test(common): improve test coverage for shared utils

packages/common/pipes/file/parse-file.pipe.ts

@@ -2,7 +2,7 @@ import { Injectable, Optional } from '../../decorators/core';
 import { HttpStatus } from '../../enums';
 import { PipeTransform } from '../../interfaces/features/pipe-transform.interface';
 import { HttpErrorByCode } from '../../utils/http-error-by-code.util';
-import { isEmpty, isObject, isUndefined } from '../../utils/shared.utils';
+import { isEmptyArray, isObject, isUndefined } from '../../utils/shared.utils';
 import { FileValidator } from './file-validator.interface';
 import { ParseFileOptions } from './parse-file-options.interface';
 
@@ -60,9 +60,8 @@ export class ParseFilePipe implements PipeTransform<any> {
   }
 
   private thereAreNoFilesIn(value: any): boolean {
-    const isEmptyArray = Array.isArray(value) && isEmpty(value);
-    const isEmptyObject = isObject(value) && isEmpty(Object.keys(value));
-    return isUndefined(value) || isEmptyArray || isEmptyObject;
+    const isEmptyObject = isObject(value) && isEmptyArray(Object.keys(value));
+    return isUndefined(value) || isEmptyArray(value) || isEmptyObject;
   }
 
   protected async validate(file: any): Promise<any> {

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

@@ -3,6 +3,7 @@ import {
   addLeadingSlash,
   isConstructor,
   isEmpty,
+  isEmptyArray,
   isFunction,
   isNil,
   isNumber,
@@ -27,7 +28,13 @@ describe('Shared utils', () => {
     it('should return false when object is not undefined', () => {
       expect(isUndefined({})).to.be.false;
     });
+    it('should return false for falsy values like false, 0, or empty string', () => {
+      expect(isUndefined(false)).to.be.false;
+      expect(isUndefined(0)).to.be.false;
+      expect(isUndefined('')).to.be.false;
+    });
   });
+
   describe('isFunction', () => {
     it('should return true when obj is function', () => {
       expect(isFunction(() => ({}))).to.be.true;
@@ -37,16 +44,19 @@ describe('Shared utils', () => {
       expect(isFunction(undefined)).to.be.false;
     });
   });
+
   describe('isObject', () => {
     it('should return true when obj is object', () => {
       expect(isObject({})).to.be.true;
     });
+
     it('should return false when object is not object', () => {
       expect(isObject(3)).to.be.false;
       expect(isObject(null)).to.be.false;
       expect(isObject(undefined)).to.be.false;
     });
   });
+
   describe('isPlainObject', () => {
     it('should return true when obj is plain object', () => {
       expect(isPlainObject({})).to.be.true;
@@ -66,7 +76,12 @@ describe('Shared utils', () => {
       expect(isPlainObject(new Date())).to.be.false;
       expect(isPlainObject(new Foo(1))).to.be.false;
     });
+    it('should return false for objects with custom prototypes', () => {
+      function CustomObject() {}
+      expect(isPlainObject(new CustomObject())).to.be.false;
+    });
   });
+
   describe('isString', () => {
     it('should return true when val is a string', () => {
       expect(isString('true')).to.be.true;
@@ -78,6 +93,7 @@ describe('Shared utils', () => {
       expect(isString(undefined)).to.be.false;
     });
   });
+
   describe('isSymbol', () => {
     it('should return true when val is a Symbol', () => {
       expect(isSymbol(Symbol())).to.be.true;
@@ -88,7 +104,11 @@ describe('Shared utils', () => {
       expect(isSymbol(null)).to.be.false;
       expect(isSymbol(undefined)).to.be.false;
     });
+    it('should return false for invalid Symbol objects', () => {
+      expect(isSymbol(Object(Symbol()))).to.be.false;
+    });
   });
+
   describe('isNumber', () => {
     it('should return true when val is a number or NaN', () => {
       expect(isNumber(1)).to.be.true;
@@ -98,22 +118,32 @@ describe('Shared utils', () => {
       expect(isNumber(0b1)).to.be.true; // binary notation
       expect(isNumber(0x1)).to.be.true; // hexadecimal notation
       expect(isNumber(NaN)).to.be.true;
+      expect(isNumber(Infinity)).to.be.true;
