feat(sveltekit): Only inject fetch proxy script for SvelteKit < 2.16.0

dev-packages/e2e-tests/test-applications/sveltekit-2-twp/package.json → dev-packages/e2e-tests/test-applications/sveltekit-2.5.0-twp/package.json

@@ -1,5 +1,5 @@
 {
- "name": "sveltekit-2-svelte-5",
+ "name": "sveltekit-2.5.0-twp",
  "version": "0.0.1",
  "private": true,
  "scripts": {
@@ -22,7 +22,7 @@
  "@sentry-internal/test-utils": "link:../../../test-utils",
  "@sentry/core": "latest || *",
  "@sveltejs/adapter-auto": "^3.0.0",
- "@sveltejs/kit": "^2.0.0",
+ "@sveltejs/kit": "2.5.0",
  "@sveltejs/vite-plugin-svelte": "^3.0.0",
  "svelte": "^5.0.0-next.115",
  "svelte-check": "^3.6.0",

dev-packages/e2e-tests/test-applications/sveltekit-2-twp/start-event-proxy.mjs → dev-packages/e2e-tests/test-applications/sveltekit-2.5.0-twp/start-event-proxy.mjs

@@ -2,5 +2,5 @@ import { startEventProxyServer } from '@sentry-internal/test-utils';
 
 startEventProxyServer({
  port: 3031,
- proxyServerName: 'sveltekit-2-twp',
+ proxyServerName: 'sveltekit-2.5.0-twp',
 });

dev-packages/e2e-tests/test-applications/sveltekit-2-twp/tests/errors.test.ts → dev-packages/e2e-tests/test-applications/sveltekit-2.5.0-twp/tests/errors.test.ts

@@ -2,11 +2,11 @@ import { expect, test } from '@playwright/test';
 import { waitForError } from '@sentry-internal/test-utils';
 
 test('errors on frontend and backend are connected by the same trace', async ({ page }) => {
- const clientErrorPromise = waitForError('sveltekit-2-twp', evt => {
+ const clientErrorPromise = waitForError('sveltekit-2.5.0-twp', evt => {
  return evt.exception?.values?.[0].value === 'Client Error';
  });
 
- const serverErrorPromise = waitForError('sveltekit-2-twp', evt => {
+ const serverErrorPromise = waitForError('sveltekit-2.5.0-twp', evt => {
  return evt.exception?.values?.[0].value === 'No search query provided';
  });
 

dev-packages/e2e-tests/test-applications/sveltekit-2.5.0-twp/tests/sdk.test.ts

@@ -0,0 +1,16 @@
+import { expect, test } from '@playwright/test';
+
+test.describe('SDK-internal behavior', () => {
+ test('Injects fetch proxy script for SvelteKit<2.16.0', async ({ page }) => {
+ await page.goto('/');
+
+ const sentryCarrier = await page.evaluate('typeof window.__SENTRY__');
+ const proxyHandle = await page.evaluate('typeof window._sentryFetchProxy');
+
+ // sanity check
+ expect(sentryCarrier).toBe('object');
+
+ // fetch proxy script ran
+ expect(proxyHandle).toBe('function');
+ });
+});

dev-packages/e2e-tests/test-applications/sveltekit-2/package.json

@@ -23,7 +23,7 @@
  "@sentry/core": "latest || *",
  "@sveltejs/adapter-auto": "^3.0.0",
  "@sveltejs/adapter-node": "^2.0.0",
- "@sveltejs/kit": "^2.5.0",
+ "@sveltejs/kit": "^2.16.0",
  "@sveltejs/vite-plugin-svelte": "^3.0.0",
  "svelte": "^4.2.8",
  "svelte-check": "^3.6.0",

dev-packages/e2e-tests/test-applications/sveltekit-2/tests/sdk.test.ts

@@ -0,0 +1,16 @@
+import { expect, test } from '@playwright/test';
+import { waitForInitialPageload } from './utils';
+
+test.describe('SDK-internal behavior', () => {
+ test("Doesn't inject fetch proxy script for SvelteKit>=2.16.0", async ({ page }) => {
+ await waitForInitialPageload(page, { route: '/' });
+ const sentryCarrier = await page.evaluate('typeof window.__SENTRY__');
+ const proxyHandle = await page.evaluate('typeof window._sentryFetchProxy');
+
+ // sanity check
+ expect(sentryCarrier).toBe('object');
+
+ // fetch proxy script didn't run
+ expect(proxyHandle).toBe('undefined');
+ });
+});

packages/sveltekit/package.json

@@ -9,9 +9,7 @@
  "engines": {
  "node": ">=18"
  },
- "files": [
- "/build"
- ],
+ "files": ["/build"],
  "main": "build/cjs/index.server.js",
  "module": "build/esm/index.server.js",
  "browser": "build/esm/index.client.js",

