fix: dynamic variables options load first time (#10361)

frontend/src/container/DashboardContainer/DashboardVariablesSelection/DashboardVariableSelection.tsx

@@ -34,6 +34,9 @@ function DashboardVariableSelection(): JSX.Element | null {
 	const sortedVariablesArray = useDashboardVariablesSelector(
 		(state) => state.sortedVariablesArray,
 	);
+	const dynamicVariableOrder = useDashboardVariablesSelector(
+		(state) => state.dynamicVariableOrder,
+	);
 	const dependencyData = useDashboardVariablesSelector(
 		(state) => state.dependencyData,
 	);
@@ -52,10 +55,11 @@ function DashboardVariableSelection(): JSX.Element | null {
 	}, [getUrlVariables, updateUrlVariable, dashboardVariables]);
 
 	// Memoize the order key to avoid unnecessary triggers
-	const dependencyOrderKey = useMemo(
-		() => dependencyData?.order?.join(',') ?? '',
-		[dependencyData?.order],
-	);
+	const variableOrderKey = useMemo(() => {
+		const queryVariableOrderKey = dependencyData?.order?.join(',') ?? '';
+		const dynamicVariableOrderKey = dynamicVariableOrder?.join(',') ?? '';
+		return `${queryVariableOrderKey}|${dynamicVariableOrderKey}`;
+	}, [dependencyData?.order, dynamicVariableOrder]);
 
 	// Initialize fetch store then start a new fetch cycle.
 	// Runs on dependency order changes, and time range changes.
@@ -66,7 +70,7 @@ function DashboardVariableSelection(): JSX.Element | null {
 		initializeVariableFetchStore(allVariableNames);
 		enqueueFetchOfAllVariables();
 		// eslint-disable-next-line react-hooks/exhaustive-deps
-	}, [dependencyOrderKey, minTime, maxTime]);
+	}, [variableOrderKey, minTime, maxTime]);
 
 	// Performance optimization: For dynamic variables with allSelected=true, we don't store
 	// individual values in localStorage since we can always derive them from available options.

frontend/src/container/DashboardContainer/DashboardVariablesSelection/__test__/DashboardVariableSelection.test.tsx

