fix: chaning Date to objects in flat.set error

src/utils/flat/set.spec.ts

@@ -33,14 +33,22 @@ describe('module:flat.set', () => {
   context('passing basic types', () => {
     const newPropertyName = 'newProperty'
 
-    it('does not change the record when regular file is set', function () {
+    it('does not change the type when regular file is set', function () {
       const file = new File([], 'amazing.me')
 
       newParams = set(params, newPropertyName, file)
 
       expect(newParams[newPropertyName]).to.equal(file)
     })
 
+    it('does not change the type when Date is set', () => {
+      const date = new Date()
+
+      newParams = set(params, newPropertyName, date)
+
+      expect(newParams[newPropertyName]).to.equal(date)
+    })
+
     it('sets null', () => {
       expect(set(params, newPropertyName, null)).to.have.property(newPropertyName, null)
     })

src/utils/flat/set.ts

@@ -30,7 +30,7 @@ const set = (params: FlattenParams = {}, propertyPath: string, value?: any): Fla
     .reduce((memo, key) => ({ ...memo, [key]: params[key] }), {} as FlattenParams)
 
   if (typeof value !== 'undefined') {
-    if (isObject(value)) {
+    if (isObject(value) && !(value instanceof Date)) {
       const flattened = flatten(value) as any
 
       if (Object.keys(flattened).length) {