Singlestat/Gauge/BarGauge: Improvements to decimals logic and added test dashboard (#18676)

* Singlevalue: Improvements to decimals logic and added test dashboard

* updated

* Fixed tests

devenv/dev-dashboards/panel-common/auto_decimals.json

@@ -0,0 +1,913 @@
+{
+  "annotations": {
+    "list": [
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+        "builtIn": 1,
+        "datasource": "-- Grafana --",
+        "enable": true,
+        "hide": true,
+        "iconColor": "rgba(0, 211, 255, 1)",
+        "name": "Annotations & Alerts",
+        "type": "dashboard"
+      }
+    ]
+  },
+  "editable": true,
+  "gnetId": null,
+  "graphTooltip": 0,
+  "links": [],
+  "panels": [
+    {
+      "cacheTimeout": null,
+      "gridPos": {
+        "h": 5,
+        "w": 4,
+        "x": 0,
+        "y": 0
+      },
+      "id": 2,
+      "links": [],
+      "options": {
+        "fieldOptions": {
+          "calcs": ["lastNotNull"],
+          "defaults": {
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+                "op": "=",
+                "text": "N/A",
+                "type": 1,
+                "value": "null"
+              }
+            ],
+            "max": 100,
+            "min": 0,
+            "nullValueMode": "connected",
+            "thresholds": [
+              {
+                "color": "green",
+                "value": null
+              },
+              {
+                "color": "red",
+                "value": 80
+              }
+            ],
+            "unit": "none"
+          },
+          "override": {},
+          "values": false
+        },
+        "orientation": "horizontal",
+        "showThresholdLabels": false,
+        "showThresholdMarkers": true
+      },
+      "pluginVersion": "6.4.0-pre",
+      "targets": [
+        {
+          "alias": "",
+          "refId": "A",
+          "scenarioId": "csv_metric_values",
+          "stringInput": "0,0.2"
+        }
+      ],
+      "timeFrom": null,
+      "timeShift": null,
+      "title": "0.2 = 0.2",
+      "type": "gauge"
+    },
+    {
+      "gridPos": {
+        "h": 5,
+        "w": 4,
+        "x": 4,
+        "y": 0
+      },
+      "id": 4,
+      "options": {
+        "fieldOptions": {
+          "calcs": ["lastNotNull"],
+          "defaults": {
+            "mappings": [],
+            "max": 100,
+            "min": 0,
+            "thresholds": [
+              {
+                "color": "green",
+                "value": null
+              },
+              {
+                "color": "red",
+                "value": 80
+              }
+            ],
+            "unit": "short"
+          },
+          "override": {},
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+        },
+        "orientation": "auto",
+        "showThresholdLabels": false,
+        "showThresholdMarkers": true
+      },
+      "pluginVersion": "6.4.0-pre",
+      "targets": [
+        {
+          "alias": "",
+          "refId": "A",
+          "scenarioId": "csv_metric_values",
+          "stringInput": "0,0.0002"
+        }
+      ],
+      "timeFrom": null,
+      "timeShift": null,
+      "title": "0.0002 = 0.0002",
+      "type": "gauge"
+    },
+    {
+      "gridPos": {
+        "h": 5,
+        "w": 4,
+        "x": 8,
+        "y": 0
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+      "options": {
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+          "calcs": ["lastNotNull"],
+          "defaults": {
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+            "max": 100,
+            "min": 0,
+            "thresholds": [
+              {
+                "color": "green",
+                "value": null
+              },
+              {
+                "color": "red",
+                "value": 80
+              }
+            ],
+            "unit": "short"
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+        "orientation": "auto",
+        "showThresholdLabels": false,
+        "showThresholdMarkers": true
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+      "pluginVersion": "6.4.0-pre",
+      "targets": [
+        {
+          "alias": "",
+          "refId": "A",
+          "scenarioId": "csv_metric_values",
+          "stringInput": "0,1.125"
+        }
+      ],