+      expect(isNumber(-Infinity)).to.be.true;
     });
     it('should return false when val is not a number', () => {
       // expect(isNumber(1n)).to.be.false; // big int (available on ES2020)
       expect(isNumber('1')).to.be.false; // string
       expect(isNumber(undefined)).to.be.false; // nullish
       expect(isNumber(null)).to.be.false; // nullish
+      expect(isNumber(new Number(123))).to.be.false; // number
     });
   });
+
   describe('isConstructor', () => {
     it('should return true when string is equal to constructor', () => {
       expect(isConstructor('constructor')).to.be.true;
     });
     it('should return false when string is not equal to constructor', () => {
       expect(isConstructor('nope')).to.be.false;
     });
+    it('should return false for non-string values', () => {
+      expect(isConstructor(null)).to.be.false;
+      expect(isConstructor(undefined)).to.be.false;
+      expect(isConstructor(123)).to.be.false;
+    });
   });
+
   describe('addLeadingSlash', () => {
     it('should return the validated path ("add / if not exists")', () => {
       expect(addLeadingSlash('nope')).to.be.eql('/nope');
@@ -128,7 +158,13 @@ describe('Shared utils', () => {
       expect(addLeadingSlash(null!)).to.be.eql('');
       expect(addLeadingSlash(undefined)).to.be.eql('');
     });
+    it('should handle paths with special characters', () => {
+      expect(addLeadingSlash('path-with-special-chars!@#$%^&*()')).to.eql(
+        '/path-with-special-chars!@#$%^&*()',
+      );
+    });
   });
+
   describe('normalizePath', () => {
     it('should remove all trailing slashes at the end of the path', () => {
       expect(normalizePath('path/')).to.be.eql('/path');
@@ -146,6 +182,7 @@ describe('Shared utils', () => {
       expect(normalizePath(undefined)).to.be.eql('/');
     });
   });
+
   describe('isNil', () => {
     it('should return true when obj is undefined or null', () => {
       expect(isNil(undefined)).to.be.true;
@@ -154,17 +191,64 @@ describe('Shared utils', () => {
     it('should return false when object is not undefined and null', () => {
       expect(isNil('3')).to.be.false;
     });
+    it('should return false for falsy values like false, 0, or empty string', () => {
+      expect(isNil(false)).to.be.false;
+      expect(isNil(0)).to.be.false;
+      expect(isNil('')).to.be.false;
+    });
   });
+
   describe('isEmpty', () => {
     it('should return true when array is empty or not exists', () => {
       expect(isEmpty([])).to.be.true;
-      expect(isEmpty(null)).to.be.true;
-      expect(isEmpty(undefined)).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;
+      expect(isEmptyArray(null)).to.be.true;
+      expect(isEmptyArray(undefined)).to.be.true;
+    });
+
+    it('should return false when array is not empty', () => {
+      expect(isEmptyArray([1, 2])).to.be.false;
+      expect(isEmptyArray(['a', 'b', 'c'])).to.be.false;
+      expect(isEmptyArray([{}])).to.be.false;
+    });
+
+    it('should return false for non-array values', () => {
+      expect(isEmptyArray({})).to.be.false;
+      expect(isEmptyArray('')).to.be.false;
+      expect(isEmptyArray(0)).to.be.false;
+      expect(isEmptyArray(false)).to.be.false;
+      expect(isEmptyArray(Symbol())).to.be.false;
+      expect(isEmptyArray(() => {})).to.be.false;
+    });
+
+    it('should return false for array-like objects', () => {
+      expect(isEmptyArray({ length: 0 })).to.be.false;
+      expect(isEmptyArray({ length: 1 })).to.be.false;
+    });
+
+    it('should return false for sparse arrays', () => {
+      const sparseArray = new Array(3);
+      expect(isEmptyArray(sparseArray)).to.be.false;
+    });
+  });
+
   describe('stripEndSlash', () => {
     it('should strip end slash if present', () => {
       expect(stripEndSlash('/cats/')).to.equal('/cats');

packages/common/utils/shared.utils.ts

@@ -1,10 +1,10 @@
-export const isUndefined = (obj: any): obj is undefined =>
+export const isUndefined = (obj: unknown): obj is undefined =>
   typeof obj === 'undefined';
 
