chore: updated the types

frontend/src/container/DashboardContainer/visualization/charts/ChartWrapper/ChartWrapper.tsx

@@ -1,4 +1,4 @@
-import { useCallback, useRef } from 'react';
+import { useCallback, useMemo, useRef } from 'react';
 import ChartLayout from 'container/DashboardContainer/visualization/layout/ChartLayout/ChartLayout';
 import Legend from 'lib/uPlotV2/components/Legend/Legend';
 import {
@@ -30,6 +30,7 @@ export default function ChartWrapper({
 	onDestroy = noop,
 	children,
 	layoutChildren,
+	yAxisUnit,
 	customTooltip,
 	pinnedTooltipElement,
 	'data-testid': testId,
@@ -62,6 +63,13 @@ export default function ChartWrapper({
 		[customTooltip],
 	);
 
+	const syncMetadata = useMemo(
+		() => ({
+			yAxisUnit,
+		}),
+		[yAxisUnit],
+	);
+
 	return (
 		<PlotContextProvider>
 			<ChartLayout
@@ -99,6 +107,7 @@ export default function ChartWrapper({
 									averageLegendWidth + TOOLTIP_WIDTH_PADDING,
 								)}
 								syncKey={syncKey}
+								syncMetadata={syncMetadata}
 								render={renderTooltipCallback}
 								pinnedTooltipElement={pinnedTooltipElement}
 							/>

frontend/src/container/DashboardContainer/visualization/charts/Histogram/Histogram.tsx

@@ -24,13 +24,12 @@ export default function Histogram(props: HistogramChartProps): JSX.Element {
 			}
 			const tooltipProps: HistogramTooltipProps = {
 				...props,
-				timezone: rest.timezone,
 				yAxisUnit: rest.yAxisUnit,
 				decimalPrecision: rest.decimalPrecision,
 			};
 			return <HistogramTooltip {...tooltipProps} />;
 		},
-		[customTooltip, rest.timezone, rest.yAxisUnit, rest.decimalPrecision],
+		[customTooltip, rest.yAxisUnit, rest.decimalPrecision],
 	);
 
 	return (

frontend/src/container/DashboardContainer/visualization/charts/types.ts

@@ -12,10 +12,7 @@ interface BaseChartProps {
 	height: number;
 	showTooltip?: boolean;
 	showLegend?: boolean;
-	timezone?: Timezone;
 	canPinTooltip?: boolean;
-	yAxisUnit?: string;
-	decimalPrecision?: PrecisionOption;
 	pinnedTooltipElement?: (clickData: TooltipClickData) => React.ReactNode;
 	customTooltip?: (props: TooltipRenderArgs) => React.ReactNode;
 	'data-testid'?: string;
@@ -32,18 +29,31 @@ interface UPlotBasedChartProps {
 	layoutChildren?: React.ReactNode;
 }
 
+interface UPlotChartDataProps {
+	yAxisUnit?: string;
+	decimalPrecision?: PrecisionOption;
+}
+
 export interface TimeSeriesChartProps
 	extends BaseChartProps,
-		UPlotBasedChartProps {}
+		UPlotBasedChartProps,
+		UPlotChartDataProps {
+	timezone?: Timezone;
+}
 
 export interface HistogramChartProps
 	extends BaseChartProps,
-		UPlotBasedChartProps {
+		UPlotBasedChartProps,
+		UPlotChartDataProps {
 	isQueriesMerged?: boolean;
 }
 
-export interface BarChartProps extends BaseChartProps, UPlotBasedChartProps {
+export interface BarChartProps
+	extends BaseChartProps,
+		UPlotBasedChartProps,
+		UPlotChartDataProps {
 	isStackedBarChart?: boolean;
+	timezone?: Timezone;
 }
 
 export type ChartProps =

frontend/src/container/DashboardContainer/visualization/panels/BarPanel/BarPanel.tsx

@@ -123,13 +123,13 @@ function BarPanel(props: PanelWrapperProps): JSX.Element {
 					}}
 					plotRef={onPlotRef}
 					onDestroy={onPlotDestroy}
-					yAxisUnit={widget.yAxisUnit}
-					decimalPrecision={widget.decimalPrecision}
 					data={chartData as uPlot.AlignedData}
 					width={containerDimensions.width}
 					height={containerDimensions.height}
 					layoutChildren={layoutChildren}
 					isStackedBarChart={widget.stackedBarChart ?? false}
+					yAxisUnit={widget.yAxisUnit}
+					decimalPrecision={widget.decimalPrecision}
 					timezone={timezone}
 				>
 					<ContextMenu

frontend/src/container/DashboardContainer/visualization/panels/HistogramPanel/HistogramPanel.tsx

