test(common): Restoring isEmpty method with test coverage

I got an error when running npm run test:coverage.

The @nestjs/graphql package depends on the isEmpty function from @nestjs/common.

After renaming isEmpty to isEmptyArray, the @nestjs/graphql package can no longer find the isEmpty function, leading to the error.

To fix this issue, I restored the isEmpty function for the @nestjs/graphql package.

Author: BrahimAbdelli

packages/common/test/utils/shared.utils.spec.ts

@@ -2,6 +2,7 @@ import { expect } from 'chai';
 import {
   addLeadingSlash,
   isConstructor,
+  isEmpty,
   isEmptyArray,
   isFunction,
   isNil,
@@ -48,9 +49,7 @@ describe('Shared utils', () => {
     it('should return true when obj is object', () => {
       expect(isObject({})).to.be.true;
     });
-    it('should return true for arrays', () => {
-      expect(isObject([1, 2, 3])).to.be.true; // Arrays are objects
-    });
+
     it('should return false when object is not object', () => {
       expect(isObject(3)).to.be.false;
       expect(isObject(null)).to.be.false;
@@ -199,6 +198,24 @@ describe('Shared utils', () => {
     });
   });
 
+  describe('isEmpty', () => {
+    it('should return true when array is empty or not exists', () => {
+      expect(isEmpty([])).to.be.true;
+    });
+
+    it('should return false when array is not empty', () => {
+      expect(isEmpty([1, 2])).to.be.false;
+    });
+    it('should return false for non-array values', () => {
+      expect(isEmpty({})).to.be.false;
+      expect(isEmpty('')).to.be.false;
+      expect(isEmpty(0)).to.be.false;
+      expect(isEmpty(false)).to.be.false;
+      expect(isEmpty(Symbol())).to.be.false;
+      expect(isEmpty(() => {})).to.be.false;
+    });
+  });
+
   describe('isEmptyArray', () => {
     it('should return true when array is empty or not exists', () => {
       expect(isEmptyArray([])).to.be.true;

packages/common/utils/shared.utils.ts

@@ -54,6 +54,16 @@ export const isConstructor = (val: unknown): boolean => val === 'constructor';
 export const isNil = (val: unknown): val is null | undefined =>
   isUndefined(val) || val === null;
 
+export const isEmpty = (value: unknown): boolean => {
+  if (isNil(value)) {
+    return true;
+  }
+  if (Array.isArray(value)) {
+    return value.length === 0;
+  }
+  return false;
+};
+
 export const isEmptyArray = (array: unknown): boolean => {
   if (isNil(array)) {
     return true;