packages/sveltekit/src/server/handle.ts

@@ -93,10 +93,10 @@ export function addSentryCodeToPage(options: { injectFetchProxyScript: boolean }
  * ```
  */
 export function sentryHandle(handlerOptions?: SentryHandleOptions): Handle {
- const options: Required<SentryHandleOptions> = {
- handleUnknownRoutes: false,
-injectFetchProxyScript: true,
- ...handlerOptions,
+ const { handleUnknownRoutes, ...rest } = handlerOptions ?? {};
+const options = {
+handleUnknownRoutes: handleUnknownRoutes ?? false,
+ ...rest,
  };
 
  const sentryRequestHandler: Handle = input => {
@@ -131,12 +131,24 @@ export function sentryHandle(handlerOptions?: SentryHandleOptions): Handle {
 
 async function instrumentHandle(
  { event, resolve }: Parameters<Handle>[0],
- options: Required<SentryHandleOptions>,
+ options: SentryHandleOptions,
 ): Promise<Response> {
  if (!event.route?.id && !options.handleUnknownRoutes) {
  return resolve(event);
  }
 
+ // caching the result of the version check in `options.injectFetchProxyScript`
+ // to avoid doing the dynamic import on every request
+ if (options.injectFetchProxyScript == null) {
+ try {
+ // @ts-expect-error - the dynamic import is fine here
+ const { VERSION } = await import('@sveltejs/kit');
+ options.injectFetchProxyScript = isFetchProxyRequired(VERSION);
+ } catch {
+ options.injectFetchProxyScript = true;
+ }
+ }
+
  const routeName = `${event.request.method} ${event.route?.id || event.url.pathname}`;
 
  if (getIsolationScope() !== getDefaultIsolationScope()) {
@@ -161,7 +173,7 @@ async function instrumentHandle(
  normalizedRequest: winterCGRequestToRequestData(event.request.clone()),
  });
  const res = await resolve(event, {
- transformPageChunk: addSentryCodeToPage({ injectFetchProxyScript: options.injectFetchProxyScript }),
+ transformPageChunk: addSentryCodeToPage({ injectFetchProxyScript: options.injectFetchProxyScript ?? true }),
  });
  if (span) {
  setHttpStatus(span, res.status);
@@ -177,3 +189,19 @@ async function instrumentHandle(
  await flushIfServerless();
  }
 }
+
+/**
+ * We only need to inject the fetch proxy script for SvelteKit versions < 2.16.0.
+ * Exported only for testing.
+ */
+export function isFetchProxyRequired(version: string): boolean {
+ try {
+ const [major, minor] = version.trim().replace(/-.*/, '').split('.').map(Number);
+ if (major != null && minor != null && (major > 2 || (major === 2 && minor >= 16))) {
+ return false;
+ }
+ } catch {
+ // ignore
+ }
+ return true;
+}

packages/sveltekit/test/server/handle.test.ts

@@ -14,7 +14,7 @@ import type { Handle } from '@sveltejs/kit';
 import { redirect } from '@sveltejs/kit';
 import { vi } from 'vitest';
 
-import { FETCH_PROXY_SCRIPT, addSentryCodeToPage, sentryHandle } from '../../src/server/handle';
+import { FETCH_PROXY_SCRIPT, addSentryCodeToPage, isFetchProxyRequired, sentryHandle } from '../../src/server/handle';
 import { getDefaultNodeClientOptions } from '../utils';
 
 const mockCaptureException = vi.spyOn(SentryNode, 'captureException').mockImplementation(() => 'xx');
@@ -462,3 +462,20 @@ describe('addSentryCodeToPage', () => {
  expect(transformed).not.toContain(`<script >${FETCH_PROXY_SCRIPT}</script>`);
  });
 });
+
+describe('isFetchProxyRequired', () => {
+ it.each(['2.16.0', '2.16.1', '2.17.0', '3.0.0', '3.0.0-alpha.0'])(
+ 'returns false if the version is greater than or equal to 2.16.0 (%s)',
+ version => {
+ expect(isFetchProxyRequired(version)).toBe(false);
+ },
+ );
+
+ it.each(['2.15.0', '2.15.1', '1.30.0', '1.0.0'])('returns true if the version is lower than 2.16.0 (%s)', version => {
+ expect(isFetchProxyRequired(version)).toBe(true);
+ });
+
+ it.each(['invalid', 'a.b.c'])('returns true for an invalid version (%s)', version => {
+ expect(isFetchProxyRequired(version)).toBe(true);
+ });
+});

dev-packages/e2e-tests/test-applications/sveltekit-2-twp/package.json → dev-packages/e2e-tests/test-applications/sveltekit-2.5.0-twp/package.json

@@ -1,5 +1,5 @@
 {
- "name": "sveltekit-2-svelte-5",
