From 7b835f980c626771ca66a65c80a4ed0f39db476c Mon Sep 17 00:00:00 2001
From: Wylie Conlon <william.conlon@elastic.co>
Date: Tue, 23 Feb 2021 12:42:56 -0500
Subject: [PATCH] [TSVB] Stop inserting zeroes for null series (#90861)
 (#92432)

* [TSVB] Stop inserting zeroes for null series

* Replace empty default value with hyphen

* Stop treating 0 as false

* Fix test cases

Co-authored-by: Kibana Machine <42973632+kibanamachine@users.noreply.github.com>

Co-authored-by: Kibana Machine <42973632+kibanamachine@users.noreply.github.com>
---
 .../vis_type_timeseries/common/get_last_value.js   |  8 ++++----
 .../common/get_last_value.test.js                  | 14 +++++++++++---
 .../application/visualizations/views/gauge.js      |  2 +-
 .../application/visualizations/views/metric.js     |  2 +-
 .../apps/dashboard/dashboard_filtering.ts          |  4 ++--
 5 files changed, 19 insertions(+), 11 deletions(-)

diff --git a/src/plugins/vis_type_timeseries/common/get_last_value.js b/src/plugins/vis_type_timeseries/common/get_last_value.js
index 9d5ad4c264c9..5a36a5e099f9 100644
--- a/src/plugins/vis_type_timeseries/common/get_last_value.js
+++ b/src/plugins/vis_type_timeseries/common/get_last_value.js
@@ -8,13 +8,13 @@
 
 import { isArray, last } from 'lodash';
 
-const DEFAULT_VALUE = 0;
-const extractValue = (data) => (data && data[1]) || null;
+const DEFAULT_VALUE = '-';
+const extractValue = (data) => (data && data[1]) ?? null;
 
 export const getLastValue = (data, defaultValue = DEFAULT_VALUE) => {
   if (!isArray(data)) {
-    return data || defaultValue;
+    return data ?? defaultValue;
   }
 
-  return extractValue(last(data)) || defaultValue;
+  return extractValue(last(data)) ?? defaultValue;
 };
diff --git a/src/plugins/vis_type_timeseries/common/get_last_value.test.js b/src/plugins/vis_type_timeseries/common/get_last_value.test.js
index e4192de2392e..122f037ddf3e 100644
--- a/src/plugins/vis_type_timeseries/common/get_last_value.test.js
+++ b/src/plugins/vis_type_timeseries/common/get_last_value.test.js
@@ -13,12 +13,20 @@ describe('getLastValue(data)', () => {
     expect(getLastValue('foo')).toBe('foo');
   });
 
+  test('should returns 0 as a value when not an array', () => {
+    expect(getLastValue(0)).toBe(0);
+  });
+
   test('should returns the last value', () => {
     expect(getLastValue([[1, 2]])).toBe(2);
   });
 
+  test('should return 0 as a valid value', () => {
+    expect(getLastValue([[0, 0]])).toBe(0);
+  });
+
   test('should returns the default value ', () => {
-    expect(getLastValue()).toBe(0);
+    expect(getLastValue()).toBe('-');
   });
 
   test('should returns 0 if second to last is not defined (default)', () => {
@@ -27,10 +35,10 @@ describe('getLastValue(data)', () => {
         [1, null],
         [2, null],
       ])
-    ).toBe(0);
+    ).toBe('-');
   });
 
   test('should allows to override the default value', () => {
-    expect(getLastValue(null, '-')).toBe('-');
+    expect(getLastValue(null, 'default')).toBe('default');
   });
 });
diff --git a/src/plugins/vis_type_timeseries/public/application/visualizations/views/gauge.js b/src/plugins/vis_type_timeseries/public/application/visualizations/views/gauge.js
index c7287f79dfdb..31ea3412972e 100644
--- a/src/plugins/vis_type_timeseries/public/application/visualizations/views/gauge.js
+++ b/src/plugins/vis_type_timeseries/public/application/visualizations/views/gauge.js
@@ -61,7 +61,7 @@ export class Gauge extends Component {
   render() {
     const { metric, type } = this.props;
     const { scale, translateX, translateY } = this.state;
-    const value = (metric && getLastValue(metric.data)) || 0;
+    const value = metric && getLastValue(metric.data);
     const max = (metric && getValueBy('max', metric.data)) || 1;
     const formatter =
       (metric && (metric.tickFormatter || metric.formatter)) ||
diff --git a/src/plugins/vis_type_timeseries/public/application/visualizations/views/metric.js b/src/plugins/vis_type_timeseries/public/application/visualizations/views/metric.js
index e5b368aefa2e..17cadb94457b 100644
--- a/src/plugins/vis_type_timeseries/public/application/visualizations/views/metric.js
+++ b/src/plugins/vis_type_timeseries/public/application/visualizations/views/metric.js
@@ -58,7 +58,7 @@ export class Metric extends Component {
     const { metric, secondary } = this.props;
     const { scale, translateX, translateY } = this.state;
     const primaryFormatter = (metric && (metric.tickFormatter || metric.formatter)) || ((n) => n);
-    const primaryValue = primaryFormatter(getLastValue((metric && metric.data) || 0));
+    const primaryValue = primaryFormatter(getLastValue(metric && metric.data));
     const styles = reactcss(
       {
         default: {
diff --git a/test/functional/apps/dashboard/dashboard_filtering.ts b/test/functional/apps/dashboard/dashboard_filtering.ts
index 2aa24fc8b706..e995bc4e52c4 100644
--- a/test/functional/apps/dashboard/dashboard_filtering.ts
+++ b/test/functional/apps/dashboard/dashboard_filtering.ts
@@ -110,7 +110,7 @@ export default function ({ getService, getPageObjects }: FtrProviderContext) {
       });
 
       it('tsvb top n is filtered', async () => {
-        await dashboardExpect.tsvbTopNValuesExist(['0', '0']);
+        await dashboardExpect.tsvbTopNValuesExist(['-', '-']);
       });
 
       it('saved search is filtered', async () => {
@@ -172,7 +172,7 @@ export default function ({ getService, getPageObjects }: FtrProviderContext) {
       });
 
       it('tsvb top n is filtered', async () => {
-        await dashboardExpect.tsvbTopNValuesExist(['0', '0']);
+        await dashboardExpect.tsvbTopNValuesExist(['-', '-']);
       });
 
       it('saved search is filtered', async () => {