+      "timeFrom": null,
+      "timeShift": null,
+      "title": "1.125 = 1.12",
+      "type": "gauge"
+    },
+    {
+      "gridPos": {
+        "h": 5,
+        "w": 4,
+        "x": 12,
+        "y": 0
+      },
+      "id": 19,
+      "options": {
+        "fieldOptions": {
+          "calcs": ["lastNotNull"],
+          "defaults": {
+            "mappings": [],
+            "max": 100,
+            "min": 0,
+            "thresholds": [
+              {
+                "color": "green",
+                "value": null
+              },
+              {
+                "color": "red",
+                "value": 80
+              }
+            ],
+            "unit": "short"
+          },
+          "override": {},
+          "values": false
+        },
+        "orientation": "auto",
+        "showThresholdLabels": false,
+        "showThresholdMarkers": true
+      },
+      "pluginVersion": "6.4.0-pre",
+      "targets": [
+        {
+          "alias": "",
+          "refId": "A",
+          "scenarioId": "csv_metric_values",
+          "stringInput": "0,2.235"
+        }
+      ],
+      "timeFrom": null,
+      "timeShift": null,
+      "title": "2.235 = 2.2",
+      "type": "gauge"
+    },
+    {
+      "gridPos": {
+        "h": 5,
+        "w": 4,
+        "x": 16,
+        "y": 0
+      },
+      "id": 6,
+      "options": {
+        "fieldOptions": {
+          "calcs": ["lastNotNull"],
+          "defaults": {
+            "mappings": [],
+            "max": 100,
+            "min": 0,
+            "thresholds": [
+              {
+                "color": "green",
+                "value": null
+              },
+              {
+                "color": "red",
+                "value": 80
+              }
+            ],
+            "unit": "short"
+          },
+          "override": {},
+          "values": false
+        },
+        "orientation": "auto",
+        "showThresholdLabels": false,
+        "showThresholdMarkers": true
+      },
+      "pluginVersion": "6.4.0-pre",
+      "targets": [
+        {
+          "alias": "",
+          "refId": "A",
+          "scenarioId": "csv_metric_values",
+          "stringInput": "0,1000"
+        }
+      ],
+      "timeFrom": null,
+      "timeShift": null,
+      "title": "1000 = 1K",
+      "type": "gauge"
+    },
+    {
+      "gridPos": {
+        "h": 5,
+        "w": 4,
+        "x": 20,
+        "y": 0
+      },
+      "id": 7,
+      "options": {
+        "fieldOptions": {
+          "calcs": ["lastNotNull"],
+          "defaults": {
+            "mappings": [],
+            "max": 100,
+            "min": 0,
+            "thresholds": [
+              {
+                "color": "green",
+                "value": null
+              },
+              {
+                "color": "red",
+                "value": 80
+              }
+            ],
+            "unit": "short"
+          },
+          "override": {},
+          "values": false
+        },
+        "orientation": "auto",
+        "showThresholdLabels": false,
+        "showThresholdMarkers": true
+      },
+      "pluginVersion": "6.4.0-pre",
+      "targets": [
+        {
+          "alias": "",
+          "refId": "A",
+          "scenarioId": "csv_metric_values",
+          "stringInput": "0,1200"
+        }
+      ],
+      "timeFrom": null,
+      "timeShift": null,
+      "title": "1200 = 1.2K",
+      "type": "gauge"
+    },
+    {
+      "gridPos": {
+        "h": 5,
+        "w": 4,
+        "x": 0,
+        "y": 5
+      },
+      "id": 8,
+      "options": {
+        "fieldOptions": {
+          "calcs": ["lastNotNull"],
+          "defaults": {
+            "mappings": [],
+            "max": 100,
+            "min": 0,
+            "thresholds": [
+              {
+                "color": "green",
+                "value": null
+              },
+              {
+                "color": "red",
+                "value": 80
+              }
+            ],
+            "unit": "short"
+          },
+          "override": {},
+          "values": false
+        },
+        "orientation": "auto",
+        "showThresholdLabels": false,
+        "showThresholdMarkers": true
+      },
+      "pluginVersion": "6.4.0-pre",
+      "targets": [
+        {
+          "alias": "",
