feat(): inherit property initializers

nestjs · Aug 20, 2020 · 565e256 · 565e256
1 parent 8828473
commit 565e256
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Showing 9 changed files with 95 additions and 25 deletions.
diff --git a/lib/intersection-type.helper.ts b/lib/intersection-type.helper.ts
@@ -1,5 +1,6 @@
 import { Type } from '@nestjs/common';
 import {
+  inheritPropertyInitializers,
   inheritTransformationMetadata,
   inheritValidationMetadata,
 } from './type-helpers.utils';
@@ -8,7 +9,12 @@ export function IntersectionType<A, B>(
   classARef: Type<A>,
   classBRef: Type<B>,
 ): Type<A & B> {
-  abstract class IntersectionClassType {}
+  abstract class IntersectionClassType {
+    constructor() {
+      inheritPropertyInitializers(this, classARef);
+      inheritPropertyInitializers(this, classBRef);
+    }
+  }
 
   inheritValidationMetadata(classARef, IntersectionClassType);
   inheritValidationMetadata(classBRef, IntersectionClassType);

diff --git a/lib/omit-type.helper.ts b/lib/omit-type.helper.ts
@@ -1,5 +1,6 @@
 import { Type } from '@nestjs/common';
 import {
+  inheritPropertyInitializers,
   inheritTransformationMetadata,
   inheritValidationMetadata,
 } from './type-helpers.utils';
@@ -8,10 +9,15 @@ export function OmitType<T, K extends keyof T>(
   classRef: Type<T>,
   keys: readonly K[],
 ): Type<Omit<T, typeof keys[number]>> {
-  abstract class OmitClassType {}
-
   const isInheritedPredicate = (propertyKey: string) =>
     !keys.includes(propertyKey as K);
+
+  abstract class OmitClassType {
+    constructor() {
+      inheritPropertyInitializers(this, classRef, isInheritedPredicate);
+    }
+  }
+
   inheritValidationMetadata(classRef, OmitClassType, isInheritedPredicate);
   inheritTransformationMetadata(classRef, OmitClassType, isInheritedPredicate);
 

diff --git a/lib/partial-type.helper.ts b/lib/partial-type.helper.ts
@@ -1,18 +1,23 @@
 import { Type } from '@nestjs/common';
 import {
   applyIsOptionalDecorator,
+  inheritPropertyInitializers,
   inheritTransformationMetadata,
   inheritValidationMetadata,
 } from './type-helpers.utils';
 
 export function PartialType<T>(classRef: Type<T>): Type<Partial<T>> {
-  abstract class PartialClassType {}
+  abstract class PartialClassType {
+    constructor() {
+      inheritPropertyInitializers(this, classRef);
+    }
+  }
 
   const propertyKeys = inheritValidationMetadata(classRef, PartialClassType);
   inheritTransformationMetadata(classRef, PartialClassType);
 
   if (propertyKeys) {
-    propertyKeys.forEach(key => {
+    propertyKeys.forEach((key) => {
       applyIsOptionalDecorator(PartialClassType, key);
     });
   }

diff --git a/lib/pick-type.helper.ts b/lib/pick-type.helper.ts
@@ -1,5 +1,6 @@
 import { Type } from '@nestjs/common';
 import {
+  inheritPropertyInitializers,
   inheritTransformationMetadata,
   inheritValidationMetadata,
 } from './type-helpers.utils';
@@ -8,10 +9,14 @@ export function PickType<T, K extends keyof T>(
   classRef: Type<T>,
   keys: readonly K[],
 ): Type<Pick<T, typeof keys[number]>> {
-  abstract class PickClassType {}
-
   const isInheritedPredicate = (propertyKey: string) =>
     keys.includes(propertyKey as K);
+
+  abstract class PickClassType {
+    constructor() {
+      inheritPropertyInitializers(this, classRef, isInheritedPredicate);
+    }
+  }
   inheritValidationMetadata(classRef, PickClassType, isInheritedPredicate);
   inheritTransformationMetadata(classRef, PickClassType, isInheritedPredicate);
 

diff --git a/lib/type-helpers.utils.ts b/lib/type-helpers.utils.ts
@@ -155,3 +155,26 @@ function isClassTransformerAvailable() {
     return false;
   }
 }
+
+export function inheritPropertyInitializers(
+  target: Record<string, any>,
+  sourceClass: Type<any>,
+  // eslint-disable-next-line @typescript-eslint/no-unused-vars
+  isPropertyInherited = (key: string) => true,
+) {
+  try {
+    const tempInstance = new sourceClass();
+    const propertyNames = Object.getOwnPropertyNames(tempInstance);
+
+    propertyNames
+      .filter(
+        (propertyName) =>
+          typeof tempInstance[propertyName] !== 'undefined' &&
+          typeof target[propertyName] === 'undefined',
+      )
+      .filter((propertyName) => isPropertyInherited(propertyName))
+      .forEach((propertyName) => {
+        target[propertyName] = tempInstance[propertyName];
+      });
+  } catch {}
+}
diff --git a/tests/intersection-type.helper.spec.ts b/tests/intersection-type.helper.spec.ts
@@ -6,18 +6,18 @@ import { getValidationMetadataByTarget } from './type-helpers.test-utils';
 describe('IntersectionType', () => {
   class ClassA {
     @MinLength(10)
-    login!: string;
+    login = 'defaultLoginWithMin10Chars';
 
