feat: add an option to IsObject to exclude functions from object checks

README.md

@@ -867,7 +867,7 @@ isBoolean(value);
 | `@IsISO8601(options?: IsISO8601Options)`               | Checks if the string is a valid ISO 8601 date format. Use the option strict = true for additional checks for a valid date.                                                                            |
 | `@IsJSON()`                                            | Checks if the string is valid JSON.                                                                                                                                                                   |
 | `@IsJWT()`                                             | Checks if the string is valid JWT.                                                                                                                                                                    |
-| `@IsObject()`                                          | Checks if the object is valid Object (null, functions, arrays will return false).                                                                                                                     |
+| `@IsObject(options: IsObjectOptions)`                  | Checks if the object is valid Object (null, arrays will return false).                                                                                                                                |
 | `@IsNotEmptyObject()`                                  | Checks if the object is not empty.                                                                                                                                                                    |
 | `@IsLowercase()`                                       | Checks if the string is lowercase.                                                                                                                                                                    |
 | `@IsLatLong()`                                         | Checks if the string is a valid latitude-longitude coordinate in the format lat, long.                                                                                                                |

src/decorator/typechecker/IsObject.ts

@@ -3,24 +3,36 @@ import { buildMessage, ValidateBy } from '../common/ValidateBy';
 
 export const IS_OBJECT = 'isObject';
 
+/**
+ * Options to be passed to IsObject decorator.
+ */
+export interface IsObjectOptions {
+  excludeFunctions?: boolean;
+}
+
 /**
  * Checks if the value is valid Object.
  * Returns false if the value is not an object.
  */
-export function isObject<T = object>(value: unknown): value is T {
-  return value != null && (typeof value === 'object' || typeof value === 'function') && !Array.isArray(value);
+export function isObject<T = object>(value: unknown, options: IsObjectOptions = {}): value is T {
+  return (
+    value != null &&
+    (typeof value === 'object' || (typeof value === 'function' && !options.excludeFunctions)) &&
+    !Array.isArray(value)
+  );
 }
 
 /**
  * Checks if the value is valid Object.
  * Returns false if the value is not an object.
  */
-export function IsObject(validationOptions?: ValidationOptions): PropertyDecorator {
+export function IsObject(options: IsObjectOptions = {}, validationOptions?: ValidationOptions): PropertyDecorator {
   return ValidateBy(
     {
       name: IS_OBJECT,
+      constraints: [options],
       validator: {
-        validate: (value, args): boolean => isObject(value),
+        validate: (value, args): boolean => isObject(value, args?.constraints[0]),
         defaultMessage: buildMessage(eachPrefix => eachPrefix + '$property must be an object', validationOptions),
       },
     },

test/functional/validation-functions-and-decorators.spec.ts

@@ -3171,6 +3171,11 @@ describe('IsObject', () => {
     someProperty: object;
   }
 
+  class ExcludeFunctionsTestClass {
+    @IsObject({ excludeFunctions: true })
+    someProperty: object;
+  }
+
   it('should not fail if validator.validate said that its valid', () => {
     return checkValidValues(new MyClass(), validValues);
   });
@@ -3192,6 +3197,10 @@ describe('IsObject', () => {
     const message = 'someProperty must be an object';
     return checkReturnedError(new MyClass(), invalidValues, validationType, message);
   });
+
+  it('should fail if excludeFunctions is true and the value is a function', () => {
+    return checkInvalidValues(new ExcludeFunctionsTestClass(), [function () {}]);
+  });
 });
 
 describe('IsNotEmptyObject', () => {