[charts] Fix tooltip with horizontal layout

packages/x-charts/src/ChartsTooltip/ChartsAxisTooltipContent.tsx

@@ -56,7 +56,7 @@ function ChartsAxisTooltipContent(props: {
 }) {
   const { content, contentProps, axisData, sx, classes } = props;
 
-  const isXaxis = (axisData.x && axisData.x.index) !== undefined;
+  const isXaxis = axisData.x && axisData.x.index !== -1;
 
   const dataIndex = isXaxis ? axisData.x && axisData.x.index : axisData.y && axisData.y.index;
   const axisValue = isXaxis ? axisData.x && axisData.x.value : axisData.y && axisData.y.value;

packages/x-charts/src/ChartsTooltip/contentDIsplayed.test.tsx

@@ -0,0 +1,251 @@
+import * as React from 'react';
+import { expect } from 'chai';
+import { createRenderer, fireEvent } from '@mui/internal-test-utils';
+import { BarChart } from '@mui/x-charts/BarChart';
+import { firePointerEvent } from '../tests/firePointerEvent';
+
+const config = {
+  dataset: [
+    { x: 'A', v1: 4, v2: 2 },
+    { x: 'B', v1: 1, v2: 1 },
+  ],
+  margin: { top: 0, left: 0, bottom: 0, right: 0 },
+  width: 400,
+  height: 400,
+};
+
+// Plot as follow to simplify click position
+//
+// | X
+// | X
+// | X X
+// | X X X X
+// ---A---B-
+
+const isJSDOM = /jsdom/.test(window.navigator.userAgent);
+
+describe('ChartsTooltip', () => {
+  const { render } = createRenderer();
+
+  describe('axis trigger', () => {
+    it('should show right values with vertical layout', function test() {
+      if (isJSDOM) {
+        // can't do Pointer event with JSDom https://github.com/jsdom/jsdom/issues/2527
+        this.skip();
+      }
+
+      render(
+        <div
+          style={{
+            margin: -8, // Removes the body default margins
+            width: 400,
+            height: 400,
+          }}
+        >
+          <BarChart
+            {...config}
+            series={[
+              { dataKey: 'v1', id: 's1', label: 'S1' },
+              { dataKey: 'v2', id: 's2', label: 'S2' },
+            ]}
+            xAxis={[{ scaleType: 'band', dataKey: 'x' }]}
+          />
+        </div>,
+      );
+      const svg = document.querySelector<HTMLElement>('svg')!;
+
+      firePointerEvent(svg, 'pointermove', {
+        clientX: 198,
+        clientY: 60,
+      });
+
+      let cells = document.querySelectorAll<HTMLElement>('.MuiChartsTooltip-root td');
+      expect([...cells].map((cell) => cell.textContent)).to.deep.equal([
+        // Header
+        'A',
+        // First row
+        '', // mark
+        'S1', // label
+        '4', // value
+        // Second row
+        '',
+        'S2',
+        '2',
+      ]);
+
+      firePointerEvent(svg, 'pointermove', {
+        clientX: 201,
+        clientY: 60,
+      });
+
+      cells = document.querySelectorAll<HTMLElement>('.MuiChartsTooltip-root td');
+      expect([...cells].map((cell) => cell.textContent)).to.deep.equal([
+        // Header
+        'B',
+        // First row
+        '',
+        'S1',
+        '1',
+        // Second row
+        '',
+        'S2',
+        '1',
+      ]);
+    });
+
+    it('should show right values with horizontal layout', function test() {
+      if (isJSDOM) {
+        // can't do Pointer event with JSDom https://github.com/jsdom/jsdom/issues/2527
+        this.skip();
+      }
+
+      render(
+        <div
+          style={{
+            margin: -8, // Removes the body default margins
+            width: 400,
+            height: 400,
+          }}
+        >
+          <BarChart
+            {...config}
+            layout="horizontal"
+            series={[
+              { dataKey: 'v1', id: 's1', label: 'S1' },
+              { dataKey: 'v2', id: 's2', label: 'S2' },
+            ]}
+            yAxis={[{ scaleType: 'band', dataKey: 'x' }]}
+          />
+        </div>,
+      );
+      const svg = document.querySelector<HTMLElement>('svg')!;
+
+      firePointerEvent(svg, 'pointermove', {
+        clientX: 150,
+        clientY: 60,
+      });
+
+      let cells = document.querySelectorAll<HTMLElement>('.MuiChartsTooltip-root td');
+      expect([...cells].map((cell) => cell.textContent)).to.deep.equal([
+        // Header
+        'A',
+        // First row
+        '',
+        'S1',
+        '4',
+        // Second row
+        '',
+        'S2',
+        '2',
+      ]);
+
