Sparkline: Improve min/max logic to avoid issues for very narrow deltas (#115030)

* Sparkline: Prevent infinite loop when rendering a sparkline with a single value

* some tests for this case

* refactor out utils, experiment with getting highlightIndex working

* add comments throughout for #112977

* remove unused import

* Update Sparkline.test.tsx

* fix points mode rendering

* Sparkline: Improve min/max logic to avoid issues for very narrow deltas

* spread all config

* defaults deep

* delete unused import

* remove go.work.sum delta

* line break at end of file

packages/grafana-data/src/field/fieldOverrides.test.ts

@@ -253,7 +253,7 @@ describe('applyFieldOverrides', () => {
       ],
     });
 
-    it('will apply field overrides to the fields within the frame', () => {
+    it('will apply default field overrides to the fields within the frame', () => {
       const f0 = createDataFrame({
         name: 'A',
         fields: [
@@ -285,6 +285,41 @@ describe('applyFieldOverrides', () => {
       expect(withOverrides[0].fields[1].values[0].fields[1].state.range.max).toBe(30);
     });
 
+    it('will apply targeted field overrides to the fields within the frame', () => {
+      const f0 = createDataFrame({
+        name: 'A',
+        fields: [
+          {
+            name: 'message',
+            type: FieldType.string,
+            values: ['foo'],
+          },
+          {
+            name: 'frame',
+            type: FieldType.frame,
+            values: [f0Internal],
+          },
+        ],
+      });
+      const withOverrides = applyFieldOverrides({
+        data: [f0],
+        fieldConfig: {
+          defaults: {},
+          overrides: [
+            {
+              matcher: { id: FieldMatcherID.byName, options: 'frame' },
+              properties: [{ id: 'max', value: 30 }],
+            },
+          ],
+        },
+        replaceVariables: (value) => value,
+        theme: createTheme(),
+        fieldConfigRegistry: customFieldRegistry,
+      });
+
+      expect(withOverrides[0].fields[1].values[0].fields[1].config.max).toBe(30);
+    });
+
     it('will not crash when some of the nested frames are undefined', () => {
       const f0 = createDataFrame({
         name: 'A',

packages/grafana-data/src/field/fieldOverrides.ts

@@ -1,4 +1,4 @@
-import { isNumber, set, unset, get, cloneDeep } from 'lodash';
+import { isNumber, set, unset, get, cloneDeep, defaultsDeep } from 'lodash';
 import { createContext, useContext, useMemo, useRef } from 'react';
 import { usePrevious } from 'react-use';
 
@@ -240,9 +240,14 @@ export function applyFieldOverrides(options: ApplyFieldOverrideOptions): DataFra
           ...options,
           // nested frames can be `undefined` in certain situations, like after `merge` transform due to padding the value array.
           // let's replace them with empty frames to avoid errors applying overrides
-          data: field.values.map(
-            (nestedFrame: DataFrame | undefined): DataFrame => nestedFrame ?? createDataFrame({ fields: [] })
-          ),
+          data: field.values.map((nestedFrame: DataFrame | undefined): DataFrame => {
+            const result = nestedFrame ?? createDataFrame({ fields: [] });
+            result.fields = result.fields.map((newField) => {
+              newField.config = defaultsDeep(newField.config || {}, config);
+              return newField;
+            });
+            return result;
+          }),
         });
       }
     }
@@ -256,7 +261,7 @@ function calculateRange(
   field: Field,
   globalRange: NumericRange | undefined,
   data: DataFrame[]
-): { range?: { min?: number | null; max?: number | null; delta: number }; newGlobalRange: NumericRange | undefined } {
+): { range?: NumericRange; newGlobalRange?: NumericRange } {
   // If range is defined with min/max, use it
   if (isNumber(config.min) && isNumber(config.max)) {
     const range = { min: config.min, max: config.max, delta: config.max - config.min };