Merge pull request #2863 from NovikovEvgeny/partial-type-helper-add-skip-null-option

feat: add skip null properties option to partial type

Author: kamilmysliwiec

Diff for: lib/type-helpers/partial-type.helper.ts

@@ -1,6 +1,7 @@
 import { Type } from '@nestjs/common';
 import {
   applyIsOptionalDecorator,
+  applyValidateIfDefinedDecorator,
   inheritPropertyInitializers,
   inheritTransformationMetadata,
   inheritValidationMetadata
@@ -15,7 +16,25 @@ import { clonePluginMetadataFactory } from './mapped-types.utils';
 
 const modelPropertiesAccessor = new ModelPropertiesAccessor();
 
-export function PartialType<T>(classRef: Type<T>): Type<Partial<T>> {
+export function PartialType<T>(
+  classRef: Type<T>,
+  /**
+   *  Configuration options.
+   */
+  options: {
+    /**
+     * If true, validations will be ignored on a property if it is either null or undefined. If
+     * false, validations will be ignored only if the property is undefined.
+     * @default true
+     */
+    skipNullProperties?: boolean;
+  } = {}
+): Type<Partial<T>> {
+  const applyPartialDecoratorFn =
+    options.skipNullProperties === false
+      ? applyValidateIfDefinedDecorator
+      : applyIsOptionalDecorator;
+
   const fields = modelPropertiesAccessor.getModelProperties(classRef.prototype);
 
   abstract class PartialTypeClass {
@@ -30,7 +49,7 @@ export function PartialType<T>(classRef: Type<T>): Type<Partial<T>> {
   if (keysWithValidationConstraints) {
     keysWithValidationConstraints
       .filter((key) => !fields.includes(key))
-      .forEach((key) => applyIsOptionalDecorator(PartialTypeClass, key));
+      .forEach((key) => applyPartialDecoratorFn(PartialTypeClass, key));
   }
 
   inheritTransformationMetadata(classRef, PartialTypeClass);
@@ -48,7 +67,7 @@ export function PartialType<T>(classRef: Type<T>): Type<Partial<T>> {
         PartialTypeClass[METADATA_FACTORY_NAME]()
       );
       pluginFields.forEach((key) =>
-        applyIsOptionalDecorator(PartialTypeClass, key)
+        applyPartialDecoratorFn(PartialTypeClass, key)
       );
     }
 
@@ -65,7 +84,7 @@ export function PartialType<T>(classRef: Type<T>): Type<Partial<T>> {
         required: false
       });
       decoratorFactory(PartialTypeClass.prototype, key);
-      applyIsOptionalDecorator(PartialTypeClass, key);
+      applyPartialDecoratorFn(PartialTypeClass, key);
     });
   }
   applyFields(fields);

Diff for: test/type-helpers/partial-type.helper.spec.ts

@@ -21,9 +21,44 @@ describe('PartialType', () => {
   describe('Validation metadata', () => {
     it('should apply @IsOptional to properties reflected by the plugin', async () => {
       const updateDto = new UpdateUserDto();
+      updateDto.firstName = null;
       const validationErrors = await validate(updateDto);
       expect(validationErrors).toHaveLength(0);
     });
+
+    it('should apply @IsOptional to properties reflected by the plugin if option `skipNullProperties` is true', async () => {
+      class UpdateUserWithNullableDto extends PartialType(CreateUserDto, {
+        skipNullProperties: true
+      }) {}
+      const updateDto = new UpdateUserWithNullableDto();
+      updateDto.firstName = null;
+      const validationErrors = await validate(updateDto);
+      expect(validationErrors).toHaveLength(0);
+    });
+
+    it('should apply @IsOptional to properties reflected by the plugin if option `skipNullProperties` is undefined', async () => {
+      class UpdateUserWithoutNullableDto extends PartialType(
+        CreateUserDto,
+        {}
+      ) {}
+      const updateDto = new UpdateUserWithoutNullableDto();
+      updateDto.firstName = null;
+      const validationErrors = await validate(updateDto);
+      expect(validationErrors).toHaveLength(0);
+    });
+
+    it('should apply @ValidateIf to properties reflected by the plugin if option `skipNullProperties` is false', async () => {
+      class UpdateUserWithoutNullableDto extends PartialType(CreateUserDto, {
+        skipNullProperties: false
+      }) {}
+      const updateDto = new UpdateUserWithoutNullableDto();
+      updateDto.firstName = null;
+      const validationErrors = await validate(updateDto);
+      expect(validationErrors).toHaveLength(1);
+      expect(validationErrors[0].constraints).toEqual({
+        isString: 'firstName must be a string'
+      });
+    });
   });
   describe('OpenAPI metadata', () => {
     it('should return partial class', async () => {