fix: check this.editor exist before this.editor.off in QueryEditor

`this.editor` might be undefined if error occured during `componentDidMount`, like #665
graphql · Aug 5, 2019 · 1395cee · 1395cee
1 parent 07fc6fe
commit 1395cee
Showing 1 changed file with 6 additions and 4 deletions.
diff --git a/packages/graphiql/src/components/QueryEditor.js b/packages/graphiql/src/components/QueryEditor.js
@@ -193,10 +193,12 @@ export class QueryEditor extends React.Component {
   }
 
   componentWillUnmount() {
-    this.editor.off('change', this._onEdit);
-    this.editor.off('keyup', this._onKeyUp);
-    this.editor.off('hasCompletion', this._onHasCompletion);
-    this.editor = null;
+    if (this.editor) {
+      this.editor.off('change', this._onEdit);
+      this.editor.off('keyup', this._onKeyUp);
+      this.editor.off('hasCompletion', this._onHasCompletion);
+      this.editor = null;  
+    }
   }
 
   render() {