Add jsdoc and unit tests for util functions

utils/array.test.ts

@@ -0,0 +1,130 @@
+import { describe, expect, it } from 'bun:test';
+import { multArray, multBy, sumArray, sumBy } from './array.ts';
+
+describe('array utils', () => {
+  it('sumArray number array', () => {
+    const array = [1, 2, 3];
+    const sum = sumArray(array);
+    expect(sum).toBeNumber();
+    expect(sum).toBeFinite();
+    expect(sum).toBe(1 + 2 + 3);
+
+    expect(sumArray([])).toBeNumber();
+    expect(sumArray([])).toBeFinite();
+    expect(sumArray([])).toBe(0);
+  });
+  it('sumArray read-only number array', () => {
+    const array = [1, 2, 3] as const;
+    const sum = sumArray(array);
+    expect(sum).toBeNumber();
+    expect(sum).toBeFinite();
+    expect(sum).toBe(1 + 2 + 3);
+
+    expect(sumArray([])).toBeNumber();
+    expect(sumArray([])).toBeFinite();
+    expect(sumArray([])).toBe(0);
+  });
+  it('sumBy number array', () => {
+    const array = [1, 2, 3];
+    const sum = sumBy(array, (e) => e);
+    expect(sum).toBeNumber();
+    expect(sum).toBeFinite();
+    expect(sum).toBe(1 + 2 + 3);
+  });
+  it('sumBy read-only number array', () => {
+    const array = [1, 2, 3] as const;
+    const sum = sumBy(array, (e) => e);
+    expect(sum).toBeNumber();
+    expect(sum).toBeFinite();
+    expect(sum).toBe(1 + 2 + 3);
+  });
+  it('sumBy mixed array', () => {
+    const array = [1, '2', 3.1, ''];
+
+    const sum = sumBy(array, (e) => e);
+    expect(sum).toBeNumber();
+    expect(sum).toBeFinite();
+    expect(sum).toBe(1 + 2 + 3.1);
+  });
+  it('sumBy object array', () => {
+    const array: (
+      | { value: number | string }
+      | { differentValue: number | string }
+    )[] = [{ value: 3 }, { value: '2' }, { differentValue: '-2.44' }];
+
+    const sum = sumBy(array, (e) =>
+      'differentValue' in e ? e.differentValue : e.value
+    );
+    expect(sum).toBeNumber();
+    expect(sum).toBeFinite();
+    expect(sum).toBe(3 + 2 - 2.44);
+  });
+  it('sumBy empty array', () => {
+    expect(sumBy([], (e) => e)).toBeNumber();
+    expect(sumBy([], (e) => e)).toBeFinite();
+    expect(sumBy([], (e) => e)).toBe(0);
+  });
+
+  it('multArray number array', () => {
+    const array = [1, 2, 3];
+    const sum = multArray(array);
+    expect(sum).toBeNumber();
+    expect(sum).toBeFinite();
+    expect(sum).toBe(2 * 3);
+
+    expect(multArray([])).toBeNumber();
+    expect(multArray([])).toBeFinite();
+    expect(multArray([])).toBe(0);
+  });
+  it('multArray read-only number array', () => {
+    const array = [1, 2, 3] as const;
+    const sum = multArray(array);
+    expect(sum).toBeNumber();
+    expect(sum).toBeFinite();
+    expect(sum).toBe(2 * 3);
+
+    expect(multArray([])).toBeNumber();
+    expect(multArray([])).toBeFinite();
+    expect(multArray([])).toBe(0);
+  });
+  it('multBy number array', () => {
+    const array = [1, 2, 3];
+    const sum = sumBy(array, (e) => e);
+    expect(sum).toBeNumber();
+    expect(sum).toBeFinite();
+    expect(sum).toBe(1 + 2 + 3);
+  });
+  it('multBy read-only number array', () => {
+    const array = [1, 2, 3] as const;
+    const sum = multBy(array, (e) => e);
+    expect(sum).toBeNumber();
+    expect(sum).toBeFinite();
+    expect(sum).toBe(1 + 2 + 3);
+  });
+  it('multBy mixed array', () => {
+    const array = [1, '2', 3.1, ''];
+
+    const sum = multBy(array, (e) => e);
+    expect(sum).toBeNumber();
+    expect(sum).toBeFinite();
+    expect(sum).toBe(0);
+  });
+  it('multBy object array', () => {
+    const array: (
+      | { value: number | string }
+      | { differentValue: number | string }
+    )[] = [{ value: 3 }, { value: '2' }, { differentValue: '-2.44' }];
+
+    const sum = multBy(array, (e) =>
+      'differentValue' in e ? e.differentValue : e.value
+    );
+    expect(sum).toBeNumber();
+    expect(sum).toBeFinite();
+    expect(sum).toBe(3 * 2 * -2.44);
+  });
+  it('multBy empty array', () => {
+    expect(multBy([], (e) => e)).toBeNumber();
+    expect(multBy([], (e) => e)).toBeFinite();
+    expect(multBy([], (e) => e)).toBe(0);
+  });
+});