@@ -4,7 +4,6 @@ import { useIsDarkMode } from 'hooks/useDarkMode';
 import { useResizeObserver } from 'hooks/useDimensions';
 import { LegendPosition } from 'lib/uPlotV2/components/types';
 import { DashboardCursorSync } from 'lib/uPlotV2/plugins/TooltipPlugin/types';
-import { useTimezone } from 'providers/Timezone';
 import uPlot from 'uplot';
 
 import Histogram from '../../charts/Histogram/Histogram';
@@ -29,7 +28,6 @@ function HistogramPanel(props: PanelWrapperProps): JSX.Element {
 	const containerDimensions = useResizeObserver(graphRef);
 
 	const isDarkMode = useIsDarkMode();
-	const { timezone } = useTimezone();
 
 	const config = useMemo(() => {
 		return prepareHistogramPanelConfig({
@@ -92,11 +90,10 @@ function HistogramPanel(props: PanelWrapperProps): JSX.Element {
 					onDestroy={(): void => {
 						uPlotRef.current = null;
 					}}
-					isQueriesMerged={widget.mergeAllActiveQueries}
 					yAxisUnit={widget.yAxisUnit}
 					decimalPrecision={widget.decimalPrecision}
+					isQueriesMerged={widget.mergeAllActiveQueries}
 					syncMode={DashboardCursorSync.Crosshair}
-					timezone={timezone}
 					data={chartData as uPlot.AlignedData}
 					width={containerDimensions.width}
 					height={containerDimensions.height}

frontend/src/container/DashboardContainer/visualization/panels/HistogramPanel/__tests__/HistogramPanel.test.tsx

@@ -48,8 +48,8 @@ jest.mock(
 					{JSON.stringify({
 						legendPosition: props.legendConfig?.position,
 						isQueriesMerged: props.isQueriesMerged,
-						yAxisUnit: props.yAxisUnit,
-						decimalPrecision: props.decimalPrecision,
+						yAxisUnit: props?.yAxisUnit,
+						decimalPrecision: props?.decimalPrecision,
 					})}
 				</div>
 				{props.layoutChildren}

frontend/src/container/DashboardContainer/visualization/panels/TimeSeriesPanel/TimeSeriesPanel.tsx

@@ -6,6 +6,7 @@ import { PanelWrapperProps } from 'container/PanelWrapper/panelWrapper.types';
 import { useIsDarkMode } from 'hooks/useDarkMode';
 import { useResizeObserver } from 'hooks/useDimensions';
 import { LegendPosition } from 'lib/uPlotV2/components/types';
+import { DashboardCursorSync } from 'lib/uPlotV2/plugins/TooltipPlugin/types';
 import { ContextMenu } from 'periscope/components/ContextMenu';
 import { useTimezone } from 'providers/Timezone';
 import uPlot from 'uplot';
@@ -112,10 +113,13 @@ function TimeSeriesPanel(props: PanelWrapperProps): JSX.Element {
 					legendConfig={{
 						position: widget?.legendPosition ?? LegendPosition.BOTTOM,
 					}}
+					timezone={timezone}
 					yAxisUnit={widget.yAxisUnit}
 					decimalPrecision={widget.decimalPrecision}
-					timezone={timezone}
 					data={chartData as uPlot.AlignedData}
+					syncMode={
+						isFullViewMode ? DashboardCursorSync.None : DashboardCursorSync.Crosshair
+					}
 					width={containerDimensions.width}
 					height={containerDimensions.height}
 					layoutChildren={layoutChildren}

frontend/src/lib/uPlotV2/components/types.ts

@@ -62,10 +62,10 @@ export interface TooltipRenderArgs {
 
 export interface BaseTooltipProps {
 	showTooltipHeader?: boolean;
-	timezone?: Timezone;
 	yAxisUnit?: string;
 	decimalPrecision?: PrecisionOption;
 	content?: TooltipContentItem[];
+	timezone?: Timezone;
 }
 
 export interface TimeSeriesTooltipProps

frontend/src/lib/uPlotV2/plugins/TooltipPlugin/TooltipPlugin.tsx

@@ -4,6 +4,7 @@ import cx from 'classnames';
 import { getFocusedSeriesAtPosition } from 'lib/uPlotLib/plugins/onClickPlugin';
 import uPlot from 'uplot';
 
