test(common): added test to generic decorators scenarios

Author: galesky

packages/common/test/decorators/create-param-decorator.spec.ts

@@ -102,4 +102,76 @@ describe('createParamDecorator', () => {
       });
     });
   });
+
+  describe('returned generic typed decorator', () => {
+    const factoryFn = (data, req) => true;
+    interface User {
+      name: string;
+    }
+
+    const stringOnlyDecorator = createParamDecorator<string>(factoryFn);
+    const stringOrNumberDecorator = createParamDecorator<string | number>(
+      factoryFn,
+    );
+    const customTypeDecorator = createParamDecorator<User>(factoryFn);
+
+    describe('when string is passed to stringOnlyDecorator', () => {
+      const data = 'test';
+      class Test {
+        public test(
+          @stringOnlyDecorator(data)
+          param,
+        ) {}
+      }
+      it('should enhance param with "data" as string', () => {
+        const metadata = Reflect.getMetadata(ROUTE_ARGS_METADATA, Test, 'test');
+        const key = Object.keys(metadata)[0];
+        expect(metadata[key]).to.be.eql({
+          data: 'test',
+          factory: factoryFn,
+          index: 0,
+          pipes: [],
+        });
+      });
+    });
+
+    describe('when number is passed to stringOrNumberDecorator', () => {
+      const data = 10;
+      class Test {
+        public test(
+          @stringOrNumberDecorator(data)
+          param,
+        ) {}
+      }
+      it('should enhance param with "data" as number', () => {
+        const metadata = Reflect.getMetadata(ROUTE_ARGS_METADATA, Test, 'test');
+        const key = Object.keys(metadata)[0];
+        expect(metadata[key]).to.be.eql({
+          data: 10,
+          factory: factoryFn,
+          index: 0,
+          pipes: [],
+        });
+      });
+    });
+    describe('when a custom Type is passed to customTypeDecorator', () => {
+      const data = { name: 'john' };
+      class Test {
+        public test(
+          @customTypeDecorator(data)
+          param,
+        ) {}
+      }
+      it('should enhance param with "data" as custom Type', () => {
+        const metadata = Reflect.getMetadata(ROUTE_ARGS_METADATA, Test, 'test');
+        const key = Object.keys(metadata)[0];
+        expect(metadata[key]).to.be.eql({
+          data: { name: 'john' },
+          factory: factoryFn,
+          index: 0,
+          pipes: [],
+        });
+      });
+    });
+  });
 });