[EuiInMemoryTable] Fix onTableChange returning the sort field's name instead of field key

CHANGELOG.md

@@ -1,6 +1,8 @@
 ## [`main`](https://github.com/elastic/eui/tree/main)
 
-No public interface changes since `46.2.0`.
+**Bug fixes**
+
+- Fixed `EuiInMemoryTable`'s `onTableChange` callback not returning the correct `sort.field` value on pagination ([#5588](https://github.com/elastic/eui/pull/5588))
 
 ## [`46.2.0`](https://github.com/elastic/eui/tree/v46.2.0)
 

src/components/basic_table/in_memory_table.test.tsx

@@ -1015,28 +1015,29 @@ describe('EuiInMemoryTable', () => {
       };
 
       const component = mount(<EuiInMemoryTable {...props} />);
-
       expect(props.onTableChange).toHaveBeenCalledTimes(0);
+
+      // Pagination change
       component
         .find('EuiButtonEmpty[data-test-subj="pagination-button-1"]')
         .simulate('click');
       expect(props.onTableChange).toHaveBeenCalledTimes(1);
-      expect(props.onTableChange).toHaveBeenCalledWith({
+      expect(props.onTableChange).toHaveBeenLastCalledWith({
         sort: {},
         page: {
           index: 1,
           size: 2,
         },
       });
 
-      (props.onTableChange as jest.Mock).mockClear();
+      // Sorting change
       component
         .find(
           '[data-test-subj*="tableHeaderCell_name_0"] [data-test-subj="tableHeaderSortButton"]'
         )
         .simulate('click');
-      expect(props.onTableChange).toHaveBeenCalledTimes(1);
-      expect(props.onTableChange).toHaveBeenCalledWith({
+      expect(props.onTableChange).toHaveBeenCalledTimes(2);
+      expect(props.onTableChange).toHaveBeenLastCalledWith({
         sort: {
           direction: SortDirection.ASC,
           field: 'name',
@@ -1046,6 +1047,22 @@ describe('EuiInMemoryTable', () => {
           size: 2,
         },
       });
+
+      // Sorted pagination change
+      component
+        .find('EuiButtonEmpty[data-test-subj="pagination-button-1"]')
+        .simulate('click');
+      expect(props.onTableChange).toHaveBeenCalledTimes(3);
+      expect(props.onTableChange).toHaveBeenLastCalledWith({
+        sort: {
+          direction: SortDirection.ASC,
+          field: 'name',
+        },
+        page: {
+          index: 1,
+          size: 2,
+        },
+      });
     });
   });
 

src/components/basic_table/in_memory_table.tsx

@@ -188,7 +188,7 @@ const getInitialPagination = (pagination: Pagination | undefined) => {
 function findColumnByProp<T>(
   columns: Array<EuiBasicTableColumn<T>>,
   prop: 'field' | 'name',
-  value: string
+  value: string | ReactNode
 ) {
   for (let i = 0; i < columns.length; i++) {
     const column = columns[i];
@@ -202,6 +202,19 @@ function findColumnByProp<T>(
   }
 }
 
+function findColumnByFieldOrName<T>(
+  columns: Array<EuiBasicTableColumn<T>>,
+  value: string | ReactNode
+) {
+  // The passed value can be a column's `field` or its `name`
+  // for backwards compatibility `field` must be checked first
+  let column = findColumnByProp(columns, 'field', value);
+  if (column == null) {
+    column = findColumnByProp(columns, 'name', value);
+  }
+  return column;
+}
+
 function getInitialSorting<T>(
   columns: Array<EuiBasicTableColumn<T>>,
   sorting: Sorting | undefined
@@ -218,12 +231,7 @@ function getInitialSorting<T>(
     direction: sortDirection,
   } = (sorting as SortingOptions).sort;
 
-  // sortable could be a column's `field` or its `name`
-  // for backwards compatibility `field` must be checked first
-  let sortColumn = findColumnByProp(columns, 'field', sortable);
-  if (sortColumn == null) {
-    sortColumn = findColumnByProp(columns, 'name', sortable);
-  }
+  const sortColumn = findColumnByFieldOrName(columns, sortable);
 
   if (sortColumn == null) {
     return {
@@ -401,16 +409,17 @@ export class EuiInMemoryTable<T> extends Component<
     // from sortName; sortName gets stored internally while reportedSortName is sent to the callback
     let reportedSortName = sortName;
 
-    // EuiBasicTable returns the column's `field` if it exists instead of `name`,
-    // map back to `name` if this is the case
-    for (let i = 0; i < this.props.columns.length; i++) {
-      const column = this.props.columns[i];
-      if (
-        'field' in column &&
-        (column as EuiTableFieldDataColumnType<T>).field === sortName
-      ) {
-        sortName = column.name as keyof T;
-        break;
+    // EuiBasicTable returns the column's `field` instead of `name` on sort
+    // and the column's `name` instead of `field` on pagination
+    if (sortName) {
+      const sortColumn = findColumnByFieldOrName(this.props.columns, sortName);
+      if (sortColumn) {
+        // Ensure sortName uses `name`
+        sortName = sortColumn.name as keyof T;
+
+        // Ensure reportedSortName uses `field` if it exists
+        const sortField = (sortColumn as EuiTableFieldDataColumnType<T>).field;
+        if (sortField) reportedSortName = sortField as keyof T;
       }
     }