feat: get hot reloading working for js code snippets

plugins/gatsby-transformer-home-example-code/gatsby-node.js

@@ -1,6 +1,5 @@
 const crypto = require(`crypto`);
 
-// docblock goes here
 const createContentDigest = obj =>
   crypto
     .createHash(`md5`)
@@ -9,7 +8,7 @@ const createContentDigest = obj =>
 
 // Store code snippets in GraphQL for the home page examples.
 // Snippets will be matched with markdown templates of the same name.
-exports.onCreateNode = async ({node, loadNodeContent, actions}) => {
+exports.onCreateNode = async ({actions, node, loadNodeContent}) => {
   const {createNode} = actions;
   const {absolutePath, ext, name, relativeDirectory, sourceInstanceName} = node;
 

src/components/CodeEditor/CodeEditor.js

@@ -35,6 +35,10 @@ class CodeEditor extends Component {
   componentDidUpdate(prevProps, prevState) {
     if (prevState.compiled !== this.state.compiled) {
       this._render();
+    } else if (this.props.code !== prevProps.code) {
+      this.setState({
+        code: this.props.code,
+      });
     }
   }