+          "refId": "A",
+          "scenarioId": "csv_metric_values",
+          "stringInput": "0,1250"
+        }
+      ],
+      "timeFrom": null,
+      "timeShift": null,
+      "title": "1250 = 1.25K",
+      "type": "gauge"
+    },
+    {
+      "gridPos": {
+        "h": 5,
+        "w": 4,
+        "x": 4,
+        "y": 5
+      },
+      "id": 9,
+      "options": {
+        "fieldOptions": {
+          "calcs": ["lastNotNull"],
+          "defaults": {
+            "mappings": [],
+            "max": 100,
+            "min": 0,
+            "thresholds": [
+              {
+                "color": "green",
+                "value": null
+              },
+              {
+                "color": "red",
+                "value": 80
+              }
+            ],
+            "unit": "short"
+          },
+          "override": {},
+          "values": false
+        },
+        "orientation": "auto",
+        "showThresholdLabels": false,
+        "showThresholdMarkers": true
+      },
+      "pluginVersion": "6.4.0-pre",
+      "targets": [
+        {
+          "alias": "",
+          "refId": "A",
+          "scenarioId": "csv_metric_values",
+          "stringInput": "0,1500"
+        }
+      ],
+      "timeFrom": null,
+      "timeShift": null,
+      "title": "1500 = 1.5K",
+      "type": "gauge"
+    },
+    {
+      "gridPos": {
+        "h": 5,
+        "w": 4,
+        "x": 8,
+        "y": 5
+      },
+      "id": 10,
+      "options": {
+        "fieldOptions": {
+          "calcs": ["lastNotNull"],
+          "defaults": {
+            "mappings": [],
+            "max": 100,
+            "min": 0,
+            "thresholds": [
+              {
+                "color": "green",
+                "value": null
+              },
+              {
+                "color": "red",
+                "value": 80
+              }
+            ],
+            "unit": "short"
+          },
+          "override": {},
+          "values": false
+        },
+        "orientation": "auto",
+        "showThresholdLabels": false,
+        "showThresholdMarkers": true
+      },
+      "pluginVersion": "6.4.0-pre",
+      "targets": [
+        {
+          "alias": "",
+          "refId": "A",
+          "scenarioId": "csv_metric_values",
+          "stringInput": "0,15258"
+        }
+      ],
+      "timeFrom": null,
+      "timeShift": null,
+      "title": "15258 = 15.26K",
+      "type": "gauge"
+    },
+    {
+      "gridPos": {
+        "h": 5,
+        "w": 4,
+        "x": 12,
+        "y": 5
+      },
+      "id": 5,
+      "options": {
+        "fieldOptions": {
+          "calcs": ["lastNotNull"],
+          "defaults": {
+            "mappings": [],
+            "max": 100,
+            "min": 0,
+            "thresholds": [
+              {
+                "color": "green",
+                "value": null
+              },
+              {
+                "color": "red",
+                "value": 80
+              }
+            ],
+            "unit": "short"
+          },
+          "override": {},
+          "values": false
+        },
+        "orientation": "auto",
+        "showThresholdLabels": false,
+        "showThresholdMarkers": true
+      },
+      "pluginVersion": "6.4.0-pre",
+      "targets": [
+        {
+          "alias": "",
+          "refId": "A",
+          "scenarioId": "csv_metric_values",
+          "stringInput": "0,100.50"
+        }
+      ],
+      "timeFrom": null,
+      "timeShift": null,
+      "title": "100.50 = 101",
+      "type": "gauge"
+    },
+    {
+      "gridPos": {
+        "h": 5,
+        "w": 4,
+        "x": 16,
+        "y": 5
+      },
+      "id": 11,
+      "options": {
+        "fieldOptions": {
+          "calcs": ["lastNotNull"],
+          "defaults": {
+            "mappings": [],
+            "max": 100,
+            "min": 0,
+            "thresholds": [
+              {
+                "color": "green",
+                "value": null
+              },
+              {
+                "color": "red",
+                "value": 80
+              }
+            ],
+            "unit": "short"
+          },
+          "override": {},
+          "values": false
+        },
+        "orientation": "auto",
+        "showThresholdLabels": false,
