test(core): added tests to optional file

src/v2/core/optional.ts

@@ -1,6 +1,16 @@
 /**
  * Return the defaultValue whether the value is undefined, otherwise, return the value.
  *
+ * @example```typescript
+ * const value1 = getDefaultIfUndefined(undefined, true);
+ * const value2 = getDefaultIfUndefined(false, true);
+ *
+ * console.log(value1);
+ * // true
+ * console.log(value2);
+ * // false
+ * ```
+ *
  * @param value The value to be checked
  * @param defaultValue The default value when value is undefined
  */

test/core/optional.spec.ts

@@ -0,0 +1,32 @@
+import { getDefaultIfUndefined } from '../../src/v2/core';
+
+describe('getDefaultIfUndefined', () => {
+  it('should return the value when value is not undefined', () => {
+    const options: [testValue: any, defaultValue: any, expectedValue: any][] = [
+      ['batata', 'potato', 'batata'],
+      [true, false, true],
+      [false, true, false],
+    ];
+
+    for (const [testValue, defaultValue, expectedValue] of options) {
+      expect(getDefaultIfUndefined(testValue, defaultValue)).toBe(
+        expectedValue,
+      );
+    }
+  });
+
+  it('should return the default value when value is undefined', () => {
+    const options: [testValue: any, defaultValue: any, expectedValue: any][] = [
+      [undefined, true, true],
+      [undefined, 'text', 'text'],
+      [void 0, true, true],
+      [void 0, 'text', 'text'],
+    ];
+
+    for (const [testValue, defaultValue, expectedValue] of options) {
+      expect(getDefaultIfUndefined(testValue, defaultValue)).toBe(
+        expectedValue,
+      );
+    }
+  });
+});