From c10c70d951588e070a9bb7cb0b99f7bbaf137bb1 Mon Sep 17 00:00:00 2001
From: robinvrd <verdier.robin@gmail.com>
Date: Fri, 30 Oct 2026 11:19:20 +0100
Subject: [PATCH 1/2] fix: truncate long bar chart category labels

---
 docs/ui.md                                  |  2 +
 packages/data-app-react/src/ui/BarChart.css | 15 +++-
 packages/data-app-react/src/ui/BarChart.tsx |  4 +-
 tests/public-api/apps-charts.test.ts        | 84 +++++++++++++++++++++
 tests/public-api/fixtures/chart-legends.tsx | 31 ++++++++
 5 files changed, 133 insertions(+), 3 deletions(-)

diff --git a/docs/ui.md b/docs/ui.md
index 1ba62da0..ca319065 100644
--- a/docs/ui.md
+++ b/docs/ui.md
@@ -152,6 +152,8 @@ Compose the visual inside `<VisualizationWidget dataset={dataset} source={result
 so rows, loading state, evidence, and inspection come from that dataset.
 Pass ordered items with unique, nonblank IDs and finite numbers. Bar and pie
 values must be nonnegative. Use `formatValue` for domain formatting.
+Bar category labels truncate to fit their columns; hover a bar to read its full
+category name and value.
 
 Line and area charts space samples equally; include missing periods and use
 composed charts for irregular intervals. Distinguish missing observations from zero.
diff --git a/packages/data-app-react/src/ui/BarChart.css b/packages/data-app-react/src/ui/BarChart.css
index c218a5ff..49e02030 100644
--- a/packages/data-app-react/src/ui/BarChart.css
+++ b/packages/data-app-react/src/ui/BarChart.css
@@ -80,7 +80,8 @@
   justify-content: center;
   gap: var(--atbl-space-xs);
   min-height: var(--atbl-control-compact-height);
-  padding-top: 4px;
+  min-width: 0;
+  padding: 4px 4px 0;
   color: var(--atbl-muted);
 }
 .altertable-chart-item-label-row > span {
@@ -94,11 +95,23 @@
   display: inline-flex;
   align-items: center;
   gap: 4px;
+  min-width: 0;
+  max-width: 100%;
   min-height: 0;
   padding: 0;
   color: inherit;
 }
 