+ "name": "sveltekit-2.5.0-twp",
  "version": "0.0.1",
  "private": true,
  "scripts": {
@@ -22,7 +22,7 @@
  "@sentry-internal/test-utils": "link:../../../test-utils",
  "@sentry/core": "latest || *",
  "@sveltejs/adapter-auto": "^3.0.0",
- "@sveltejs/kit": "^2.0.0",
+ "@sveltejs/kit": "2.5.0",
  "@sveltejs/vite-plugin-svelte": "^3.0.0",
  "svelte": "^5.0.0-next.115",
  "svelte-check": "^3.6.0",

dev-packages/e2e-tests/test-applications/sveltekit-2-twp/start-event-proxy.mjs → dev-packages/e2e-tests/test-applications/sveltekit-2.5.0-twp/start-event-proxy.mjs

@@ -2,5 +2,5 @@ import { startEventProxyServer } from '@sentry-internal/test-utils';
 
 startEventProxyServer({
  port: 3031,
- proxyServerName: 'sveltekit-2-twp',
+ proxyServerName: 'sveltekit-2.5.0-twp',
 });

dev-packages/e2e-tests/test-applications/sveltekit-2-twp/tests/errors.test.ts → dev-packages/e2e-tests/test-applications/sveltekit-2.5.0-twp/tests/errors.test.ts

@@ -2,11 +2,11 @@ import { expect, test } from '@playwright/test';
 import { waitForError } from '@sentry-internal/test-utils';
 
 test('errors on frontend and backend are connected by the same trace', async ({ page }) => {
- const clientErrorPromise = waitForError('sveltekit-2-twp', evt => {
+ const clientErrorPromise = waitForError('sveltekit-2.5.0-twp', evt => {
  return evt.exception?.values?.[0].value === 'Client Error';
  });
 
- const serverErrorPromise = waitForError('sveltekit-2-twp', evt => {
+ const serverErrorPromise = waitForError('sveltekit-2.5.0-twp', evt => {
  return evt.exception?.values?.[0].value === 'No search query provided';
  });
 

dev-packages/e2e-tests/test-applications/sveltekit-2.5.0-twp/tests/sdk.test.ts

@@ -0,0 +1,16 @@
+import { expect, test } from '@playwright/test';
+
+test.describe('SDK-internal behavior', () => {
+ test('Injects fetch proxy script for SvelteKit<2.16.0', async ({ page }) => {
+ await page.goto('/');
+
+ const sentryCarrier = await page.evaluate('typeof window.__SENTRY__');
+ const proxyHandle = await page.evaluate('typeof window._sentryFetchProxy');
+
+ // sanity check
+ expect(sentryCarrier).toBe('object');
+
+ // fetch proxy script ran
+ expect(proxyHandle).toBe('function');
+ });
+});

dev-packages/e2e-tests/test-applications/sveltekit-2/package.json

@@ -23,7 +23,7 @@
  "@sentry/core": "latest || *",
  "@sveltejs/adapter-auto": "^3.0.0",
  "@sveltejs/adapter-node": "^2.0.0",
- "@sveltejs/kit": "^2.5.0",
+ "@sveltejs/kit": "^2.16.0",
  "@sveltejs/vite-plugin-svelte": "^3.0.0",
  "svelte": "^4.2.8",
  "svelte-check": "^3.6.0",

dev-packages/e2e-tests/test-applications/sveltekit-2/tests/sdk.test.ts

@@ -0,0 +1,16 @@
+import { expect, test } from '@playwright/test';
+import { waitForInitialPageload } from './utils';
+
+test.describe('SDK-internal behavior', () => {
+ test("Doesn't inject fetch proxy script for SvelteKit>=2.16.0", async ({ page }) => {
+ await waitForInitialPageload(page, { route: '/' });
+ const sentryCarrier = await page.evaluate('typeof window.__SENTRY__');
+ const proxyHandle = await page.evaluate('typeof window._sentryFetchProxy');
+
+ // sanity check
+ expect(sentryCarrier).toBe('object');
+
+ // fetch proxy script didn't run
+ expect(proxyHandle).toBe('undefined');
+ });
+});

packages/sveltekit/package.json

@@ -9,9 +9,7 @@
  "engines": {
  "node": ">=18"
  },
- "files": [
- "/build"
- ],
+ "files": ["/build"],
  "main": "build/cjs/index.server.js",
  "module": "build/esm/index.server.js",
  "browser": "build/esm/index.client.js",

packages/sveltekit/src/server/handle.ts

@@ -93,10 +93,10 @@ export function addSentryCodeToPage(options: { injectFetchProxyScript: boolean }
  * ```
  */
 export function sentryHandle(handlerOptions?: SentryHandleOptions): Handle {
- const options: Required<SentryHandleOptions> = {
- handleUnknownRoutes: false,
-injectFetchProxyScript: true,
- ...handlerOptions,
+ const { handleUnknownRoutes, ...rest } = handlerOptions ?? {};
+const options = {
+handleUnknownRoutes: handleUnknownRoutes ?? false,
+ ...rest,
  };
 
