(superset) 01/01: test(plugin-chart-echarts): prove user-selected plain legend type is honored (#39540)

[ru...@apache.org]

This is an automated email from the ASF dual-hosted git repository.

rusackas pushed a commit to branch test/issue-39540-legend-type-plain
in repository https://gitbox.apache.org/repos/asf/superset.git

commit df11a40ccc63d5aa1d155533aa1b654662bc6678
Author: Claude Code <no...@anthropic.com>
AuthorDate: Mon Jul 6 16:53:40 2026 -0700

    test(plugin-chart-echarts): prove user-selected plain legend type is honored (#39540)
    
    Adds regression coverage for issue #39540, where switching the legend
    type control from scroll to plain had no effect on rendered charts.
    The regression came from unconditionally forcing scroll legends for
    horizontal (top/bottom) orientations; plain legend layout support with
    an effectiveType fallback later restored the user's choice.
    
    These tests pin the fixed contract at two levels:
    
    - getLegendLayoutResult: a user-selected plain type is honored for
      horizontal legends (including many items on a wide chart, and bottom
      orientation), and a user-selected scroll type passes through
      untouched, with scroll reserved as a fallback for legends that do not
      fit the available space.
    - Timeseries transformProps: the plain selection survives end-to-end
      into echartOptions.legend.type for both top and bottom orientations
      when space allows.
    
    Co-Authored-By: Claude Fable 5 <no...@anthropic.com>
---
 .../test/Timeseries/transformProps.test.ts         | 40 ++++++++++++++++
 .../plugin-chart-echarts/test/utils/series.test.ts | 56 ++++++++++++++++++++++
 2 files changed, 96 insertions(+)

diff --git a/superset-frontend/plugins/plugin-chart-echarts/test/Timeseries/transformProps.test.ts b/superset-frontend/plugins/plugin-chart-echarts/test/Timeseries/transformProps.test.ts
index 00cc84ff11f..74c7dfd1237 100644
--- a/superset-frontend/plugins/plugin-chart-echarts/test/Timeseries/transformProps.test.ts
+++ b/superset-frontend/plugins/plugin-chart-echarts/test/Timeseries/transformProps.test.ts
@@ -938,6 +938,46 @@ describe('legend sorting', () => {
   });
 });
 
+test('honors user-selected plain legend type for top orientation when space allows (#39540)', () => {
+  // Regression test for issue #39540: switching the legend type control from
+  // scroll to plain must reach the rendered ECharts config. Horizontal legends
+  // were once unconditionally forced to scroll; scroll should be a fallback
+  // reserved for legends that do not fit the available space.
+  const chartProps = createTestChartProps({
+    formData: {
+      ...formData,
+      legendType: LegendType.Plain,
+      legendOrientation: LegendOrientation.Top,
+      showLegend: true,
+    },
+  });
+
+  const { legend } = transformProps(chartProps).echartOptions as {
+    legend: { show?: boolean; type?: LegendType };
+  };
+
+  expect(legend.show).toBe(true);
+  expect(legend.type).toBe(LegendType.Plain);
+});
+
+test('honors user-selected plain legend type for bottom orientation when space allows (#39540)', () => {
+  const chartProps = createTestChartProps({
+    formData: {
+      ...formData,
+      legendType: LegendType.Plain,
+      legendOrientation: LegendOrientation.Bottom,
+      showLegend: true,
+    },
+  });
+
+  const { legend } = transformProps(chartProps).echartOptions as {
+    legend: { show?: boolean; type?: LegendType };
+  };
+
+  expect(legend.show).toBe(true);
+  expect(legend.type).toBe(LegendType.Plain);
+});
+
 const timeCompareFormData: SqlaFormData = {
   colorScheme: 'bnbColors',
   datasource: '3__table',
diff --git a/superset-frontend/plugins/plugin-chart-echarts/test/utils/series.test.ts b/superset-frontend/plugins/plugin-chart-echarts/test/utils/series.test.ts
index 62489ee6b02..d0ae93f80c0 100644
--- a/superset-frontend/plugins/plugin-chart-echarts/test/utils/series.test.ts
+++ b/superset-frontend/plugins/plugin-chart-echarts/test/utils/series.test.ts
@@ -993,6 +993,62 @@ test('getLegendLayoutResult keeps plain horizontal legends when they fit within
   });
 });
 
+test('getLegendLayoutResult honors user-selected plain type for many horizontal legend items given ample width (#39540)', () => {
+  // Regression contract for issue #39540: a legend with enough items to be
+  // scrollable must still honor a user-selected plain type when the chart is
+  // wide enough, instead of being unconditionally forced to scroll.
+  const layout = getLegendLayoutResult({
+    chartHeight: 600,
+    chartWidth: 1600,
+    legendItems: Array.from({ length: 10 }, (_, i) => `Series ${i + 1}`),
+    legendMargin: null,
+    orientation: LegendOrientation.Top,
+    show: true,
+    theme,
+    type: LegendType.Plain,
+  });
+
+  expect(layout.effectiveType).toBe(LegendType.Plain);
+  expect(layout.effectiveMargin).toBeGreaterThanOrEqual(
+    defaultLegendPadding[LegendOrientation.Top],
+  );
+});
+
+test('getLegendLayoutResult keeps user-selected plain type for bottom-oriented legends when space allows', () => {
+  expect(
+    getLegendLayoutResult({
+      chartHeight: 400,
+      chartWidth: 800,
+      legendItems: ['Alpha', 'Beta', 'Gamma', 'Delta'],
+      legendMargin: null,
+      orientation: LegendOrientation.Bottom,
+      show: true,
+      theme,
+      type: LegendType.Plain,
+    }),
+  ).toEqual({
+    effectiveMargin: defaultLegendPadding[LegendOrientation.Bottom],
+    effectiveType: LegendType.Plain,
+  });
+});
+
+test('getLegendLayoutResult passes a user-selected scroll type through untouched', () => {
+  expect(
+    getLegendLayoutResult({
+      chartHeight: 400,
+      chartWidth: 800,
+      legendItems: ['Alpha', 'Beta'],
+      legendMargin: null,
+      orientation: LegendOrientation.Top,
+      show: true,
+      theme,
+      type: LegendType.Scroll,
+    }),
+  ).toEqual({
+    effectiveType: LegendType.Scroll,
+  });
+});
+
 test('getLegendLayoutResult adds extra margin for wrapped plain horizontal legends', () => {
   const layout = getLegendLayoutResult({
     chartHeight: 400,