From 137b67caf3012b30ce99390483993a30d49229a2 Mon Sep 17 00:00:00 2001
From: Maxime Beauchemin <maximebeauchemin@gmail.com>
Date: Wed, 14 Aug 2019 14:34:55 -0700
Subject: [PATCH 1/2] fix: datasource save raises React error

---
 .../assets/src/explore/components/controls/MetricsControl.jsx   | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/superset/assets/src/explore/components/controls/MetricsControl.jsx b/superset/assets/src/explore/components/controls/MetricsControl.jsx
index 9498b08752402..cbb4aa8fa1abc 100644
--- a/superset/assets/src/explore/components/controls/MetricsControl.jsx
+++ b/superset/assets/src/explore/components/controls/MetricsControl.jsx
@@ -54,6 +54,8 @@ const propTypes = {
 const defaultProps = {
   onChange: () => {},
   clearable: true,
+  savedMetrics: [],
+  columns: [],
 };
 
 function isDictionaryForAdhocMetric(value) {

From 055eaa9554f088d29252e234278c9b4cad11991e Mon Sep 17 00:00:00 2001
From: Maxime Beauchemin <maximebeauchemin@gmail.com>
Date: Wed, 14 Aug 2019 17:42:47 -0700
Subject: [PATCH 2/2] add test

---
 .../javascripts/explore/components/MetricsControl_spec.jsx | 7 +++++++
 .../src/explore/components/controls/MetricsControl.jsx     | 4 ++--
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/superset/assets/spec/javascripts/explore/components/MetricsControl_spec.jsx b/superset/assets/spec/javascripts/explore/components/MetricsControl_spec.jsx
index 143bf8f99f900..b6fbf1bacd3bc 100644
--- a/superset/assets/spec/javascripts/explore/components/MetricsControl_spec.jsx
+++ b/superset/assets/spec/javascripts/explore/components/MetricsControl_spec.jsx
@@ -368,5 +368,12 @@ describe('MetricsControl', () => {
       wrapper.setProps({ ...props, columns: [] });
       expect(onChange.calledOnce).toEqual(false);
     });
+    it('Does not fail if no columns or savedMetrics are passed', () => {
+      const { wrapper } = setup({
+        savedMetrics: null,
+        columns: null,
+      });
+      expect(wrapper.exists('.metrics-select')).toEqual(true);
+    });
   });
 });
diff --git a/superset/assets/src/explore/components/controls/MetricsControl.jsx b/superset/assets/src/explore/components/controls/MetricsControl.jsx
index cbb4aa8fa1abc..a998283f0ccfd 100644
--- a/superset/assets/src/explore/components/controls/MetricsControl.jsx
+++ b/superset/assets/src/explore/components/controls/MetricsControl.jsx
@@ -64,7 +64,7 @@ function isDictionaryForAdhocMetric(value) {
 
 function columnsContainAllMetrics(value, nextProps) {
   const columnNames = new Set(
-    [...nextProps.columns, ...nextProps.savedMetrics]
+    [...(nextProps.columns || []), ...(nextProps.savedMetrics || [])]
     // eslint-disable-next-line camelcase
       .map(({ column_name, metric_name }) => (column_name || metric_name)),
   );
@@ -245,7 +245,7 @@ export default class MetricsControl extends React.PureComponent {
       Object.keys(AGGREGATES).map(aggregate => ({ aggregate_name: aggregate })) :
       [];
     const options = [
-      ...columns,
+      ...(columns || []),
       ...aggregates,
       ...(savedMetrics || []),
     ];