+        "showThresholdMarkers": true
+      },
+      "pluginVersion": "6.4.0-pre",
+      "targets": [
+        {
+          "alias": "",
+          "refId": "A",
+          "scenarioId": "csv_metric_values",
+          "stringInput": "0,1500000"
+        }
+      ],
+      "timeFrom": null,
+      "timeShift": null,
+      "title": "1500000 = 1.5Mil",
+      "type": "gauge"
+    },
+    {
+      "gridPos": {
+        "h": 5,
+        "w": 4,
+        "x": 20,
+        "y": 5
+      },
+      "id": 13,
+      "options": {
+        "fieldOptions": {
+          "calcs": ["lastNotNull"],
+          "defaults": {
+            "mappings": [],
+            "max": 100,
+            "min": 0,
+            "thresholds": [
+              {
+                "color": "green",
+                "value": null
+              },
+              {
+                "color": "red",
+                "value": 80
+              }
+            ],
+            "unit": "short"
+          },
+          "override": {},
+          "values": false
+        },
+        "orientation": "auto",
+        "showThresholdLabels": false,
+        "showThresholdMarkers": true
+      },
+      "pluginVersion": "6.4.0-pre",
+      "targets": [
+        {
+          "alias": "",
+          "refId": "A",
+          "scenarioId": "csv_metric_values",
+          "stringInput": "0,1000000000"
+        }
+      ],
+      "timeFrom": null,
+      "timeShift": null,
+      "title": "1000000000 = 1 Bil",
+      "type": "gauge"
+    },
+    {
+      "gridPos": {
+        "h": 5,
+        "w": 4,
+        "x": 0,
+        "y": 10
+      },
+      "id": 14,
+      "options": {
+        "fieldOptions": {
+          "calcs": ["lastNotNull"],
+          "defaults": {
+            "mappings": [],
+            "max": 100,
+            "min": 0,
+            "thresholds": [
+              {
+                "color": "green",
+                "value": null
+              },
+              {
+                "color": "red",
+                "value": 80
+              }
+            ],
+            "unit": "short"
+          },
+          "override": {},
+          "values": false
+        },
+        "orientation": "auto",
+        "showThresholdLabels": false,
+        "showThresholdMarkers": true
+      },
+      "pluginVersion": "6.4.0-pre",
+      "targets": [
+        {
+          "alias": "",
+          "refId": "A",
+          "scenarioId": "csv_metric_values",
+          "stringInput": "0,1500000000"
+        }
+      ],
+      "timeFrom": null,
+      "timeShift": null,
+      "title": "1500000000 = 1.5 Bil",
+      "type": "gauge"
+    },
+    {
+      "gridPos": {
+        "h": 5,
+        "w": 4,
+        "x": 4,
+        "y": 10
+      },
+      "id": 15,
+      "options": {
+        "fieldOptions": {
+          "calcs": ["lastNotNull"],
+          "defaults": {
+            "mappings": [],
+            "max": 100,
+            "min": 0,
+            "thresholds": [
+              {
+                "color": "green",
+                "value": null
+              },
+              {
+                "color": "red",
+                "value": 80
+              }
+            ],
+            "unit": "ms"
+          },
+          "override": {},
+          "values": false
+        },
+        "orientation": "auto",
+        "showThresholdLabels": false,
+        "showThresholdMarkers": true
+      },
+      "pluginVersion": "6.4.0-pre",
+      "targets": [
+        {
+          "alias": "",
+          "refId": "A",
+          "scenarioId": "csv_metric_values",
+          "stringInput": "0,1000"
+        }
+      ],
+      "timeFrom": null,
+      "timeShift": null,
+      "title": "1000 (ms) = 1s",
+      "type": "gauge"
+    },
+    {
+      "gridPos": {
+        "h": 5,
+        "w": 4,
+        "x": 8,
+        "y": 10
+      },
+      "id": 16,
+      "options": {
+        "fieldOptions": {
+          "calcs": ["lastNotNull"],
+          "defaults": {
+            "mappings": [],
+            "max": 100,
+            "min": 0,
+            "thresholds": [
+              {
+                "color": "green",
+                "value": null
+              },
+              {
+                "color": "red",
+                "value": 80
+              }
+            ],
