From 151b40ee2fd88b500af39a2186054ae859c66207 Mon Sep 17 00:00:00 2001
From: Tobias Skarhed <dehrax@users.noreply.github.com>
Date: Wed, 7 Aug 2019 13:25:09 +0200
Subject: [PATCH] Markdown: Handle undefined/null strings (#18433)

---
 packages/grafana-data/src/utils/markdown.test.ts | 8 ++++++++
 packages/grafana-data/src/utils/markdown.ts      | 4 ++--
 2 files changed, 10 insertions(+), 2 deletions(-)
 create mode 100644 packages/grafana-data/src/utils/markdown.test.ts

diff --git a/packages/grafana-data/src/utils/markdown.test.ts b/packages/grafana-data/src/utils/markdown.test.ts
new file mode 100644
index 00000000000..3df231c77d4
--- /dev/null
+++ b/packages/grafana-data/src/utils/markdown.test.ts
@@ -0,0 +1,8 @@
+import { renderMarkdown } from './markdown';
+
+describe('Markdown wrapper', () => {
+  it('should be able to handle undefined value', () => {
+    const str = renderMarkdown(undefined);
+    expect(str).toBe('');
+  });
+});
diff --git a/packages/grafana-data/src/utils/markdown.ts b/packages/grafana-data/src/utils/markdown.ts
index 8a0ce6c839f..04650a2090d 100644
--- a/packages/grafana-data/src/utils/markdown.ts
+++ b/packages/grafana-data/src/utils/markdown.ts
@@ -15,6 +15,6 @@ export function setMarkdownOptions(optionsOverride?: MarkedOptions) {
   marked.setOptions({ ...defaultMarkedOptions, ...optionsOverride });
 }
 
-export function renderMarkdown(str: string): string {
-  return marked(str);
+export function renderMarkdown(str?: string): string {
+  return marked(str || '');
 }