From a9b407367fd169ab6a03ac41d1be804df1a77489 Mon Sep 17 00:00:00 2001
From: Tom Jenkins <tom@itsravenous.com>
Date: Fri, 11 Dec 2015 10:52:07 +0000
Subject: [PATCH 1/2] Update internal state if previewing prop updated after
 mount.

---
 src/components/markdown-editor.jsx | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/components/markdown-editor.jsx b/src/components/markdown-editor.jsx
index 2e14fa8..c301068 100644
--- a/src/components/markdown-editor.jsx
+++ b/src/components/markdown-editor.jsx
@@ -54,6 +54,15 @@ export default class MarkdownEditor extends React.Component {
         this.setState({previewing: !!this.props.previewing});
     }
 
+    componentWillReceiveProps(nextProps) {
+        // If previewing prop has changed, update internal state
+        if (typeof nextProps.previewing === 'boolean') {
+            this.setState({
+                previewing: nextProps.previewing
+            });
+        }
+    }
+
     render() {
         var previewIcon;
         if (this.state.previewing) {

From 59d5b1b79307066c4ea17d9373b89790e7a22512 Mon Sep 17 00:00:00 2001
From: Tom Jenkins <tom@itsravenous.com>
Date: Fri, 11 Dec 2015 11:32:28 +0000
Subject: [PATCH 2/2] Add test for previewing prop change

---
 test/components/markdown-editor-test.js | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/test/components/markdown-editor-test.js b/test/components/markdown-editor-test.js
index e38b8a5..8c69e2e 100644
--- a/test/components/markdown-editor-test.js
+++ b/test/components/markdown-editor-test.js
@@ -113,6 +113,28 @@ describe('MarkdownEditor', () => {
         });
     });
 
+    describe("#componentWillReceiveProps", () => {
+        it("should set state.previewing to the value of the previewing prop (after mount)", () => {
+            // We can't manipulate props of editor directly, so create a parent component to do it via render
+            var TestParent = React.createFactory(React.createClass({
+              getInitialState() {
+                return {
+                  previewing: true
+                };
+              },
+              render() {
+                return <MarkdownEditor ref="editor" previewing={this.state.previewing} value="##blah blash"  />
+              }
+            }));
+
+            var parent = TestUtils.renderIntoDocument(TestParent());
+            parent.setState({
+              previewing: false
+            });
+            expect(parent.refs.editor.state.previewing).to.be.false;
+        });
+    });
+
     describe("#render", () => {
         [["insert-link", "InsertLink"],
          ["insert-image", "InsertImage"],