+            "unit": "ms"
+          },
+          "override": {},
+          "values": false
+        },
+        "orientation": "auto",
+        "showThresholdLabels": false,
+        "showThresholdMarkers": true
+      },
+      "pluginVersion": "6.4.0-pre",
+      "targets": [
+        {
+          "alias": "",
+          "refId": "A",
+          "scenarioId": "csv_metric_values",
+          "stringInput": "0,1200"
+        }
+      ],
+      "timeFrom": null,
+      "timeShift": null,
+      "title": "1200 (ms) = 1.2s",
+      "type": "gauge"
+    },
+    {
+      "gridPos": {
+        "h": 5,
+        "w": 4,
+        "x": 12,
+        "y": 10
+      },
+      "id": 12,
+      "options": {
+        "fieldOptions": {
+          "calcs": ["lastNotNull"],
+          "defaults": {
+            "mappings": [],
+            "max": 100,
+            "min": 0,
+            "thresholds": [
+              {
+                "color": "green",
+                "value": null
+              },
+              {
+                "color": "red",
+                "value": 80
+              }
+            ],
+            "unit": "short"
+          },
+          "override": {},
+          "values": false
+        },
+        "orientation": "auto",
+        "showThresholdLabels": false,
+        "showThresholdMarkers": true
+      },
+      "pluginVersion": "6.4.0-pre",
+      "targets": [
+        {
+          "alias": "",
+          "refId": "A",
+          "scenarioId": "csv_metric_values",
+          "stringInput": "0,1000000"
+        }
+      ],
+      "timeFrom": null,
+      "timeShift": null,
+      "title": "1000000 = 1 Mil",
+      "type": "gauge"
+    },
+    {
+      "gridPos": {
+        "h": 5,
+        "w": 4,
+        "x": 16,
+        "y": 10
+      },
+      "id": 18,
+      "options": {
+        "fieldOptions": {
+          "calcs": ["lastNotNull"],
+          "defaults": {
+            "mappings": [],
+            "max": 100,
+            "min": 0,
+            "thresholds": [
+              {
+                "color": "green",
+                "value": null
+              },
+              {
+                "color": "red",
+                "value": 80
+              }
+            ],
+            "unit": "ms"
+          },
+          "override": {},
+          "values": false
+        },
+        "orientation": "auto",
+        "showThresholdLabels": false,
+        "showThresholdMarkers": true
+      },
+      "pluginVersion": "6.4.0-pre",
+      "targets": [
+        {
+          "alias": "",
+          "refId": "A",
+          "scenarioId": "csv_metric_values",
+          "stringInput": "0,90000"
+        }
+      ],
+      "timeFrom": null,
+      "timeShift": null,
+      "title": "90000 (ms) = 1.5 min",
+      "type": "gauge"
+    },
+    {
+      "gridPos": {
+        "h": 5,
+        "w": 4,
+        "x": 0,
+        "y": 15
+      },
+      "id": 17,
+      "options": {
+        "fieldOptions": {
+          "calcs": ["lastNotNull"],
+          "defaults": {
+            "mappings": [],
+            "max": 100,
+            "min": 0,
+            "thresholds": [
+              {
+                "color": "green",
+                "value": null
+              },
+              {
+                "color": "red",
+                "value": 80
+              }
+            ],
+            "unit": "ms"
+          },
+          "override": {},
+          "values": false
+        },
+        "orientation": "auto",
+        "showThresholdLabels": false,
+        "showThresholdMarkers": true
+      },
+      "pluginVersion": "6.4.0-pre",
+      "targets": [
+        {
+          "alias": "",
+          "refId": "A",
+          "scenarioId": "csv_metric_values",
+          "stringInput": "0,1200"
+        }
+      ],
+      "timeFrom": null,
+      "timeShift": null,
+      "title": "1860 (ms) = 1.86s",
+      "type": "gauge"
+    }
+  ],
+  "schemaVersion": 19,
+  "style": "dark",
+  "tags": ["gdev", "panel-tests"],
+  "templating": {
+    "list": []
+  },
+  "time": {
+    "from": "now-6h",
+    "to": "now"
+  },
+  "timepicker": {
+    "refresh_intervals": ["5s", "10s", "30s", "1m", "5m", "15m", "30m", "1h", "2h", "1d"]
+  },
+  "timezone": "",
+  "title": "Panel Tests - Auto Decimals",
+  "uid": "5mqG8qdZz",
+  "version": 1
+}