+      firePointerEvent(svg, 'pointermove', {
+        clientX: 150,
+        clientY: 220,
+      });
+
+      cells = document.querySelectorAll<HTMLElement>('.MuiChartsTooltip-root td');
+      expect([...cells].map((cell) => cell.textContent)).to.deep.equal([
+        // Header
+        'B',
+        // First row
+        '',
+        'S1',
+        '1',
+        // Second row
+        '',
+        'S2',
+        '1',
+      ]);
+    });
+  });
+
+  describe('item trigger', () => {
+    it('should show right values with vertical layout', function test() {
+      if (isJSDOM) {
+        // can't do Pointer event with JSDom https://github.com/jsdom/jsdom/issues/2527
+        this.skip();
+      }
+
+      render(
+        <div
+          style={{
+            margin: -8, // Removes the body default margins
+            width: 400,
+            height: 400,
+          }}
+        >
+          <BarChart
+            {...config}
+            series={[
+              { dataKey: 'v1', id: 's1', label: 'S1' },
+              { dataKey: 'v2', id: 's2', label: 'S2' },
+            ]}
+            xAxis={[{ scaleType: 'band', dataKey: 'x' }]}
+            tooltip={{ trigger: 'item' }}
+          />
+        </div>,
+      );
+      const svg = document.querySelector<HTMLElement>('svg')!;
+      const rectangles = document.querySelectorAll<HTMLElement>('rect');
+
+      fireEvent.pointerEnter(rectangles[0]);
+
+      firePointerEvent(svg, 'pointermove', {
+        clientX: 150,
+        clientY: 60,
+      }); // Only to set the tooltip position
+
+      let cells = document.querySelectorAll<HTMLElement>('.MuiChartsTooltip-root td');
+      expect([...cells].map((cell) => cell.textContent)).to.deep.equal(['', 'S1', '4']);
+
+      fireEvent.pointerEnter(rectangles[3]);
+      cells = document.querySelectorAll<HTMLElement>('.MuiChartsTooltip-root td');
+      expect([...cells].map((cell) => cell.textContent)).to.deep.equal(['', 'S2', '1']);
+    });
+
+    it('should show right values with horizontal layout', function test() {
+      if (isJSDOM) {
+        // can't do Pointer event with JSDom https://github.com/jsdom/jsdom/issues/2527
+        this.skip();
+      }
+
+      render(
+        <div
+          style={{
+            margin: -8, // Removes the body default margins
+            width: 400,
+            height: 400,
+          }}
+        >
+          <BarChart
+            {...config}
+            series={[
+              { dataKey: 'v1', id: 's1', label: 'S1' },
+              { dataKey: 'v2', id: 's2', label: 'S2' },
+            ]}
+            layout="horizontal"
+            yAxis={[{ scaleType: 'band', dataKey: 'x' }]}
+            tooltip={{ trigger: 'item' }}
+          />
+        </div>,
+      );
+      const svg = document.querySelector<HTMLElement>('svg')!;
+      const rectangles = document.querySelectorAll<HTMLElement>('rect');
+
+      fireEvent.pointerEnter(rectangles[0]);
+
+      firePointerEvent(svg, 'pointermove', {
+        clientX: 150,
+        clientY: 60,
+      }); // Only to set the tooltip position
+
+      let cells = document.querySelectorAll<HTMLElement>('.MuiChartsTooltip-root td');
+      expect([...cells].map((cell) => cell.textContent)).to.deep.equal(['', 'S1', '4']);
+
+      fireEvent.pointerEnter(rectangles[3]);
+      cells = document.querySelectorAll<HTMLElement>('.MuiChartsTooltip-root td');
+      expect([...cells].map((cell) => cell.textContent)).to.deep.equal(['', 'S2', '1']);
+    });
+  });
+});

packages/x-charts/src/context/InteractionProvider.tsx

@@ -10,11 +10,13 @@ export type ItemInteractionData<T extends ChartSeriesType> = ChartItemIdentifier
 export type AxisInteractionData = {
   x: null | {
     value: number | Date | string;
-    index?: number;
+    // Set to -1 if no index.
+    index: number;
   };
   y: null | {
     value: number | Date | string;
-    index?: number;
+    // Set to -1 if no index.
+    index: number;
   };
 };
 

packages/x-charts/src/hooks/useAxisEvents.ts

@@ -39,7 +39,7 @@ export const useAxisEvents = (disableAxisListener: boolean) => {
         const value = scale.invert(mouseValue);
 
         if (axisData === undefined) {
-          return { value };
+          return { value, index: -1 };
         }
 
         const valueAsNumber = getAsANumber(value);