Field config: Add support for paths in default field config setup (#27570)

* Add support for paths in default field config setup

* Typecheck fix

public/app/features/dashboard/components/PanelEditor/FieldConfigEditor.tsx

-import React, { useCallback, ReactNode } from 'react';
+import React, { ReactNode, useCallback } from 'react';
 import cloneDeep from 'lodash/cloneDeep';
 import {
   DataFrame,
+  DocsId,
   FieldConfigPropertyItem,
   FieldConfigSource,
   PanelPlugin,
   SelectableValue,
   VariableSuggestionsScope,
-  DocsId,
 } from '@grafana/data';
 import { Container, Counter, FeatureInfoBox, Field, fieldMatchersUI, Label, useTheme, ValuePicker } from '@grafana/ui';
 import { getDataLinksVariableSuggestions } from '../../../panel/panellinks/link_srv';
@@ -17,6 +17,7 @@ import { OptionsGroup } from './OptionsGroup';
 import { selectors } from '@grafana/e2e-selectors';
 import { css } from 'emotion';
 import { getDocsLink } from 'app/core/utils/docsLinks';
+import { updateDefaultFieldConfigValue } from './utils';
 
 interface Props {
   plugin: PanelPlugin;
@@ -32,6 +33,7 @@ interface Props {
 export const OverrideFieldConfigEditor: React.FC<Props> = props => {
   const theme = useTheme();
   const { config } = props;
+
   const onOverrideChange = (index: number, override: any) => {
     const { config } = props;
     let overrides = cloneDeep(config.overrides);
@@ -128,32 +130,9 @@ export const OverrideFieldConfigEditor: React.FC<Props> = props => {
 };
 
 export const DefaultFieldConfigEditor: React.FC<Props> = ({ data, onChange, config, plugin }) => {
-  const setDefaultValue = useCallback(
+  const onDefaultValueChange = useCallback(
     (name: string, value: any, isCustom: boolean | undefined) => {
-      const defaults = { ...config.defaults };
-      const remove = value === undefined || value === null || '';
-
-      if (isCustom) {
-        if (defaults.custom) {
-          if (remove) {
-            defaults.custom = { ...defaults.custom };
-            delete defaults.custom[name];
-          } else {
-            defaults.custom = { ...defaults.custom, [name]: value };
-          }
-        } else if (!remove) {
-          defaults.custom = { [name]: value };
-        }
-      } else if (remove) {
-        delete (defaults as any)[name];
-      } else {
-        (defaults as any)[name] = value;
-      }
-
-      onChange({
-        ...config,
-        defaults,
-      });
+      onChange(updateDefaultFieldConfigValue(config, name, value, isCustom));
     },
     [config, onChange]
   );
@@ -187,7 +166,7 @@ export const DefaultFieldConfigEditor: React.FC<Props> = ({ data, onChange, conf
           <item.editor
             item={item}
             value={value}
-            onChange={v => setDefaultValue(item.path, v, item.isCustom)}
+            onChange={v => onDefaultValueChange(item.path, v, item.isCustom)}
             context={{
               data,
               getSuggestions: (scope?: VariableSuggestionsScope) => getDataLinksVariableSuggestions(data, scope),

public/app/features/dashboard/components/PanelEditor/utils.test.ts

-import { FieldConfig, PanelPlugin, standardFieldConfigEditorRegistry } from '@grafana/data';
-import { supportsDataQuery } from './utils';
+import { FieldConfig, FieldConfigSource, PanelPlugin, standardFieldConfigEditorRegistry } from '@grafana/data';
+import { supportsDataQuery, updateDefaultFieldConfigValue } from './utils';
 
