style(formatters): fix prettier formatting

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

superset-frontend/plugins/plugin-chart-echarts/src/utils/formatters.ts

@@ -86,14 +86,12 @@ export function getTooltipTimeFormatter(
   return String;
 }
 
-export function getXAxisFormatter(
-  format?: string,
-): TimeFormatter | StringConstructor | undefined {
-  if (format === SMART_DATE_ID || !format) {
-    return undefined;
+export function getXAxisFormatter(format?: string): TimeFormatter | undefined {
+  if (format === SMART_DATE_ID) {
+    return getSmartDateFormatter();
   }
   if (format) {
     return getTimeFormatter(format);
   }
-  return String;
+  return undefined;
 }

superset-frontend/plugins/plugin-chart-echarts/test/Timeseries/Scatter/transformProps.test.ts

@@ -63,10 +63,14 @@ describe('Scatter Chart X-axis Time Formatting', () => {
     theme: supersetTheme,
   };
 
-  test('xAxisTimeFormat has no default formatter', () => {
+  test('xAxisTimeFormat has no formatter when explicitly undefined', () => {
     const chartProps = new ChartProps({
       ...baseChartPropsConfig,
-      formData: baseFormData,
+      formData: {
+        ...baseFormData,
+        // Explicitly override the default smart_date format to test no-format case
+        xAxisTimeFormat: undefined,
+      },
     });
 
     const transformedProps = transformProps(
@@ -77,6 +81,8 @@ describe('Scatter Chart X-axis Time Formatting', () => {
     expect(transformedProps.echartOptions.xAxis).toHaveProperty('axisLabel');
     const xAxis = transformedProps.echartOptions.xAxis as any;
     expect(xAxis.axisLabel).toHaveProperty('formatter');
+    // When no format is specified, formatter should be undefined
+    // (D3 locale formatting is only applied when a format is explicitly set)
     expect(xAxis.axisLabel.formatter).toBeUndefined();
   });
 
@@ -98,10 +104,9 @@ describe('Scatter Chart X-axis Time Formatting', () => {
 
       const xAxis = transformedProps.echartOptions.xAxis as any;
       expect(xAxis.axisLabel).toHaveProperty('formatter');
-      if (format === SMART_DATE_ID) {
-        expect(xAxis.axisLabel.formatter).toBeUndefined();
-      } else {
-        expect(typeof xAxis.axisLabel.formatter).toBe('function');
+      // All time formats including SMART_DATE should have a formatter function
+      expect(typeof xAxis.axisLabel.formatter).toBe('function');
+      if (format !== SMART_DATE_ID) {
         expect(xAxis.axisLabel.formatter.id).toBe(format);
       }
     },

superset-frontend/plugins/plugin-chart-echarts/test/utils/formatters.test.ts

@@ -16,8 +16,16 @@
  * specific language governing permissions and limitations
  * under the License.
  */
-import { NumberFormats } from '@superset-ui/core';
-import { getPercentFormatter } from '../../src/utils/formatters';
+import {
+  NumberFormats,
+  SMART_DATE_ID,
+  getTimeFormatter,
+} from '@superset-ui/core';
+import {
+  getPercentFormatter,
+  getXAxisFormatter,
+  getSmartDateFormatter,
+} from '../../src/utils/formatters';
 
 describe('getPercentFormatter', () => {
   const value = 0.6;
@@ -35,3 +43,39 @@ describe('getPercentFormatter', () => {
     ).toEqual('60.00%');
   });
 });
+
+describe('getXAxisFormatter', () => {
+  it('should return smart date formatter when SMART_DATE_ID is specified', () => {
+    const formatter = getXAxisFormatter(SMART_DATE_ID);
+    expect(formatter).toBeDefined();
+    expect(formatter).toBeInstanceOf(Function);
+    // The formatter should be the same as getSmartDateFormatter()
+    const smartDateFormatter = getSmartDateFormatter();
+    expect(formatter).toEqual(smartDateFormatter);
+  });
+
+  it('should return undefined when format is not specified', () => {
+    const formatter = getXAxisFormatter();
+    expect(formatter).toBeUndefined();
+  });
+
+  it('should return undefined when format is empty string', () => {
+    const formatter = getXAxisFormatter('');
+    expect(formatter).toBeUndefined();
+  });
+
+  it('should return the appropriate time formatter for a specific format', () => {
+    const format = '%Y-%m-%d';
+    const formatter = getXAxisFormatter(format);
+    expect(formatter).toBeDefined();
+    expect(formatter).toBeInstanceOf(Function);
+    // Should return the same formatter as getTimeFormatter
+    const expectedFormatter = getTimeFormatter(format);
+    expect(formatter).toEqual(expectedFormatter);
+  });
+
+  it('should return undefined for falsy values', () => {
+    const formatter = getXAxisFormatter(null as any);
+    expect(formatter).toBeUndefined();
+  });
+});