[Lens] Improve column type detection in table for alignment (#120007)

* 🐛 Fix last value alignment behaviour

* ✅ Add unit test

x-pack/plugins/lens/public/datatable_visualization/components/table_basic.test.tsx

@@ -508,6 +508,52 @@ describe('DatatableComponent', () => {
     });
   });
 
+  test('it detect last_value filtered metric type', () => {
+    const { data, args } = sampleArgs();
+
+    const table = data.tables.l1;
+    const column = table.columns[1];
+
+    column.meta = {
+      ...column.meta,
+      field: undefined,
+      type: 'number',
+      sourceParams: { ...column.meta.sourceParams, type: 'filtered_metric' },
+    };
+    table.rows[0].b = 'Hello';
+
+    const wrapper = shallow(
+      <DatatableComponent
+        data={data}
+        args={{
+          ...args,
+          columns: [
+            { columnId: 'a', alignment: 'center', type: 'lens_datatable_column' },
+            { columnId: 'b', type: 'lens_datatable_column' },
+            { columnId: 'c', type: 'lens_datatable_column' },
+          ],
+          sortingColumnId: 'b',
+          sortingDirection: 'desc',
+        }}
+        formatFactory={() => ({ convert: (x) => x } as IFieldFormat)}
+        dispatchEvent={onDispatchEvent}
+        getType={jest.fn()}
+        renderMode="view"
+        paletteService={chartPluginMock.createPaletteRegistry()}
+        uiSettings={{ get: jest.fn() } as unknown as IUiSettingsClient}
+      />
+    );
+
+    expect(wrapper.find(DataContext.Provider).prop('value').alignments).toEqual({
+      // set via args
+      a: 'center',
+      // default for string
+      b: 'left',
+      // default for number
+      c: 'right',
+    });
+  });
+
   test('it should refresh the table header when the datatable data changes', () => {
     const { data, args } = sampleArgs();
 

x-pack/plugins/lens/public/datatable_visualization/components/table_basic.tsx

@@ -212,7 +212,14 @@ export const DatatableComponent = (props: DatatableRenderProps) => {
   const isNumericMap: Record<string, boolean> = useMemo(() => {
     const numericMap: Record<string, boolean> = {};
     for (const column of firstLocalTable.columns) {
-      numericMap[column.id] = column.meta.type === 'number';
+      // filtered metrics result as "number" type, but have no field
+      numericMap[column.id] =
+        (column.meta.type === 'number' && column.meta.field != null) ||
+        // as fallback check the first available value type
+        // mind here: date can be seen as numbers, to carefully check that is a filtered metric
+        (column.meta.field == null &&
+          typeof firstLocalTable.rows.find((row) => row[column.id] != null)?.[column.id] ===
+            'number');
     }
     return numericMap;
   }, [firstLocalTable]);