packages/grafana-ui/src/utils/displayProcessor.test.ts

@@ -1,6 +1,5 @@
 import { MappingType, ValueMapping, DisplayProcessor, DisplayValue } from '@grafana/data';
-
-import { getDisplayProcessor, getColorFromThreshold, getDecimalsForValue } from './displayProcessor';
+import { getDisplayProcessor, getColorFromThreshold } from './displayProcessor';
 
 function assertSame(input: any, processors: DisplayProcessor[], match: DisplayValue) {
   processors.forEach(processor => {
@@ -135,17 +134,16 @@ describe('Format value', () => {
   });
 
   it('should set auto decimals, 1 significant', () => {
-    const value = '1.23';
+    const value = 3.23;
     const instance = getDisplayProcessor({ field: { decimals: null } });
-
-    expect(instance(value).text).toEqual('1.2');
+    expect(instance(value).text).toEqual('3.2');
   });
 
   it('should set auto decimals, 2 significant', () => {
-    const value = '0.0245';
+    const value = 0.0245;
     const instance = getDisplayProcessor({ field: { decimals: null } });
 
-    expect(instance(value).text).toEqual('0.02');
+    expect(instance(value).text).toEqual('0.025');
   });
 
   it('should use override decimals', () => {
@@ -164,20 +162,32 @@ describe('Format value', () => {
 
     expect(instance(value).text).toEqual('1-20');
   });
-});
 
-describe('getDecimalsForValue()', () => {
-  it('should calculate reasonable decimals precision for given value', () => {
-    expect(getDecimalsForValue(1.01)).toEqual({ decimals: 1, scaledDecimals: 4 });
-    expect(getDecimalsForValue(9.01)).toEqual({ decimals: 0, scaledDecimals: 2 });
-    expect(getDecimalsForValue(1.1)).toEqual({ decimals: 1, scaledDecimals: 4 });
-    expect(getDecimalsForValue(2)).toEqual({ decimals: 0, scaledDecimals: 2 });
-    expect(getDecimalsForValue(20)).toEqual({ decimals: 0, scaledDecimals: 1 });
-    expect(getDecimalsForValue(200)).toEqual({ decimals: 0, scaledDecimals: 0 });
-    expect(getDecimalsForValue(2000)).toEqual({ decimals: 0, scaledDecimals: 0 });
-    expect(getDecimalsForValue(20000)).toEqual({ decimals: 0, scaledDecimals: -2 });
-    expect(getDecimalsForValue(200000)).toEqual({ decimals: 0, scaledDecimals: -3 });
-    expect(getDecimalsForValue(200000000)).toEqual({ decimals: 0, scaledDecimals: -6 });
-    expect(getDecimalsForValue(100, 2)).toEqual({ decimals: 2, scaledDecimals: null });
+  //
+  // Below is current behavior but I it's clearly not working great
+  //
+
+  it('with value 1000 and unit short', () => {
+    const value = 1000;
+    const instance = getDisplayProcessor({ field: { decimals: null, unit: 'short' } });
+    expect(instance(value).text).toEqual('1.000 K');
+  });
+
+  it('with value 1200 and unit short', () => {
+    const value = 1200;
+    const instance = getDisplayProcessor({ field: { decimals: null, unit: 'short' } });
+    expect(instance(value).text).toEqual('1.200 K');
+  });
+
+  it('with value 1250 and unit short', () => {
+    const value = 1250;
+    const instance = getDisplayProcessor({ field: { decimals: null, unit: 'short' } });
+    expect(instance(value).text).toEqual('1.250 K');
+  });
+
+  it('with value 10000000 and unit short', () => {
+    const value = 1000000;
+    const instance = getDisplayProcessor({ field: { decimals: null, unit: 'short' } });
+    expect(instance(value).text).toEqual('1.000 Mil');
   });
 });

