fix: incorrect inherit _transformmetadatas nestjs#1224

KuanWenChen · Nov 14, 2023 · 8bbc2c3 · 8bbc2c3
1 parent d98e446
commit 8bbc2c3
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Showing 2 changed files with 59 additions and 2 deletions.
diff --git a/lib/type-helpers.utils.ts b/lib/type-helpers.utils.ts
@@ -151,11 +151,18 @@ function inheritTransformerMetadata(
 
       if (metadataMap.has(targetClass)) {
         const existingRules = metadataMap.get(targetClass)!.entries();
+        // _transformMetadatas is array, should merge not overwrite
         const mergeMap = new Map<string, any[]>();
         [existingRules, targetMetadataEntries].forEach((entries) => {
           for (const [valueKey, value] of entries) {
             if (mergeMap.has(valueKey)) {
-              mergeMap.get(valueKey)!.push(...value);
+              if (Array.isArray(mergeMap.get(valueKey))) {
+                mergeMap
+                  .get(valueKey)!
+                  .push(...(Array.isArray(value) ? value : [value])); // merge, if value is not array, transfer to Array
+              } else {
+                mergeMap.set(valueKey, value); // overwrite
+              }
             } else {
               mergeMap.set(valueKey, value);
             }

diff --git a/tests/omit-type.helper.spec.ts b/tests/omit-type.helper.spec.ts
@@ -1,4 +1,10 @@
-import { instanceToInstance, Transform } from 'class-transformer';
+import {
+  Expose,
+  instanceToInstance,
+  plainToInstance,
+  Transform,
+  Type,
+} from 'class-transformer';
 import { MinLength, validate } from 'class-validator';
 import { OmitType } from '../lib';
 import { getValidationMetadataByTarget } from './type-helpers.test-utils';
@@ -58,6 +64,50 @@ describe('OmitType', () => {
       const transformedDto = instanceToInstance(updateDto);
       expect(transformedDto.password).toEqual(password + '_transformed');
     });
+
+    it('should inherit expose and type transformer metadata', () => {
+      class Parent {
+        @Expose()
+        a!: string | number;
+
+        @Expose()
+        @Type(() => Number)
+        b!: string | number;
+      }
+      class Children extends Parent {
+        @Expose()
+        b!: string | number;
+        c!: string; // not expose
+
+        @Type(() => Number)
+        d!: string | number;
+      }
+      class ChildrenOmit extends OmitType(Children, ['a']) {
+        @Expose()
+        @Type(() => String)
+        b!: string;
+
+        @Expose()
+        @Type(() => String)
+        d!: string;
+      }
+
+      const childrenOmitInstance = plainToInstance(
+        ChildrenOmit,
+        { a: 'a', b: 'b', c: 'c', d: 'd' },
+        { excludeExtraneousValues: true },
+      );
+
+      const expectKeySet = new Set(['b', 'd']);
+      const concreteKeyList = Object.keys(childrenOmitInstance);
+      for (let i = 0; i < concreteKeyList.length; i++) {
+        expect(expectKeySet.has(concreteKeyList[i])).toEqual(true);
+      }
+      expect(concreteKeyList.length).toEqual(expectKeySet.size);
+      expect(typeof childrenOmitInstance.b).toEqual('string');
+      expect(typeof childrenOmitInstance.d).toEqual('string');
+      expect(childrenOmitInstance.b).toEqual('b');
+    });
   });
 
   describe('Property initializers', () => {