@@ -0,0 +1,203 @@
+/* eslint-disable sonarjs/no-duplicate-string */
+import { act, render } from '@testing-library/react';
+import {
+	dashboardVariablesStore,
+	setDashboardVariablesStore,
+	updateDashboardVariablesStore,
+} from 'providers/Dashboard/store/dashboardVariables/dashboardVariablesStore';
+import {
+	IDashboardVariables,
+	IDashboardVariablesStoreState,
+} from 'providers/Dashboard/store/dashboardVariables/dashboardVariablesStoreTypes';
+import {
+	enqueueFetchOfAllVariables,
+	initializeVariableFetchStore,
+} from 'providers/Dashboard/store/variableFetchStore';
+import { IDashboardVariable } from 'types/api/dashboard/getAll';
+
+import DashboardVariableSelection from '../DashboardVariableSelection';
+
+// Mock providers/Dashboard/Dashboard
+const mockSetSelectedDashboard = jest.fn();
+const mockUpdateLocalStorageDashboardVariables = jest.fn();
+jest.mock('providers/Dashboard/Dashboard', () => ({
+	useDashboard: (): Record<string, unknown> => ({
+		setSelectedDashboard: mockSetSelectedDashboard,
+		updateLocalStorageDashboardVariables: mockUpdateLocalStorageDashboardVariables,
+	}),
+}));
+
+// Mock hooks/dashboard/useVariablesFromUrl
+const mockUpdateUrlVariable = jest.fn();
+const mockGetUrlVariables = jest.fn().mockReturnValue({});
+jest.mock('hooks/dashboard/useVariablesFromUrl', () => ({
+	__esModule: true,
+	default: (): Record<string, unknown> => ({
+		updateUrlVariable: mockUpdateUrlVariable,
+		getUrlVariables: mockGetUrlVariables,
+	}),
+}));
+
+// Mock variableFetchStore functions
+jest.mock('providers/Dashboard/store/variableFetchStore', () => ({
+	initializeVariableFetchStore: jest.fn(),
+	enqueueFetchOfAllVariables: jest.fn(),
+	enqueueDescendantsOfVariable: jest.fn(),
+}));
+
+// Mock initializeDefaultVariables
+jest.mock('providers/Dashboard/initializeDefaultVariables', () => ({
+	initializeDefaultVariables: jest.fn(),
+}));
+
+// Mock react-redux useSelector for globalTime
+jest.mock('react-redux', () => ({
+	...jest.requireActual('react-redux'),
+	useSelector: jest.fn().mockReturnValue({ minTime: 1000, maxTime: 2000 }),
+}));
+
+// Mock VariableItem to avoid rendering complexity
+jest.mock('../VariableItem', () => ({
+	__esModule: true,
+	default: (): JSX.Element => <div data-testid="variable-item" />,
+}));
+
+function createVariable(
+	overrides: Partial<IDashboardVariable> = {},
+): IDashboardVariable {
+	return {
+		id: 'test-id',
+		name: 'test-var',
+		description: '',
+		type: 'QUERY',
+		sort: 'DISABLED',
+		showALLOption: false,
+		multiSelect: false,
+		order: 0,
+		...overrides,
+	};
+}
+
+function resetStore(): void {
+	dashboardVariablesStore.set(() => ({
+		dashboardId: '',
+		variables: {},
+		sortedVariablesArray: [],
+		dependencyData: null,
+		variableTypes: {},
+		dynamicVariableOrder: [],
+	}));
+}
+
+describe('DashboardVariableSelection', () => {
+	beforeEach(() => {
+		resetStore();
+		jest.clearAllMocks();
+	});
+
+	it('should call initializeVariableFetchStore and enqueueFetchOfAllVariables on mount', () => {
+		const variables: IDashboardVariables = {
+			env: createVariable({ name: 'env', type: 'QUERY', order: 0 }),
+		};
+
+		setDashboardVariablesStore({ dashboardId: 'dash-1', variables });
+
+		render(<DashboardVariableSelection />);
+
+		expect(initializeVariableFetchStore).toHaveBeenCalledWith(['env']);
+		expect(enqueueFetchOfAllVariables).toHaveBeenCalled();
+	});
+
+	it('should re-trigger fetch cycle when dynamicVariableOrder changes', () => {
+		const variables: IDashboardVariables = {
+			env: createVariable({ name: 'env', type: 'QUERY', order: 0 }),
+		};
+
+		setDashboardVariablesStore({ dashboardId: 'dash-1', variables });
+
+		render(<DashboardVariableSelection />);
+
+		// Clear mocks after initial render
+		(initializeVariableFetchStore as jest.Mock).mockClear();
+		(enqueueFetchOfAllVariables as jest.Mock).mockClear();
+
+		// Add a DYNAMIC variable which changes dynamicVariableOrder
+		act(() => {
+			updateDashboardVariablesStore({
+				dashboardId: 'dash-1',
+				variables: {
+					env: createVariable({ name: 'env', type: 'QUERY', order: 0 }),
+					dyn1: createVariable({ name: 'dyn1', type: 'DYNAMIC', order: 1 }),
+				},
+			});
+		});
+
+		expect(initializeVariableFetchStore).toHaveBeenCalledWith(
+			expect.arrayContaining(['env', 'dyn1']),
+		);
+		expect(enqueueFetchOfAllVariables).toHaveBeenCalled();
+	});
+
+	it('should re-trigger fetch cycle when a dynamic variable is removed', () => {
+		const variables: IDashboardVariables = {
+			env: createVariable({ name: 'env', type: 'QUERY', order: 0 }),
+			dyn1: createVariable({ name: 'dyn1', type: 'DYNAMIC', order: 1 }),
+			dyn2: createVariable({ name: 'dyn2', type: 'DYNAMIC', order: 2 }),
+		};
+
+		setDashboardVariablesStore({ dashboardId: 'dash-1', variables });
+
+		render(<DashboardVariableSelection />);
+
+		(initializeVariableFetchStore as jest.Mock).mockClear();
+		(enqueueFetchOfAllVariables as jest.Mock).mockClear();
+
+		// Remove dyn2, changing dynamicVariableOrder from ['dyn1','dyn2'] to ['dyn1']
+		act(() => {
+			updateDashboardVariablesStore({
+				dashboardId: 'dash-1',
+				variables: {
+					env: createVariable({ name: 'env', type: 'QUERY', order: 0 }),
+					dyn1: createVariable({ name: 'dyn1', type: 'DYNAMIC', order: 1 }),
+				},
+			});
+		});
+
+		expect(initializeVariableFetchStore).toHaveBeenCalledWith(['env', 'dyn1']);
+		expect(enqueueFetchOfAllVariables).toHaveBeenCalled();
+	});
+
+	it('should NOT re-trigger fetch cycle when dynamicVariableOrder stays the same', () => {
+		const variables: IDashboardVariables = {
+			env: createVariable({ name: 'env', type: 'QUERY', order: 0 }),
+			dyn1: createVariable({ name: 'dyn1', type: 'DYNAMIC', order: 1 }),
+		};
+
+		setDashboardVariablesStore({ dashboardId: 'dash-1', variables });
+
+		render(<DashboardVariableSelection />);
+
+		(initializeVariableFetchStore as jest.Mock).mockClear();
+		(enqueueFetchOfAllVariables as jest.Mock).mockClear();
+
+		// Update a non-dynamic variable's selectedValue — dynamicVariableOrder unchanged
+		act(() => {
+			const snapshot = dashboardVariablesStore.getSnapshot();
+			dashboardVariablesStore.set(
+				(): IDashboardVariablesStoreState => ({
+					...snapshot,
+					variables: {
+						...snapshot.variables,
+						env: {
+							...snapshot.variables.env,
+							selectedValue: 'production',
+						},
+					},
+				}),
+			);
+		});
+
+		expect(initializeVariableFetchStore).not.toHaveBeenCalled();
+		expect(enqueueFetchOfAllVariables).not.toHaveBeenCalled();
+	});
+});