+import { syncCursorRegistry } from './syncCursorRegistry';
 import {
 	createInitialControllerState,
 	createSetCursorHandler,
@@ -40,6 +41,7 @@ export default function TooltipPlugin({
 	maxHeight = 600,
 	syncMode = DashboardCursorSync.None,
 	syncKey = '_tooltip_sync_global_',
+	syncMetadata,
 	pinnedTooltipElement,
 	canPinTooltip = false,
 }: TooltipPluginProps): JSX.Element | null {
@@ -100,7 +102,29 @@ export default function TooltipPlugin({
 		// crosshair / tooltip can follow the dashboard-wide cursor.
 		if (syncMode !== DashboardCursorSync.None && config.scales[0]?.props.time) {
 			config.setCursor({
-				sync: { key: syncKey, scales: ['x', null] },
+				sync: { key: syncKey, scales: ['x', 'y'] },
+			});
+
+			// Show the horizontal crosshair only when the receiving panel shares
+			// the same y-axis unit as the source panel. When this panel is the
+			// source (cursor.event != null) the line is always shown and this
+			// panel's metadata is written to the registry so receivers can read it.
+			config.addHook('setCursor', (u: uPlot): void => {
+				const yCursorEl = u.root.querySelector<HTMLElement>('.u-cursor-y');
+				if (!yCursorEl) {
+					return;
+				}
+
+				if (u.cursor.event != null) {
+					// This panel is the source — publish metadata and always show line.
+					syncCursorRegistry.setMetadata(syncKey, syncMetadata);
+					yCursorEl.style.display = '';
+				} else {
+					// This panel is receiving sync — show only if units match.
+					const sourceMeta = syncCursorRegistry.getMetadata(syncKey);
+					yCursorEl.style.display =
+						sourceMeta?.yAxisUnit === syncMetadata?.yAxisUnit ? '' : 'none';
+				}
 			});
 		}
 

frontend/src/lib/uPlotV2/plugins/TooltipPlugin/syncCursorRegistry.ts

@@ -0,0 +1,24 @@
+import type { TooltipSyncMetadata } from './types';
+
+/**
+ * Module-level registry that tracks the metadata of the panel currently
+ * acting as the cursor source (the one being hovered) per sync group.
+ *
+ * uPlot fires the source panel's setCursor hook before broadcasting to
+ * receivers, so the registry is always populated before receivers read it.
+ *
+ * Receivers use this to make decisions such as:
+ * - Whether to show the horizontal crosshair line (matching yAxisUnit)
+ * - Future: what to render inside the tooltip (matching groupBy, etc.)
+ */
+const metadataBySyncKey = new Map<string, TooltipSyncMetadata | undefined>();
+
+export const syncCursorRegistry = {
+	setMetadata(syncKey: string, metadata: TooltipSyncMetadata | undefined): void {
+		metadataBySyncKey.set(syncKey, metadata);
+	},
+
+	getMetadata(syncKey: string): TooltipSyncMetadata | undefined {
+		return metadataBySyncKey.get(syncKey);
+	},
+};

frontend/src/lib/uPlotV2/plugins/TooltipPlugin/types.ts

@@ -34,11 +34,16 @@ export interface TooltipLayoutInfo {
 	height: number;
 }
 
+export interface TooltipSyncMetadata {
+	yAxisUnit?: string;
+}
+
 export interface TooltipPluginProps {
 	config: UPlotConfigBuilder;
 	canPinTooltip?: boolean;
 	syncMode?: DashboardCursorSync;
 	syncKey?: string;
+	syncMetadata?: TooltipSyncMetadata;
 	render: (args: TooltipRenderArgs) => ReactNode;
 	pinnedTooltipElement?: (clickData: TooltipClickData) => ReactNode;
 	maxWidth?: number;

frontend/src/lib/uPlotV2/plugins/__tests__/TooltipPlugin.test.ts

@@ -516,7 +516,7 @@ describe('TooltipPlugin', () => {
 			);
 
 			expect(setCursorSpy).toHaveBeenCalledWith({
-				sync: { key: 'dashboard-sync', scales: ['x', null] },
+				sync: { key: 'dashboard-sync', scales: ['x', 'y'] },
 			});
 		});