  const sentryRequestHandler: Handle = input => {
@@ -131,12 +131,24 @@ export function sentryHandle(handlerOptions?: SentryHandleOptions): Handle {
 
 async function instrumentHandle(
  { event, resolve }: Parameters<Handle>[0],
- options: Required<SentryHandleOptions>,
+ options: SentryHandleOptions,
 ): Promise<Response> {
  if (!event.route?.id && !options.handleUnknownRoutes) {
  return resolve(event);
  }
 
+ // caching the result of the version check in `options.injectFetchProxyScript`
+ // to avoid doing the dynamic import on every request
+ if (options.injectFetchProxyScript == null) {
+ try {
+ // @ts-expect-error - the dynamic import is fine here
+ const { VERSION } = await import('@sveltejs/kit');
+ options.injectFetchProxyScript = isFetchProxyRequired(VERSION);
+ } catch {
+ options.injectFetchProxyScript = true;
+ }
+ }
+
  const routeName = `${event.request.method} ${event.route?.id || event.url.pathname}`;
 
  if (getIsolationScope() !== getDefaultIsolationScope()) {
@@ -161,7 +173,7 @@ async function instrumentHandle(
  normalizedRequest: winterCGRequestToRequestData(event.request.clone()),
  });
  const res = await resolve(event, {
- transformPageChunk: addSentryCodeToPage({ injectFetchProxyScript: options.injectFetchProxyScript }),
+ transformPageChunk: addSentryCodeToPage({ injectFetchProxyScript: options.injectFetchProxyScript ?? true }),
  });
  if (span) {
  setHttpStatus(span, res.status);
@@ -177,3 +189,19 @@ async function instrumentHandle(
  await flushIfServerless();
  }
 }
+
+/**
+ * We only need to inject the fetch proxy script for SvelteKit versions < 2.16.0.
+ * Exported only for testing.
+ */
+export function isFetchProxyRequired(version: string): boolean {
+ try {
+ const [major, minor] = version.trim().replace(/-.*/, '').split('.').map(Number);
+ if (major != null && minor != null && (major > 2 || (major === 2 && minor >= 16))) {
+ return false;
+ }
+ } catch {
+ // ignore
+ }
+ return true;
+}

packages/sveltekit/test/server/handle.test.ts

@@ -14,7 +14,7 @@ import type { Handle } from '@sveltejs/kit';
 import { redirect } from '@sveltejs/kit';
 import { vi } from 'vitest';
 
-import { FETCH_PROXY_SCRIPT, addSentryCodeToPage, sentryHandle } from '../../src/server/handle';
+import { FETCH_PROXY_SCRIPT, addSentryCodeToPage, isFetchProxyRequired, sentryHandle } from '../../src/server/handle';
 import { getDefaultNodeClientOptions } from '../utils';
 
 const mockCaptureException = vi.spyOn(SentryNode, 'captureException').mockImplementation(() => 'xx');
@@ -462,3 +462,20 @@ describe('addSentryCodeToPage', () => {
  expect(transformed).not.toContain(`<script >${FETCH_PROXY_SCRIPT}</script>`);
  });
 });
+
+describe('isFetchProxyRequired', () => {
+ it.each(['2.16.0', '2.16.1', '2.17.0', '3.0.0', '3.0.0-alpha.0'])(
+ 'returns false if the version is greater than or equal to 2.16.0 (%s)',
+ version => {
+ expect(isFetchProxyRequired(version)).toBe(false);
+ },
+ );
+
+ it.each(['2.15.0', '2.15.1', '1.30.0', '1.0.0'])('returns true if the version is lower than 2.16.0 (%s)', version => {
+ expect(isFetchProxyRequired(version)).toBe(true);
+ });
+
+ it.each(['invalid', 'a.b.c'])('returns true for an invalid version (%s)', version => {
+ expect(isFetchProxyRequired(version)).toBe(true);
+ });
+});

dev-packages/e2e-tests/test-applications/sveltekit-2-twp/package.json → dev-packages/e2e-tests/test-applications/sveltekit-2.5.0-twp/package.json