-export const isObject = (fn: any): fn is object =>
+export const isObject = (fn: unknown): fn is object =>
   !isNil(fn) && typeof fn === 'object';
 
-export const isPlainObject = (fn: any): fn is object => {
+export const isPlainObject = (fn: unknown): fn is object => {
   if (!isObject(fn)) {
     return false;
   }
@@ -37,15 +37,39 @@ export const normalizePath = (path?: string): string =>
       : '/' + path.replace(/\/+$/, '')
     : '/';
 
-export const stripEndSlash = (path: string) =>
-  path[path.length - 1] === '/' ? path.slice(0, path.length - 1) : path;
+export const stripEndSlash = (path: string): string =>
+  path.endsWith('/') ? path.slice(0, -1) : path;
 
-export const isFunction = (val: any): val is Function =>
+export const isFunction = (val: unknown): val is Function =>
   typeof val === 'function';
-export const isString = (val: any): val is string => typeof val === 'string';
-export const isNumber = (val: any): val is number => typeof val === 'number';
-export const isConstructor = (val: any): boolean => val === 'constructor';
-export const isNil = (val: any): val is null | undefined =>
+
+export const isString = (val: unknown): val is string =>
+  typeof val === 'string';
+
+export const isNumber = (val: unknown): val is number =>
+  typeof val === 'number';
+
+export const isConstructor = (val: unknown): boolean => val === 'constructor';
+
+export const isNil = (val: unknown): val is null | undefined =>
   isUndefined(val) || val === null;
-export const isEmpty = (array: any): boolean => !(array && array.length > 0);
-export const isSymbol = (val: any): val is symbol => typeof val === 'symbol';
+
+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;
+  }
+  return Array.isArray(array) && array.length === 0;
+};
+
+export const isSymbol = (val: unknown): val is symbol =>
+  typeof val === 'symbol';

packages/core/exceptions/base-exception-filter-context.ts

@@ -1,7 +1,7 @@
 import { FILTER_CATCH_EXCEPTIONS } from '@nestjs/common/constants';
 import { Type } from '@nestjs/common/interfaces';
 import { ExceptionFilter } from '@nestjs/common/interfaces/exceptions/exception-filter.interface';
-import { isEmpty, isFunction } from '@nestjs/common/utils/shared.utils';
+import { isEmptyArray, isFunction } from '@nestjs/common/utils/shared.utils';
 import { iterate } from 'iterare';
 import { ContextCreator } from '../helpers/context-creator';
 import { STATIC_CONTEXT } from '../injector/constants';
@@ -20,7 +20,7 @@ export class BaseExceptionFilterContext extends ContextCreator {
     contextId = STATIC_CONTEXT,
     inquirerId?: string,
   ): R {
-    if (isEmpty(metadata)) {
+    if (isEmptyArray(metadata)) {
       return [] as any[] as R;
     }
     return iterate(metadata)

packages/core/exceptions/exceptions-handler.ts

@@ -2,7 +2,7 @@ import { HttpException } from '@nestjs/common';
 import { ExceptionFilterMetadata } from '@nestjs/common/interfaces/exceptions/exception-filter-metadata.interface';
 import { ArgumentsHost } from '@nestjs/common/interfaces/features/arguments-host.interface';
 import { selectExceptionFilterMetadata } from '@nestjs/common/utils/select-exception-filter-metadata.util';
-import { isEmpty } from '@nestjs/common/utils/shared.utils';
+import { isEmptyArray } from '@nestjs/common/utils/shared.utils';
 import { InvalidExceptionFilterException } from '../errors/exceptions/invalid-exception-filter.exception';
 import { BaseExceptionFilter } from './base-exception-filter';
 
