feat(node): Warn if ESM mode is detected

dev-packages/node-integration-tests/suites/esm/warn-esm/server.js

@@ -0,0 +1,21 @@
+const { loggingTransport } = require('@sentry-internal/node-integration-tests');
+const Sentry = require('@sentry/node');
+
+Sentry.init({
+  dsn: 'https://public@dsn.ingest.sentry.io/1337',
+  release: '1.0',
+  transport: loggingTransport,
+});
+
+const { startExpressServerAndSendPortToRunner } = require('@sentry-internal/node-integration-tests');
+const express = require('express');
+
+const app = express();
+
+app.get('/test/success', (req, res) => {
+  res.send({ response: 'response 3' });
+});
+
+Sentry.setupExpressErrorHandler(app);
+
+startExpressServerAndSendPortToRunner(app);

dev-packages/node-integration-tests/suites/esm/warn-esm/server.mjs

@@ -0,0 +1,21 @@
+import { loggingTransport } from '@sentry-internal/node-integration-tests';
+import * as Sentry from '@sentry/node';
+
+Sentry.init({
+  dsn: 'https://public@dsn.ingest.sentry.io/1337',
+  release: '1.0',
+  transport: loggingTransport,
+});
+
+import { startExpressServerAndSendPortToRunner } from '@sentry-internal/node-integration-tests';
+import express from 'express';
+
+const app = express();
+
+app.get('/test/success', (req, res) => {
+  res.send({ response: 'response 3' });
+});
+
+Sentry.setupExpressErrorHandler(app);
+
+startExpressServerAndSendPortToRunner(app);

dev-packages/node-integration-tests/suites/esm/warn-esm/test.ts

@@ -0,0 +1,24 @@
+import { cleanupChildProcesses, createRunner } from '../../../utils/runner';
+
+afterAll(() => {
+  cleanupChildProcesses();
+});
+
+const esmWarning =
+  '[Sentry] You are using the Sentry SDK with an ESM build. This version of the SDK is not compatible with ESM. Please either build your application with CommonJS, or use v7 of the SDK.';
+
+test('warns if using ESM', async () => {
+  const runner = createRunner(__dirname, 'server.mjs').ignore('session', 'sessions', 'event').start();
+
+  await runner.makeRequest('get', '/test/success');
+
+  expect(runner.getLogs()).toContain(esmWarning);
+});
+
+test('does not warn if using CJS', async () => {
+  const runner = createRunner(__dirname, 'server.js').ignore('session', 'sessions', 'event').start();
+
+  await runner.makeRequest('get', '/test/success');
+
+  expect(runner.getLogs()).not.toContain(esmWarning);
+});

dev-packages/node-integration-tests/utils/runner.ts

@@ -159,6 +159,7 @@ export function createRunner(...paths: string[]) {
   let dockerOptions: DockerOptions | undefined;
   let ensureNoErrorOutput = false;
   let expectError = false;
+  const logs: string[] = [];
 
   if (testPath.endsWith('.ts')) {
     flags.push('-r', 'ts-node/register');
@@ -335,12 +336,14 @@ export function createRunner(...paths: string[]) {
             child?.kill();
           });
 
-          if (ensureNoErrorOutput) {
-            child.stderr?.on('data', (data: Buffer) => {
-              const output = data.toString();
+          child.stderr?.on('data', (data: Buffer) => {
+            const output = data.toString();
+            logs.push(output.trim());
+
+            if (ensureNoErrorOutput) {
               complete(new Error(`Expected no error output but got: '${output}'`));
-            });
-          }
+            }
+          });
 
           child.on('close', () => {
             hasExited = true;
@@ -389,6 +392,8 @@ export function createRunner(...paths: string[]) {
             let splitIndex = -1;
             while ((splitIndex = buffer.indexOf(0xa)) >= 0) {
               const line = buffer.subarray(0, splitIndex).toString();
+              logs.push(line.trim());
+
               buffer = Buffer.from(buffer.subarray(splitIndex + 1));
               // eslint-disable-next-line no-console
               if (process.env.DEBUG) console.log('line', line);
@@ -402,6 +407,9 @@ export function createRunner(...paths: string[]) {
         childHasExited: function (): boolean {
           return hasExited;
         },
+        getLogs(): string[] {
+          return logs;
+        },
         makeRequest: async function <T>(
           method: 'get' | 'post',
           path: string,

packages/node/src/sdk/init.ts

@@ -39,8 +39,12 @@ import { defaultStackParser, getSentryRelease } from './api';
 import { NodeClient } from './client';
 import { initOpenTelemetry } from './initOtel';
 
-function getCjsOnlyIntegrations(isCjs = typeof require !== 'undefined'): Integration[] {
-  return isCjs ? [modulesIntegration()] : [];
+function isCjs(): boolean {
+  return typeof require !== 'undefined';
+}
+
+function getCjsOnlyIntegrations(): Integration[] {
+  return isCjs() ? [modulesIntegration()] : [];
 }
 
 /** Get the default integrations for the Node Experimental SDK. */
@@ -85,6 +89,16 @@ export function init(options: NodeOptions | undefined = {}): void {
     }
   }
 
+  if (!isCjs()) {
+    // We want to make sure users see this warning
+    consoleSandbox(() => {
+      // eslint-disable-next-line no-console
+      console.warn(
+        '[Sentry] You are using the Sentry SDK with an ESM build. This version of the SDK is not compatible with ESM. Please either build your application with CommonJS, or use v7 of the SDK.',
+      );
+    });
+  }
+
   setOpenTelemetryContextAsyncContextStrategy();
 
   const scope = getCurrentScope();