 describe('standardFieldConfigEditorRegistry', () => {
   const dummyConfig: FieldConfig = {
@@ -50,3 +50,39 @@ describe('supportsDataQuery', () => {
     });
   });
 });
+
+describe('updateDefaultFieldConfigValue', () => {
+  it.each`
+    property | isCustom | newValue                    | expected
+    ${'a'}   | ${false} | ${2}                        | ${{ a: 2, b: { c: 'nested default' }, custom: { d: 1, e: { f: 'nested custom' } } }}
+    ${'b.c'} | ${false} | ${'nested default updated'} | ${{ a: 1, b: { c: 'nested default updated' }, custom: { d: 1, e: { f: 'nested custom' } } }}
+    ${'a'}   | ${false} | ${undefined}                | ${{ b: { c: 'nested default' }, custom: { d: 1, e: { f: 'nested custom' } } }}
+    ${'b'}   | ${false} | ${undefined}                | ${{ a: 1, custom: { d: 1, e: { f: 'nested custom' } } }}
+    ${'b.c'} | ${false} | ${undefined}                | ${{ a: 1, b: {}, custom: { d: 1, e: { f: 'nested custom' } } }}
+    ${'d'}   | ${true}  | ${2}                        | ${{ a: 1, b: { c: 'nested default' }, custom: { d: 2, e: { f: 'nested custom' } } }}
+    ${'e.f'} | ${true}  | ${'nested custom updated'}  | ${{ a: 1, b: { c: 'nested default' }, custom: { d: 1, e: { f: 'nested custom updated' } } }}
+    ${'d'}   | ${true}  | ${undefined}                | ${{ a: 1, b: { c: 'nested default' }, custom: { e: { f: 'nested custom' } } }}
+    ${'e'}   | ${true}  | ${undefined}                | ${{ a: 1, b: { c: 'nested default' }, custom: { d: 1 } }}
+    ${'e.f'} | ${true}  | ${undefined}                | ${{ a: 1, b: { c: 'nested default' }, custom: { d: 1, e: {} } }}
+  `(
+    'when updating property:$property (is custom: $isCustom) with $newValue',
+    ({ property, isCustom, newValue, expected }) => {
+      const config = {
+        defaults: {
+          a: 1,
+          b: {
+            c: 'nested default',
+          },
+          custom: {
+            d: 1,
+            e: { f: 'nested custom' },
+          },
+        },
+        overrides: [],
+      };
+      expect(updateDefaultFieldConfigValue(config as FieldConfigSource, property, newValue, isCustom).defaults).toEqual(
+        expected
+      );
+    }
+  );
+});

public/app/features/dashboard/components/PanelEditor/utils.ts

 import { CSSProperties } from 'react';
+import { set as lodashSet, omit } from 'lodash';
+import { FieldConfigSource, PanelPlugin } from '@grafana/data';
 import { PanelModel } from '../../state/PanelModel';
 import { DisplayMode } from './types';
 import { GRID_CELL_HEIGHT, GRID_CELL_VMARGIN, GRID_COLUMN_COUNT } from 'app/core/constants';
-import { PanelPlugin } from '@grafana/data';
 
 export function calculatePanelSize(mode: DisplayMode, width: number, height: number, panel: PanelModel): CSSProperties {
   if (mode === DisplayMode.Fill) {
@@ -29,3 +30,34 @@ export function calculatePanelSize(mode: DisplayMode, width: number, height: num
 export function supportsDataQuery(plugin: PanelPlugin | undefined): boolean {
   return plugin?.meta.skipDataQuery === false;
 }
+
+export const updateDefaultFieldConfigValue = (
+  config: FieldConfigSource,
+  name: string,
+  value: any,
+  isCustom?: boolean
+) => {
+  let defaults = { ...config.defaults };
+  const remove = value === undefined || value === null || '';
+
+  if (isCustom) {
+    if (defaults.custom) {
+      if (remove) {
+        defaults.custom = omit(defaults.custom, name);
+      } else {
+        defaults.custom = lodashSet({ ...defaults.custom }, name, value);
+      }
+    } else if (!remove) {
+      defaults.custom = lodashSet({ ...defaults.custom }, name, value);
+    }
+  } else if (remove) {
+    defaults = omit(defaults, name);
+  } else {
+    defaults = lodashSet({ ...defaults }, name, value);
+  }
+
+  return {
+    ...config,
+    defaults,
+  };
+};