packages/grafana-ui/src/utils/displayProcessor.ts

@@ -127,17 +127,31 @@ export function getColorFromThreshold(value: number, thresholds: Threshold[], th
   return getColorFromHexRgbOrName(thresholds[0].color, themeType);
 }
 
+// function getSignificantDigitCount(n: number): number {
+//   // remove decimal and make positive
+//   n = Math.abs(parseInt(String(n).replace('.', ''), 10));
+//   if (n === 0) {
+//     return 0;
+//   }
+//
+//   // kill the 0s at the end of n
+//   while (n !== 0 && n % 10 === 0) {
+//     n /= 10;
+//   }
+//
+//   // get number of digits
+//   return Math.floor(Math.log(n) / Math.LN10) + 1;
+// }
+
 export function getDecimalsForValue(value: number, decimalOverride?: DecimalCount): DecimalInfo {
   if (_.isNumber(decimalOverride)) {
     // It's important that scaledDecimals is null here
     return { decimals: decimalOverride, scaledDecimals: null };
   }
 
-  const delta = value / 2;
-  let dec = -Math.floor(Math.log(delta) / Math.LN10);
-
+  let dec = -Math.floor(Math.log(value) / Math.LN10) + 1;
   const magn = Math.pow(10, -dec);
-  const norm = delta / magn; // norm is between 1.0 and 10.0
+  const norm = value / magn; // norm is between 1.0 and 10.0
   let size;
 
   if (norm < 1.5) {
@@ -158,7 +172,7 @@ export function getDecimalsForValue(value: number, decimalOverride?: DecimalCoun
   size *= magn;
 
   // reduce starting decimals if not needed
-  if (Math.floor(value) === value) {
+  if (value % 1 === 0) {
     dec = 0;
   }
 

public/app/plugins/panel/singlestat/specs/singlestat.test.ts

@@ -193,7 +193,7 @@ describe('SingleStatCtrl', () => {
   singleStatScenario('When value to text mapping is specified', (ctx: TestContext) => {
     ctx.setup(() => {
       ctx.input = [{ target: 'test.cpu1', datapoints: [[9.9, 1]] }];
-      ctx.ctrl.panel.valueMaps = [{ value: '10', text: 'OK' }];
+      ctx.ctrl.panel.valueMaps = [{ value: '9.9', text: 'OK' }];
     });
 
     it('value should remain', () => {
@@ -291,20 +291,16 @@ describe('SingleStatCtrl', () => {
     singleStatScenario('When value to text mapping is specified', (ctx: TestContext) => {
       ctx.setup(() => {
         ctx.input = tableData;
-        ctx.input[0].rows[0] = [1492759673649, 'ignore1', 9.9, 'ignore2'];
+        ctx.input[0].rows[0] = [1492759673649, 'ignore1', 10, 'ignore2'];
         ctx.ctrl.panel.mappingType = 2;
         ctx.ctrl.panel.tableColumn = 'mean';
         ctx.ctrl.panel.valueMaps = [{ value: '10', text: 'OK' }];
       });
 
       it('value should remain', () => {
-        expect(ctx.data.value).toBe(9.9);
+        expect(ctx.data.value).toBe(10);
       });
 
-      // it('round should be rounded up', () => {
-      //   expect(ctx.data.valueRounded).toBe(10);
-      // });
-
       it('Should replace value with text', () => {
         expect(ctx.data.display.text).toBe('OK');
       });