@@ -1,5 +1,5 @@
 {
- "name": "sveltekit-2-svelte-5",
+ "name": "sveltekit-2.5.0-twp",
  "version": "0.0.1",
  "private": true,
  "scripts": {
@@ -22,7 +22,7 @@
  "@sentry-internal/test-utils": "link:../../../test-utils",
  "@sentry/core": "latest || *",
  "@sveltejs/adapter-auto": "^3.0.0",
- "@sveltejs/kit": "^2.0.0",
+ "@sveltejs/kit": "2.5.0",
  "@sveltejs/vite-plugin-svelte": "^3.0.0",
  "svelte": "^5.0.0-next.115",
  "svelte-check": "^3.6.0",

dev-packages/e2e-tests/test-applications/sveltekit-2-twp/start-event-proxy.mjs → dev-packages/e2e-tests/test-applications/sveltekit-2.5.0-twp/start-event-proxy.mjs

@@ -2,5 +2,5 @@ import { startEventProxyServer } from '@sentry-internal/test-utils';
 
 startEventProxyServer({
  port: 3031,
- proxyServerName: 'sveltekit-2-twp',
+ proxyServerName: 'sveltekit-2.5.0-twp',
 });

dev-packages/e2e-tests/test-applications/sveltekit-2-twp/tests/errors.test.ts → dev-packages/e2e-tests/test-applications/sveltekit-2.5.0-twp/tests/errors.test.ts

@@ -2,11 +2,11 @@ import { expect, test } from '@playwright/test';
 import { waitForError } from '@sentry-internal/test-utils';
 
 test('errors on frontend and backend are connected by the same trace', async ({ page }) => {
- const clientErrorPromise = waitForError('sveltekit-2-twp', evt => {
+ const clientErrorPromise = waitForError('sveltekit-2.5.0-twp', evt => {
  return evt.exception?.values?.[0].value === 'Client Error';
  });
 
- const serverErrorPromise = waitForError('sveltekit-2-twp', evt => {
+ const serverErrorPromise = waitForError('sveltekit-2.5.0-twp', evt => {
  return evt.exception?.values?.[0].value === 'No search query provided';
  });
 

dev-packages/e2e-tests/test-applications/sveltekit-2.5.0-twp/tests/sdk.test.ts

@@ -0,0 +1,16 @@
+import { expect, test } from '@playwright/test';
+
+test.describe('SDK-internal behavior', () => {
+ test('Injects fetch proxy script for SvelteKit<2.16.0', async ({ page }) => {
+ await page.goto('/');
+
+ const sentryCarrier = await page.evaluate('typeof window.__SENTRY__');
+ const proxyHandle = await page.evaluate('typeof window._sentryFetchProxy');
+
+ // sanity check
+ expect(sentryCarrier).toBe('object');
+
+ // fetch proxy script ran
+ expect(proxyHandle).toBe('function');
+ });
+});

dev-packages/e2e-tests/test-applications/sveltekit-2/package.json

@@ -23,7 +23,7 @@
  "@sentry/core": "latest || *",
  "@sveltejs/adapter-auto": "^3.0.0",
  "@sveltejs/adapter-node": "^2.0.0",
- "@sveltejs/kit": "^2.5.0",
+ "@sveltejs/kit": "^2.16.0",
  "@sveltejs/vite-plugin-svelte": "^3.0.0",
  "svelte": "^4.2.8",
  "svelte-check": "^3.6.0",

dev-packages/e2e-tests/test-applications/sveltekit-2/tests/sdk.test.ts

@@ -0,0 +1,16 @@
+import { expect, test } from '@playwright/test';
+import { waitForInitialPageload } from './utils';
+
+test.describe('SDK-internal behavior', () => {
+ test("Doesn't inject fetch proxy script for SvelteKit>=2.16.0", async ({ page }) => {
+ await waitForInitialPageload(page, { route: '/' });
+ const sentryCarrier = await page.evaluate('typeof window.__SENTRY__');
+ const proxyHandle = await page.evaluate('typeof window._sentryFetchProxy');
+
+ // sanity check
+ expect(sentryCarrier).toBe('object');
+
+ // fetch proxy script didn't run
+ expect(proxyHandle).toBe('undefined');
+ });
+});

packages/sveltekit/package.json

@@ -9,9 +9,7 @@
  "engines": {
  "node": ">=18"
  },
- "files": [
- "/build"
- ],
+ "files": ["/build"],
  "main": "build/cjs/index.server.js",
  "module": "build/esm/index.server.js",
  "browser": "build/esm/index.client.js",

