feat(@nestjs/graphql): add support for skipNullProperties in PartialType

packages/graphql/lib/type-helpers/partial-type.helper.ts

@@ -2,6 +2,7 @@ import { Type } from '@nestjs/common';
 import { isFunction } from '@nestjs/common/utils/shared.utils';
 import {
   applyIsOptionalDecorator,
+  applyValidateIfDefinedDecorator,
   inheritPropertyInitializers,
   inheritTransformationMetadata,
   inheritValidationMetadata,
@@ -17,6 +18,7 @@ import { applyFieldDecorators } from './type-helpers.utils';
 interface PartialTypeOptions {
   decorator?: ClassDecoratorFactory;
   omitDefaultValues?: boolean;
+  skipNullProperties?: boolean;
 }
 
 function isPartialTypeOptions(
@@ -25,7 +27,8 @@ function isPartialTypeOptions(
   return (
     optionsOrDecorator &&
     ('decorator' in optionsOrDecorator ||
-      'omitDefaultValues' in optionsOrDecorator)
+      'omitDefaultValues' in optionsOrDecorator ||
+      'skipNullProperties' in optionsOrDecorator)
   );
 }
 
@@ -42,13 +45,20 @@ export function PartialType<T>(
 
   let decorator: ClassDecoratorFactory | undefined;
   let omitDefaultValues = false;
+  let skipNullProperties = true;
   if (isPartialTypeOptions(optionsOrDecorator)) {
     decorator = optionsOrDecorator.decorator;
     omitDefaultValues = optionsOrDecorator.omitDefaultValues;
+    skipNullProperties = optionsOrDecorator.skipNullProperties ?? true;
   } else {
     decorator = optionsOrDecorator;
   }
 
+  const applyPartialDecoratorFn =
+    skipNullProperties === false
+      ? applyValidateIfDefinedDecorator
+      : applyIsOptionalDecorator;
+
   if (decorator) {
     decorator({ isAbstract: true })(PartialObjectType);
   } else {
@@ -70,7 +80,7 @@ export function PartialType<T>(
         nullable: true,
         defaultValue: omitDefaultValues ? undefined : item.options.defaultValue,
       })(PartialObjectType.prototype, item.name);
-      applyIsOptionalDecorator(PartialObjectType, item.name);
+      applyPartialDecoratorFn(PartialObjectType, item.name);
       applyFieldDecorators(PartialObjectType, item);
     });
   }
@@ -90,7 +100,7 @@ export function PartialType<T>(
       PartialObjectType[METADATA_FACTORY_NAME](),
     );
     pluginFields.forEach((key) =>
-      applyIsOptionalDecorator(PartialObjectType, key),
+      applyPartialDecoratorFn(PartialObjectType, key),
     );
   }
 

packages/graphql/tests/plugin/type-helpers/partial-type.helper.spec.ts

@@ -10,6 +10,10 @@ import { getValidationMetadataByTarget } from './type-helpers.test-utils';
 
 @ObjectType()
 class CreateUserDto extends BaseType {
+  @IsString()
+  @Field()
+  firstName: string;
+
   @Field({ nullable: true })
   login: string;
 
@@ -31,7 +35,7 @@ describe('PartialType', () => {
     const prototype = Object.getPrototypeOf(UpdateUserDto);
     const { fields } = getFieldsAndDecoratorForType(prototype);
 
-    expect(fields.length).toEqual(6);
+    expect(fields.length).toEqual(7);
     expect(fields).toEqual(
       expect.arrayContaining([
         expect.objectContaining({
@@ -54,6 +58,10 @@ describe('PartialType', () => {
           name: 'password',
           options: { nullable: true },
         }),
+        expect.objectContaining({
+          name: 'firstName',
+          options: { nullable: true },
+        }),
         expect.objectContaining({
           name: 'meta',
           options: { nullable: true },
@@ -79,6 +87,7 @@ describe('PartialType', () => {
         ),
       );
       expect(Array.from(validationKeys)).toEqual([
+        'firstName',
         'password',
         'id',
         'createdAt',
@@ -87,6 +96,12 @@ describe('PartialType', () => {
         'meta',
       ]);
     });
+    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);
+    });
     describe('when object does not fulfil validation rules', () => {
       it('"validate" should return validation errors', async () => {
         const updateDto = new UpdateUserDto();
@@ -125,4 +140,39 @@ describe('PartialType', () => {
       expect(fields[0].options.defaultValue).toEqual(undefined);
     });
   });
+
+  describe('skipNullProperties', () => {
+    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, {
+        skipNullProperties: undefined,
+      }) {}
+      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',
+      });
+    });
+  });
 });