test(metrics): make sure metadata is kept

src/metrics/decorators/common.spec.ts

@@ -0,0 +1,37 @@
+import 'reflect-metadata';
+import { SetMetadata } from '@nestjs/common';
+import { OtelInstanceCounter, OtelMethodCounter } from './common';
+
+const TestDecoratorThatSetsMetadata = () => SetMetadata('some-metadata', true);
+
+@OtelInstanceCounter()
+@TestDecoratorThatSetsMetadata()
+class TestClass {
+  @TestDecoratorThatSetsMetadata()
+  @OtelMethodCounter()
+  method() {}
+}
+
+describe('OtelInstanceCounter', () => {
+  let instance: TestClass;
+
+  beforeEach(() => {
+    instance = new TestClass();
+  });
+
+  it('should maintain reflect metadata', async () => {
+    expect(Reflect.getMetadata('some-metadata', instance.constructor)).toEqual(true);
+  });
+});
+
+describe('OtelMethodCounter', () => {
+  let instance: TestClass;
+
+  beforeEach(() => {
+    instance = new TestClass();
+  });
+
+  it('should maintain reflect metadata', async () => {
+    expect(Reflect.getMetadata('some-metadata', instance.method)).toEqual(true);
+  });
+});