Explore: Ensure old panes are removed before opening split view (#70670)

public/app/features/explore/state/explorePane.ts

@@ -94,7 +94,7 @@ export function changeSize(exploreId: string, { width }: { width: number }): Pay
   return changeSizeAction({ exploreId, width });
 }
 
-interface InitializeExploreOptions {
+export interface InitializeExploreOptions {
   exploreId: string;
   datasource: DataSourceRef | string | undefined;
   queries: DataQuery[];

public/app/features/explore/state/main.test.ts

@@ -7,9 +7,10 @@ import { PanelModel } from 'app/features/dashboard/state';
 
 import { reducerTester } from '../../../../test/core/redux/reducerTester';
 import { MockDataSourceApi } from '../../../../test/mocks/datasource_srv';
-import { ExploreItemState, ExploreState } from '../../../types';
+import { configureStore } from '../../../store/configureStore';
+import { ExploreItemState, ExploreState, StoreState, ThunkDispatch } from '../../../types';
 
-import { exploreReducer, navigateToExplore, splitClose } from './main';
+import { exploreReducer, navigateToExplore, splitClose, splitOpen } from './main';
 
 const getNavigateToExploreContext = async (openInNewWindow?: (url: string) => void) => {
   const url = '/explore';
@@ -116,6 +117,35 @@ describe('navigateToExplore', () => {
 
 describe('Explore reducer', () => {
   describe('split view', () => {
+    describe('split open', () => {
+      it('it should create only ony new pane', async () => {
+        let dispatch: ThunkDispatch, getState: () => StoreState;
+
+        const store: { dispatch: ThunkDispatch; getState: () => StoreState } = configureStore({
+          explore: {
+            panes: {
+              one: { queries: [], range: {} },
+            },
+          },
+        } as unknown as Partial<StoreState>);
+
+        dispatch = store.dispatch;
+        getState = store.getState;
+
+        await dispatch(splitOpen());
+        let splitPanes = Object.keys(getState().explore.panes);
+        expect(splitPanes).toHaveLength(2);
+        let secondSplitPaneId = splitPanes[1];
+
+        await dispatch(splitOpen());
+        splitPanes = Object.keys(getState().explore.panes);
+        // only 2 panes exist...
+        expect(splitPanes).toHaveLength(2);
+        // ...and the second pane is replaced
+        expect(splitPanes[0]).toBe('one');
+        expect(splitPanes[1]).not.toBe(secondSplitPaneId);
+      });
+    });
     describe('split close', () => {
       it('should reset right pane when it is closed', () => {
         const leftItemMock = {

public/app/features/explore/state/main.ts

@@ -14,7 +14,7 @@ import { CorrelationData } from '../../correlations/useCorrelations';
 import { TimeSrv } from '../../dashboard/services/TimeSrv';
 import { withUniqueRefIds } from '../utils/queries';
 
-import { initializeExplore, paneReducer } from './explorePane';
+import { initializeExplore, InitializeExploreOptions, paneReducer } from './explorePane';
 import { DEFAULT_RANGE, makeExplorePaneState } from './utils';
 
 //
@@ -63,10 +63,7 @@ export const setPaneState = createAction<SetPaneStateActionPayload>('explore/set
 export const clearPanes = createAction('explore/clearPanes');
 
 /**
- * Opens a new split pane. It either copies existing state of an already present pane
- * or uses values from options arg.
- *
- * TODO: this can be improved by better inferring fallback values.
+ * Ensure Explore doesn't exceed supported number of panes and initializes the new pane.
  */
 export const splitOpen = createAsyncThunk(
   'explore/splitOpen',
@@ -76,8 +73,15 @@ export const splitOpen = createAsyncThunk(
 
     const queries = options?.queries ?? (options?.query ? [options?.query] : originState?.queries || []);
 
+    Object.keys(getState().explore.panes).forEach((paneId, index) => {
+      // Only 2 panes are supported. Remove panes before create a new one.
+      if (index >= 1) {
+        dispatch(splitClose(paneId));
+      }
+    });
+
     await dispatch(
-      initializeExplore({
+      createNewSplitOpenPane({
         exploreId: requestId,
         datasource: options?.datasourceUid || originState?.datasourceInstance?.getRef(),
         queries: withUniqueRefIds(queries),
@@ -91,6 +95,19 @@ export const splitOpen = createAsyncThunk(
   }
 );
 
+/**
+ * Opens a new split pane. It either copies existing state of an already present pane
+ * or uses values from options arg.
+ *
+ * TODO: this can be improved by better inferring fallback values.
+ */
+const createNewSplitOpenPane = createAsyncThunk(
+  'explore/createNewSplitOpen',
+  async (options: InitializeExploreOptions, { dispatch }) => {
+    await dispatch(initializeExplore(options));
+  }
+);
+
 export interface NavigateToExploreDependencies {
   getDataSourceSrv: () => DataSourceSrv;
   getTimeSrv: () => TimeSrv;
@@ -215,12 +232,12 @@ export const exploreReducer = (state = initialExploreState, action: AnyAction):
     };
   }
 
-  if (splitOpen.pending.match(action)) {
+  if (createNewSplitOpenPane.pending.match(action)) {
     return {
       ...state,
       panes: {
         ...state.panes,
-        [action.meta.requestId]: initialExploreItemState,
+        [action.meta.arg.exploreId]: initialExploreItemState,
       },
     };
   }