }
  ...
  </code></pre>