+.altertable-selectable-bars-label > span {
+  min-width: 0;
+  overflow: hidden;
+  text-overflow: ellipsis;
+}
+
+.altertable-selectable-bars-label > svg {
+  flex-shrink: 0;
+}
+
 .altertable-chart-item-label-row button.altertable-selectable-bars-label {
   padding: var(--atbl-space-xs) 6px;
   border: 1px solid transparent;
diff --git a/packages/data-app-react/src/ui/BarChart.tsx b/packages/data-app-react/src/ui/BarChart.tsx
index 42649767..af986d6c 100644
--- a/packages/data-app-react/src/ui/BarChart.tsx
+++ b/packages/data-app-react/src/ui/BarChart.tsx
@@ -180,7 +180,7 @@ export function BarChart<Row extends BarChartItem>({
                             }}
                             aria-label={`${item.label}: Actions`}
                           >
-                            {item.label}
+                            <span title={item.label}>{item.label}</span>
                             <AppIcon name="disclosure" size={12} />
                           </MenuButton>
                           <ExplorationActionMenu
@@ -192,7 +192,7 @@ export function BarChart<Row extends BarChartItem>({
                         </MenuTrigger>
                       ) : (
                         <span className="altertable-selectable-bars-label">
-                          {item.label}
+                          <span title={item.label}>{item.label}</span>
                         </span>
                       )}
                     </div>
diff --git a/tests/public-api/apps-charts.test.ts b/tests/public-api/apps-charts.test.ts
index fd6b56e2..517b11f1 100644
--- a/tests/public-api/apps-charts.test.ts
+++ b/tests/public-api/apps-charts.test.ts
@@ -1207,3 +1207,87 @@ test('legend controls stay separate from plot inspection', async ({ page }) => {
   await page.keyboard.press('ArrowRight');
   await expect.poll(() => tooltip.getByRole('listitem').count()).toBe(2);
 });
+
+test('long bar category labels fit their columns and retain full readings', async ({
+  page,
+}) => {
+  await page.goto('/chart-legends');
+  for (const theme of ['light', 'dark']) {
+    if (theme === 'dark')
+      await page.getByRole('button', { name: 'Switch to dark theme' }).click();
+    for (const width of [1280, 320]) {
+      await page.setViewportSize({ width, height: 900 });
+      for (const mode of ['plain', 'with actions']) {
+        const chart = page.getByRole('region', {
+          name: `Long category bars ${mode}`,
+          exact: true,
+        });
+        const labels = chart.getByTitle(/B2B|Business|International/);
+        await expect.poll(() => labels.count()).toBe(6);
+        await expect
+          .poll(async () => {
+            const bounds = await labels.evaluateAll(elements =>
+              elements.map(element => {
+                const rect = element.getBoundingClientRect();
+                return {
+                  left: rect.left,
+                  right: rect.right,
+                  width: rect.width,
+                };
+              })
+            );
+            const columns = await chart
+              .getByRole('button', { name: /: \d+ people/ })
+              .evaluateAll(elements =>
+                elements.map(element => {
+                  const rect = element.getBoundingClientRect();
+                  return { left: rect.left, right: rect.right };
+                })
+              );
+            const centers = columns.map(
+              column => (column.left + column.right) / 2
+            );
+            const halfColumn = (centers[1]! - centers[0]!) / 2;
+            return bounds.every(
+              (label, index) =>
+                label.width > 0 &&
+                label.left >= centers[index]! - halfColumn - 1 &&
+                label.right <= centers[index]! + halfColumn + 1
+            );
+          })
+          .toBe(true);
+        const last = 'B2BReactivationWithoutSpaces';
+        expect(
+          await chart.getByTitle(last, { exact: true }).evaluate(element => {
+            const style = getComputedStyle(element);
+            return (
+              element.scrollWidth > element.clientWidth &&
+              style.overflowX === 'hidden' &&
+              style.textOverflow === 'ellipsis'
+            );
+          })
+        ).toBe(true);
+        await chart
+          .getByRole('button', { name: new RegExp(`${last}: 20 people`) })
+          .hover();
+        await expect
+          .poll(() => page.getByRole('tooltip').textContent())
+          .toContain(last);
+        await page.keyboard.press('Escape');
+        if (mode === 'with actions') {
+          await chart
+            .getByRole('button', { name: `${last}: Actions`, exact: true })
+            .click();
+          await expect
+            .poll(() =>
+              page
+                .getByRole('menuitem', { name: 'Inspect', exact: true })
+                .isVisible()
+            )
+            .toBe(true);
+          await page.keyboard.press('Escape');
+        }
+      }
+    }
+  }
+});
diff --git a/tests/public-api/fixtures/chart-legends.tsx b/tests/public-api/fixtures/chart-legends.tsx
index ced37680..c53fd271 100644
--- a/tests/public-api/fixtures/chart-legends.tsx
+++ b/tests/public-api/fixtures/chart-legends.tsx
@@ -580,6 +580,37 @@ createRoot(document.getElementById('root')!).render(
           </ChartLegend>
         </Stack>
       </Example>
+      {[false, true].map(withActions => (
+        <Example
+          key={String(withActions)}
+          name={`Long category bars ${withActions ? 'with actions' : 'plain'}`}
+          description="Long category labels stay within their bar columns."
+        >
+          <BarChart
+            ariaLabel={`Long category bars ${withActions ? 'with actions' : 'plain'}`}
+            unit="people"
+            items={[
+              'B2B Preonboarding',
+              'B2B Retention',
+              'Business Development',
+              'B2B Onboarding',
+              'International After Sales',
+              'B2BReactivationWithoutSpaces',
+            ].map((label, index) => ({
+              id: String(index),
+              label,
+              value: 60 - index * 8,
+            }))}
+            itemActions={
+              withActions
+                ? () => [
+                    { id: 'inspect', label: 'Inspect', onSelect: () => {} },
+                  ]
+                : undefined
+            }
+          />
+        </Example>
+      ))}
       <Example
         name="Standalone bar"
         description="Original category input contract."

From 6430fcc98be4e6e5729cf1be48bf6b025e314a39 Mon Sep 17 00:00:00 2001
From: robinvrd <verdier.robin@gmail.com>
Date: Fri, 30 Oct 2026 11:28:15 +0100
Subject: [PATCH 2/2] chore: remove bar label documentation change

---
 docs/ui.md | 2 --
 1 file changed, 2 deletions(-)

diff --git a/docs/ui.md b/docs/ui.md
index ca319065..1ba62da0 100644
--- a/docs/ui.md
+++ b/docs/ui.md
@@ -152,8 +152,6 @@ Compose the visual inside `<VisualizationWidget dataset={dataset} source={result
 so rows, loading state, evidence, and inspection come from that dataset.
 Pass ordered items with unique, nonblank IDs and finite numbers. Bar and pie
 values must be nonnegative. Use `formatValue` for domain formatting.
-Bar category labels truncate to fit their columns; hover a bar to read its full
-category name and value.
 
 Line and area charts space samples equally; include missing periods and use
 composed charts for irregular intervals. Distinguish missing observations from zero.