packages/sveltekit/src/server/handle.ts

@@ -93,10 +93,10 @@ export function addSentryCodeToPage(options: { injectFetchProxyScript: boolean }
  * ```
  */
 export function sentryHandle(handlerOptions?: SentryHandleOptions): Handle {
- const options: Required<SentryHandleOptions> = {
- handleUnknownRoutes: false,
-injectFetchProxyScript: true,
- ...handlerOptions,
+ const { handleUnknownRoutes, ...rest } = handlerOptions ?? {};
+const options = {
+handleUnknownRoutes: handleUnknownRoutes ?? false,
+ ...rest,
  };
 
  const sentryRequestHandler: Handle = input => {
@@ -131,12 +131,24 @@ export function sentryHandle(handlerOptions?: SentryHandleOptions): Handle {
 
 async function instrumentHandle(
  { event, resolve }: Parameters<Handle>[0],
- options: Required<SentryHandleOptions>,
+ options: SentryHandleOptions,
 ): Promise<Response> {
  if (!event.route?.id && !options.handleUnknownRoutes) {
  return resolve(event);
  }
 
+ // caching the result of the version check in `options.injectFetchProxyScript`
+ // to avoid doing the dynamic import on every request
+ if (options.injectFetchProxyScript == null) {
+ try {
+ // @ts-expect-error - the dynamic import is fine here
+ const { VERSION } = await import('@sveltejs/kit');
+ options.injectFetchProxyScript = isFetchProxyRequired(VERSION);
+ } catch {
+ options.injectFetchProxyScript = true;
+ }
+ }
+
  const routeName = `${event.request.method} ${event.route?.id || event.url.pathname}`;
 
  if (getIsolationScope() !== getDefaultIsolationScope()) {
@@ -161,7 +173,7 @@ async function instrumentHandle(
  normalizedRequest: winterCGRequestToRequestData(event.request.clone()),
  });
  const res = await resolve(event, {
- transformPageChunk: addSentryCodeToPage({ injectFetchProxyScript: options.injectFetchProxyScript }),
+ transformPageChunk: addSentryCodeToPage({ injectFetchProxyScript: options.injectFetchProxyScript ?? true }),
  });
  if (span) {
  setHttpStatus(span, res.status);
@@ -177,3 +189,19 @@ async function instrumentHandle(
  await flushIfServerless();
  }
 }
+
+/**
+ * We only need to inject the fetch proxy script for SvelteKit versions < 2.16.0.
+ * Exported only for testing.
+ */
+export function isFetchProxyRequired(version: string): boolean {
+ try {
+ const [major, minor] = version.trim().replace(/-.*/, '').split('.').map(Number);
+ if (major != null && minor != null && (major > 2 || (major === 2 && minor >= 16))) {
+ return false;
+ }
+ } catch {
+ // ignore
+ }
+ return true;
+}

packages/sveltekit/test/server/handle.test.ts

@@ -14,7 +14,7 @@ import type { Handle } from '@sveltejs/kit';
 import { redirect } from '@sveltejs/kit';
 import { vi } from 'vitest';
 
-import { FETCH_PROXY_SCRIPT, addSentryCodeToPage, sentryHandle } from '../../src/server/handle';
+import { FETCH_PROXY_SCRIPT, addSentryCodeToPage, isFetchProxyRequired, sentryHandle } from '../../src/server/handle';
 import { getDefaultNodeClientOptions } from '../utils';
 
 const mockCaptureException = vi.spyOn(SentryNode, 'captureException').mockImplementation(() => 'xx');
@@ -462,3 +462,20 @@ describe('addSentryCodeToPage', () => {
  expect(transformed).not.toContain(`<script >${FETCH_PROXY_SCRIPT}</script>`);
  });
 });
+
+describe('isFetchProxyRequired', () => {
+ it.each(['2.16.0', '2.16.1', '2.17.0', '3.0.0', '3.0.0-alpha.0'])(
+ 'returns false if the version is greater than or equal to 2.16.0 (%s)',
+ version => {
+ expect(isFetchProxyRequired(version)).toBe(false);
+ },
+ );
+
+ it.each(['2.15.0', '2.15.1', '1.30.0', '1.0.0'])('returns true if the version is lower than 2.16.0 (%s)', version => {
+ expect(isFetchProxyRequired(version)).toBe(true);
+ });
+
+ it.each(['invalid', 'a.b.c'])('returns true for an invalid version (%s)', version => {
+ expect(isFetchProxyRequired(version)).toBe(true);
+ });
+});

dev-packages/e2e-tests/test-applications/sveltekit-2-twp/package.json → dev-packages/e2e-tests/test-applications/sveltekit-2.5.0-twp/package.json

@@ -1,5 +1,5 @@
 {
- "name": "sveltekit-2-svelte-5",