@@ -27,7 +27,7 @@ export class ExceptionsHandler extends BaseExceptionFilter {
     exception: T,
     ctx: ArgumentsHost,
   ): boolean {
-    if (isEmpty(this.filters)) {
+    if (isEmptyArray(this.filters)) {
       return false;
     }
 

packages/core/exceptions/external-exception-filter-context.ts

@@ -1,7 +1,7 @@
 import { EXCEPTION_FILTERS_METADATA } from '@nestjs/common/constants';
 import { Controller } from '@nestjs/common/interfaces';
 import { ExceptionFilterMetadata } from '@nestjs/common/interfaces/exceptions';
-import { isEmpty } from '@nestjs/common/utils/shared.utils';
+import { isEmptyArray } from '@nestjs/common/utils/shared.utils';
 import { iterate } from 'iterare';
 import { ApplicationConfig } from '../application-config';
 import { STATIC_CONTEXT } from '../injector/constants';
@@ -36,7 +36,7 @@ export class ExternalExceptionFilterContext extends BaseExceptionFilterContext {
       contextId,
       inquirerId,
     );
-    if (isEmpty(filters)) {
+    if (isEmptyArray(filters)) {
       return exceptionHandler;
     }
     exceptionHandler.setCustomFilters(filters.reverse());

packages/core/exceptions/external-exceptions-handler.ts

@@ -1,7 +1,7 @@
 import { ExceptionFilterMetadata } from '@nestjs/common/interfaces/exceptions';
 import { ArgumentsHost } from '@nestjs/common/interfaces/features/arguments-host.interface';
 import { selectExceptionFilterMetadata } from '@nestjs/common/utils/select-exception-filter-metadata.util';
-import { isEmpty } from '@nestjs/common/utils/shared.utils';
+import { isEmptyArray } from '@nestjs/common/utils/shared.utils';
 import { InvalidExceptionFilterException } from '../errors/exceptions/invalid-exception-filter.exception';
 import { ExternalExceptionFilter } from './external-exception-filter';
 
@@ -27,7 +27,7 @@ export class ExternalExceptionsHandler extends ExternalExceptionFilter {
     exception: T,
     host: ArgumentsHost,
   ): Promise<any> | null {
-    if (isEmpty(this.filters)) {
+    if (isEmptyArray(this.filters)) {
       return null;
     }
 

packages/core/guards/guards-consumer.ts

@@ -1,6 +1,6 @@
 import { CanActivate } from '@nestjs/common';
 import { ContextType, Controller } from '@nestjs/common/interfaces';
-import { isEmpty } from '@nestjs/common/utils/shared.utils';
+import { isEmptyArray } from '@nestjs/common/utils/shared.utils';
 import { lastValueFrom, Observable } from 'rxjs';
 import { ExecutionContextHost } from '../helpers/execution-context-host';
 
@@ -12,7 +12,7 @@ export class GuardsConsumer {
     callback: (...args: unknown[]) => unknown,
     type?: TContext,
   ): Promise<boolean> {
-    if (!guards || isEmpty(guards)) {
+    if (!guards || isEmptyArray(guards)) {
       return true;
     }
     const context = this.createContext(args, instance, callback);

packages/core/guards/guards-context-creator.ts

@@ -1,7 +1,7 @@
 import { CanActivate } from '@nestjs/common';
 import { GUARDS_METADATA } from '@nestjs/common/constants';
 import { Controller, Type } from '@nestjs/common/interfaces';
-import { isEmpty, isFunction } from '@nestjs/common/utils/shared.utils';
+import { isEmptyArray, isFunction } from '@nestjs/common/utils/shared.utils';
 import { iterate } from 'iterare';
 import { ApplicationConfig } from '../application-config';
 import { ContextCreator } from '../helpers/context-creator';
@@ -41,7 +41,7 @@ export class GuardsContextCreator extends ContextCreator {
     contextId = STATIC_CONTEXT,
     inquirerId?: string,
   ): R {
-    if (isEmpty(metadata)) {
+    if (isEmptyArray(metadata)) {
       return [] as unknown[] as R;
     }
     return iterate(metadata)