feat(nestjs): Add function-level span decorator to nestjs

dev-packages/e2e-tests/test-applications/nestjs/src/app.controller.ts

@@ -69,6 +69,11 @@ export class AppController1 {
   async testOutgoingHttpExternalDisallowed() {
     return this.appService.testOutgoingHttpExternalDisallowed();
   }
+
+  @Get('test-span-decorator')
+  async testSpanDecorator() {
+    return this.appService.testSpanDecorator();
+  }
 }
 
 @Controller()

dev-packages/e2e-tests/test-applications/nestjs/src/app.service.ts

@@ -1,5 +1,6 @@
 import { HttpException, HttpStatus, Injectable } from '@nestjs/common';
 import * as Sentry from '@sentry/nestjs';
+import { SentryTraced } from '@sentry/nestjs';
 import { makeHttpRequest } from './utils';
 
 @Injectable()
@@ -75,6 +76,15 @@ export class AppService1 {
   async testOutgoingHttpExternalDisallowed() {
     return makeHttpRequest('http://localhost:3040/external-disallowed');
   }
+
+  @SentryTraced('wait function')
+  async wait() {
+    return new Promise(resolve => setTimeout(resolve, 500));
+  }
+
+  async testSpanDecorator() {
+    await this.wait();
+  }
 }
 
 @Injectable()

dev-packages/e2e-tests/test-applications/nestjs/tests/span-decorator.test.ts

@@ -0,0 +1,31 @@
+import { expect, test } from '@playwright/test';
+import { waitForTransaction } from '@sentry-internal/test-utils';
+
+test('Transaction includes span for decorated function', async ({ baseURL }) => {
+  const transactionEventPromise = waitForTransaction('nestjs', transactionEvent => {
+    return (
+      transactionEvent?.contexts?.trace?.op === 'http.server' &&
+      transactionEvent?.transaction === 'GET /test-span-decorator'
+    );
+  });
+
+  await fetch(`${baseURL}/test-span-decorator`);
+
+  const transactionEvent = await transactionEventPromise;
+
+  expect(transactionEvent.spans).toEqual(
+    expect.arrayContaining([
+      expect.objectContaining({
+        span_id: expect.any(String),
+        trace_id: expect.any(String),
+        data: expect.any(Object),
+        description: 'wait',
+        parent_span_id: expect.any(String),
+        start_timestamp: expect.any(Number),
+        status: 'ok',
+        op: 'wait function',
+        origin: 'manual',
+      }),
+    ]),
+  );
+});

packages/nestjs/README.md

@@ -38,6 +38,24 @@ Sentry.init({
 
 Note that it is necessary to initialize Sentry **before you import any package that may be instrumented by us**.
 
+## Span Decorator
+
+Use the @SentryTraced() decorator to gain additional performance insights for any function within your NestJS
+application.
+
+```js
+import { Injectable } from '@nestjs/common';
+import { SentryTraced } from '@sentry/nestjs';
+
+@Injectable()
+export class ExampleService {
+  @SentryTraced('example function')
+  async performTask() {
+    // Your business logic here
+  }
+}
+```
+
 ## Links
 
 - [Official SDK Docs](https://docs.sentry.io/platforms/javascript/guides/nestjs/)

packages/nestjs/src/index.ts

@@ -1,3 +1,5 @@
 export * from '@sentry/node';
 
 export { init } from './sdk';
+
+export * from './span-decorator';

packages/nestjs/src/span-decorator.ts

@@ -0,0 +1,29 @@
+import { captureException, startSpan } from '@sentry/node';
+
+/**
+ * A decorator usable to wrap arbitrary functions with spans.
+ */
+export function SentryTraced(op: string = 'function') {
+  return function (target: unknown, propertyKey: string, descriptor: PropertyDescriptor) {
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    const originalMethod = descriptor.value as (...args: any[]) => Promise<any>;
+
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    descriptor.value = async function (...args: any[]) {
+      await startSpan(
+        {
+          op: op,
+          name: propertyKey,
+        },
+        async () => {
+          try {
+            return await originalMethod.apply(this, args);
+          } catch (e) {
+            captureException(e);
+          }
+        },
+      );
+    };
+    return descriptor;
+  };
+}