+ "name": "sveltekit-2.5.0-twp",
  "version": "0.0.1",
  "private": true,
  "scripts": {
@@ -22,7 +22,7 @@
  "@sentry-internal/test-utils": "link:../../../test-utils",
  "@sentry/core": "latest || *",
  "@sveltejs/adapter-auto": "^3.0.0",
- "@sveltejs/kit": "^2.0.0",
+ "@sveltejs/kit": "2.5.0",
  "@sveltejs/vite-plugin-svelte": "^3.0.0",
  "svelte": "^5.0.0-next.115",
  "svelte-check": "^3.6.0",

dev-packages/e2e-tests/test-applications/sveltekit-2-twp/start-event-proxy.mjs → dev-packages/e2e-tests/test-applications/sveltekit-2.5.0-twp/start-event-proxy.mjs

@@ -2,5 +2,5 @@ import { startEventProxyServer } from '@sentry-internal/test-utils';
 
 startEventProxyServer({
  port: 3031,
- proxyServerName: 'sveltekit-2-twp',
+ proxyServerName: 'sveltekit-2.5.0-twp',
 });

dev-packages/e2e-tests/test-applications/sveltekit-2-twp/tests/errors.test.ts → dev-packages/e2e-tests/test-applications/sveltekit-2.5.0-twp/tests/errors.test.ts

@@ -2,11 +2,11 @@ import { expect, test } from '@playwright/test';
 import { waitForError } from '@sentry-internal/test-utils';
 
 test('errors on frontend and backend are connected by the same trace', async ({ page }) => {
- const clientErrorPromise = waitForError('sveltekit-2-twp', evt => {
+ const clientErrorPromise = waitForError('sveltekit-2.5.0-twp', evt => {
  return evt.exception?.values?.[0].value === 'Client Error';
  });
 
- const serverErrorPromise = waitForError('sveltekit-2-twp', evt => {
+ const serverErrorPromise = waitForError('sveltekit-2.5.0-twp', evt => {
  return evt.exception?.values?.[0].value === 'No search query provided';
  });
 

dev-packages/e2e-tests/test-applications/sveltekit-2.5.0-twp/tests/sdk.test.ts

@@ -0,0 +1,16 @@
+import { expect, test } from '@playwright/test';
+
+test.describe('SDK-internal behavior', () => {
+ test('Injects fetch proxy script for SvelteKit<2.16.0', async ({ page }) => {
+ await page.goto('/');
+
+ const sentryCarrier = await page.evaluate('typeof window.__SENTRY__');
+ const proxyHandle = await page.evaluate('typeof window._sentryFetchProxy');
+
+ // sanity check
+ expect(sentryCarrier).toBe('object');
+
+ // fetch proxy script ran
+ expect(proxyHandle).toBe('function');
+ });
+});

dev-packages/e2e-tests/test-applications/sveltekit-2/package.json

@@ -23,7 +23,7 @@
  "@sentry/core": "latest || *",
  "@sveltejs/adapter-auto": "^3.0.0",
  "@sveltejs/adapter-node": "^2.0.0",
- "@sveltejs/kit": "^2.5.0",
+ "@sveltejs/kit": "^2.16.0",
  "@sveltejs/vite-plugin-svelte": "^3.0.0",
  "svelte": "^4.2.8",
  "svelte-check": "^3.6.0",

dev-packages/e2e-tests/test-applications/sveltekit-2/tests/sdk.test.ts

@@ -0,0 +1,16 @@
+import { expect, test } from '@playwright/test';
+import { waitForInitialPageload } from './utils';
+
+test.describe('SDK-internal behavior', () => {
+ test("Doesn't inject fetch proxy script for SvelteKit>=2.16.0", async ({ page }) => {
+ await waitForInitialPageload(page, { route: '/' });
+ const sentryCarrier = await page.evaluate('typeof window.__SENTRY__');
+ const proxyHandle = await page.evaluate('typeof window._sentryFetchProxy');
+
+ // sanity check
+ expect(sentryCarrier).toBe('object');
+
+ // fetch proxy script didn't run
+ expect(proxyHandle).toBe('undefined');
+ });
+});

packages/sveltekit/package.json

@@ -9,9 +9,7 @@
  "engines": {
  "node": ">=18"
  },
- "files": [
- "/build"
- ],
+ "files": ["/build"],
  "main": "build/cjs/index.server.js",
  "module": "build/esm/index.server.js",
  "browser": "build/esm/index.client.js",

packages/sveltekit/src/server/handle.ts

@@ -93,10 +93,10 @@ export function addSentryCodeToPage(options: { injectFetchProxyScript: boolean }
  * ```
  */
 export function sentryHandle(handlerOptions?: SentryHandleOptions): Handle {
- const options: Required<SentryHandleOptions> = {
- handleUnknownRoutes: false,
-injectFetchProxyScript: true,
- ...handlerOptions,
+ const { handleUnknownRoutes, ...rest } = handlerOptions ?? {};
+const options = {
+handleUnknownRoutes: handleUnknownRoutes ?? false,
+ ...rest,
  };
 
