refactor: rewrite sorting in typescript and add tests (carbon-design-system#19225)

Author: adamalston

packages/react/src/components/DataTable/tools/__tests__/sorting-test.js

@@ -1,14 +1,14 @@
 /**
- * Copyright IBM Corp. 2016, 2023
+ * Copyright IBM Corp. 2016, 2025
  *
  * This source code is licensed under the Apache-2.0 license found in the
  * LICENSE file in the root directory of this source tree.
  */
 
-import { sortRows, defaultSortRow } from '../sorting';
+import { compare, defaultSortRow, sortRows } from '../sorting';
 import { sortStates } from '../../state/sorting';
 
-describe('sortRow', () => {
+describe('sortRows', () => {
   const rowIds = ['row2', 'row1'];
   const cellsById = {
     'row1:header1': { value: 'cell11' },
@@ -53,6 +53,91 @@ describe('sortRow', () => {
       })
     ).toEqual(['row2', 'row1']);
   });
+
+  it('should sort React elements correctly', () => {
+    const reactCells1 = {
+      'row1:header1': { value: { props: { children: 'Apple' } } },
+      'row2:header1': { value: { props: { children: 'Banana' } } },
+    };
+    const reactCells2 = {
+      'row1:header1': { value: { props: { children: 1000 } } },
+      'row2:header1': { value: { props: { children: 'hmm' } } },
+    };
+
+    expect(
+      sortRows({
+        rowIds,
+        cellsById: reactCells1,
+        sortDirection: sortStates.ASC,
+        key: 'header1',
+        locale: 'en',
+        sortRow: defaultSortRow,
+      })
+    ).toEqual(['row1', 'row2']);
+    expect(
+      sortRows({
+        rowIds,
+        cellsById: reactCells2,
+        sortDirection: sortStates.ASC,
+        key: 'header1',
+        locale: 'en',
+        sortRow: defaultSortRow,
+      })
+    ).toEqual(['row2', 'row1']);
+  });
+
+  it('should sort numeric strings as numbers', () => {
+    const cells = {
+      'row1:header1': { value: '10' },
+      'row2:header1': { value: '2' },
+    };
+
+    expect(
+      sortRows({
+        rowIds,
+        cellsById: cells,
+        sortDirection: sortStates.ASC,
+        key: 'header1',
+        locale: 'en',
+      })
+    ).toEqual(['row2', 'row1']);
+  });
+
+  it('should handle a custom `sortRow` function', () => {
+    const customSortRow = (a, b) => a.length - b.length;
+
+    const customCells = {
+      'row1:header1': { value: 'short' },
+      'row2:header1': { value: 'longerstring' },
+    };
+
+    expect(
+      sortRows({
+        rowIds,
+        cellsById: customCells,
+        sortDirection: sortStates.ASC,
+        key: 'header1',
+        sortRow: customSortRow,
+      })
+    ).toEqual(['row1', 'row2']);
+  });
+
+  it('should maintain order for equal values', () => {
+    const cells = {
+      'row1:header1': { value: 'same' },
+      'row2:header1': { value: 'same' },
+    };
+
+    expect(rowIds).toEqual(['row2', 'row1']);
+    expect(
+      sortRows({
+        rowIds,
+        cellsById: cells,
+        sortDirection: sortStates.ASC,
+        key: 'header1',
+      })
+    ).toEqual(['row2', 'row1']);
+  });
 });
 
 describe('defaultSortRow', () => {
@@ -76,3 +161,65 @@ describe('defaultSortRow', () => {
     expect(defaultSortRow('1', '2', sortProps)).toBeGreaterThan(0);
   });
 });
+
+describe('compare', () => {
+  it('should treat null as empty string', () => {
+    expect(compare(null, 'abc')).toEqual(-1);
+    expect(compare(null, null)).toEqual(0);
+    expect(compare('abc', null)).toEqual(1);
+  });
+
+  it('should compare numbers correctly', () => {
+    expect(compare(10, 5)).toEqual(5);
+    expect(compare(3, 3)).toEqual(0);
+    expect(compare(1, 10)).toEqual(-9);
+  });
+
+  it('should compare mixed strings and numbers as strings', () => {
+    expect(compare('5', 10)).toEqual(-1);
+    expect(compare(20, '10')).toEqual(1);
+  });
+
+  it('should compare React elements whose `props.children` are strings', () => {
+    const a = { props: { children: 'Apple' } };
+    const b = { props: { children: 'Banana' } };
+
+    expect(compare(a, b)).toEqual(-1);
+  });
+
+  it('should fallback to string comparison when `props.children` is not a string', () => {
+    const a = { props: { children: 123 } };
+    const b = { props: { children: 'banana' } };
+
+    expect(compare(a, b)).toEqual(0);
+  });
+
+  it('should fallback to string comparison for non-matching types', () => {
+    expect(compare({}, 1)).toEqual(-1);
+    expect(compare(true, 'false')).toEqual(1);
+  });
+
+  it('should treat `undefined` as a string when comparing', () => {
+    expect(compare(undefined, 'abc')).toEqual(1);
+    expect(compare(undefined, undefined)).toEqual(0);
+    expect(compare('abc', undefined)).toEqual(-1);
+  });
+
+  it('should use locale for string comparison', () => {
+    expect(compare('ä', 'z', 'sv-SE')).toEqual(1);
+    expect(compare('z', 'ä', 'sv-SE')).toEqual(-1);
+    expect(compare('ä', 'z', 'en-US')).toEqual(-1);
+    expect(compare('z', 'ä', 'en-US')).toEqual(1);
+    expect(compare('ä', 'z', 'de-DE')).toEqual(-1);
+    expect(compare('z', 'ä', 'de-DE')).toEqual(1);
+  });
+
+  it('should compare falsy values correctly', () => {
+    expect(compare(false, true)).toEqual(-1);
+    expect(compare(true, false)).toEqual(1);
+    expect(compare(0, false)).toEqual(-1);
+    expect(compare(false, 0)).toEqual(1);
+    expect(compare(null, undefined)).toEqual(-1);
+    expect(compare(undefined, null)).toEqual(1);
+  });
+});