-    @Transform(str => str + '_transformed')
+    @Transform((str) => str + '_transformed')
     @MinLength(10)
     password!: string;
   }
 
   class ClassB {
     @IsString()
-    firstName!: string;
+    firstName = 'defaultFirst';
 
-    @Transform(str => str + '_transformed')
+    @Transform((str) => str + '_transformed')
     @MinLength(5)
     lastName!: string;
   }
@@ -27,7 +27,7 @@ describe('IntersectionType', () => {
   describe('Validation metadata', () => {
     it('should inherit metadata for all properties from class A and class B', () => {
       const validationKeys = getValidationMetadataByTarget(UpdateUserDto).map(
-        item => item.propertyName,
+        (item) => item.propertyName,
       );
       expect(validationKeys).toEqual([
         'login',
@@ -43,17 +43,11 @@ describe('IntersectionType', () => {
 
         const validationErrors = await validate(updateDto);
 
-        expect(validationErrors.length).toEqual(4);
+        expect(validationErrors.length).toEqual(2);
         expect(validationErrors[0].constraints).toEqual({
-          minLength: 'login must be longer than or equal to 10 characters',
-        });
-        expect(validationErrors[1].constraints).toEqual({
           minLength: 'password must be longer than or equal to 10 characters',
         });
-        expect(validationErrors[2].constraints).toEqual({
-          isString: 'firstName must be a string',
-        });
-        expect(validationErrors[3].constraints).toEqual({
+        expect(validationErrors[1].constraints).toEqual({
           minLength: 'lastName must be longer than or equal to 5 characters',
         });
       });
@@ -86,4 +80,12 @@ describe('IntersectionType', () => {
       expect(transformedDto.password).toEqual(password + '_transformed');
     });
   });
+
+  describe('Property initializers', () => {
+    it('should inherit property initializers', () => {
+      const updateUserDto = new UpdateUserDto();
+      expect(updateUserDto.login).toEqual('defaultLoginWithMin10Chars');
+      expect(updateUserDto.firstName).toEqual('defaultFirst');
+    });
+  });
 });
diff --git a/tests/omit-type.helper.spec.ts b/tests/omit-type.helper.spec.ts
@@ -10,7 +10,7 @@ describe('OmitType', () => {
 
     @Transform((str) => str + '_transformed')
     @MinLength(10)
-    password!: string;
+    password = 'defaultPassword';
   }
 
   class UpdateUserDto extends OmitType(CreateUserDto, ['login']) {}
@@ -56,4 +56,12 @@ describe('OmitType', () => {
       expect(transformedDto.password).toEqual(password + '_transformed');
     });
   });
+
+  describe('Property initializers', () => {
+    it('should inherit property initializers', () => {
+      const updateUserDto = new UpdateUserDto();
+      expect((updateUserDto as any)['login']).toBeUndefined();
+      expect(updateUserDto.password).toEqual('defaultPassword');
+    });
+  });
 });
diff --git a/tests/partial-type.helper.spec.ts b/tests/partial-type.helper.spec.ts
@@ -12,7 +12,7 @@ describe('PartialType', () => {
   }
 
   class CreateUserDto extends BaseUserDto {
-    login!: string;
+    login: string = 'defaultLogin';
 
     @Expose()
     @Transform((str) => str + '_transformed')
@@ -74,4 +74,11 @@ describe('PartialType', () => {
       );
     });
   });
+
+  describe('Property initializers', () => {
+    it('should inherit property initializers', () => {
+      const updateUserDto = new UpdateUserDto();
+      expect(updateUserDto.login).toEqual('defaultLogin');
+    });
+  });
 });
diff --git a/tests/pick-type.helper.spec.ts b/tests/pick-type.helper.spec.ts
@@ -5,9 +5,9 @@ import { getValidationMetadataByTarget } from './type-helpers.test-utils';
 
 describe('PickType', () => {
   class CreateUserDto {
-    @Transform(str => str + '_transformed')
+    @Transform((str) => str + '_transformed')
     @MinLength(10)
-    login!: string;
+    login = 'defaultLogin';
 
     @MinLength(10)
     password!: string;
@@ -18,7 +18,7 @@ describe('PickType', () => {
   describe('Validation metadata', () => {
     it('should inherit metadata with "password" property excluded', () => {
       const validationKeys = getValidationMetadataByTarget(UpdateUserDto).map(
-        item => item.propertyName,
+        (item) => item.propertyName,
       );
       expect(validationKeys).toEqual(['login']);
     });
@@ -56,4 +56,12 @@ describe('PickType', () => {
       expect(transformedDto.login).toEqual(login + '_transformed');
     });
   });
+
+  describe('Property initializers', () => {
+    it('should inherit property initializers', () => {
+      const updateUserDto = new UpdateUserDto();
+      expect((updateUserDto as any)['password']).toBeUndefined();
+      expect(updateUserDto.login).toEqual('defaultLogin');
+    });
+  });
 });