  const sentryRequestHandler: Handle = input => {
@@ -131,12 +131,24 @@ export function sentryHandle(handlerOptions?: SentryHandleOptions): Handle {
 
 async function instrumentHandle(
  { event, resolve }: Parameters<Handle>[0],
- options: Required<SentryHandleOptions>,
+ options: SentryHandleOptions,
 ): Promise<Response> {
  if (!event.route?.id && !options.handleUnknownRoutes) {
  return resolve(event);
  }
 
+ // caching the result of the version check in `options.injectFetchProxyScript`
+ // to avoid doing the dynamic import on every request
+ if (options.injectFetchProxyScript == null) {
+ try {
+ // @ts-expect-error - the dynamic import is fine here
+ const { VERSION } = await import('@sveltejs/kit');
+ options.injectFetchProxyScript = isFetchProxyRequired(VERSION);
+ } catch {
+ options.injectFetchProxyScript = true;
+ }
+ }
+
  const routeName = `${event.request.method} ${event.route?.id || event.url.pathname}`;
 
  if (getIsolationScope() !== getDefaultIsolationScope()) {
@@ -161,7 +173,7 @@ async function instrumentHandle(
  normalizedRequest: winterCGRequestToRequestData(event.request.clone()),
  });
  const res = await resolve(event, {
- transformPageChunk: addSentryCodeToPage({ injectFetchProxyScript: options.injectFetchProxyScript }),
+ transformPageChunk: addSentryCodeToPage({ injectFetchProxyScript: options.injectFetchProxyScript ?? true }),
  });
  if (span) {
  setHttpStatus(span, res.status);
@@ -177,3 +189,19 @@ async function instrumentHandle(
  await flushIfServerless();
  }
 }
+
+/**
+ * We only need to inject the fetch proxy script for SvelteKit versions < 2.16.0.
+ * Exported only for testing.
+ */
+export function isFetchProxyRequired(version: string): boolean {
+ try {
+ const [major, minor] = version.trim().replace(/-.*/, '').split('.').map(Number);
+ if (major != null && minor != null && (major > 2 || (major === 2 && minor >= 16))) {
+ return false;
+ }
+ } catch {
+ // ignore
+ }
+ return true;
+}

packages/sveltekit/test/server/handle.test.ts

@@ -14,7 +14,7 @@ import type { Handle } from '@sveltejs/kit';
 import { redirect } from '@sveltejs/kit';
 import { vi } from 'vitest';
 
-import { FETCH_PROXY_SCRIPT, addSentryCodeToPage, sentryHandle } from '../../src/server/handle';
+import { FETCH_PROXY_SCRIPT, addSentryCodeToPage, isFetchProxyRequired, sentryHandle } from '../../src/server/handle';
 import { getDefaultNodeClientOptions } from '../utils';
 
 const mockCaptureException = vi.spyOn(SentryNode, 'captureException').mockImplementation(() => 'xx');
@@ -462,3 +462,20 @@ describe('addSentryCodeToPage', () => {
  expect(transformed).not.toContain(`<script >${FETCH_PROXY_SCRIPT}</script>`);
  });
 });
+
+describe('isFetchProxyRequired', () => {
+ it.each(['2.16.0', '2.16.1', '2.17.0', '3.0.0', '3.0.0-alpha.0'])(
+ 'returns false if the version is greater than or equal to 2.16.0 (%s)',
+ version => {
+ expect(isFetchProxyRequired(version)).toBe(false);
+ },
+ );
+
+ it.each(['2.15.0', '2.15.1', '1.30.0', '1.0.0'])('returns true if the version is lower than 2.16.0 (%s)', version => {
+ expect(isFetchProxyRequired(version)).toBe(true);
+ });
+
+ it.each(['invalid', 'a.b.c'])('returns true for an invalid version (%s)', version => {
+ expect(isFetchProxyRequired(version)).toBe(true);
+ });
+});

dev-packages/e2e-tests/test-applications/sveltekit-2-twp/package.json → dev-packages/e2e-tests/test-applications/sveltekit-2.5.0-twp/package.json

@@ -1,5 +1,5 @@
 {
- "name": "sveltekit-2-svelte-5",
+ "name": "sveltekit-2.5.0-twp",
  "version": "0.0.1",
  "private": true,
  "scripts": {
@@ -22,7 +22,7 @@
  "@sentry-internal/test-utils": "link:../../../test-utils",
  "@sentry/core": "latest || *",
  "@sveltejs/adapter-auto": "^3.0.0",
- "@sveltejs/kit": "^2.0.0",
+ "@sveltejs/kit": "2.5.0",
  "@sveltejs/vite-plugin-svelte": "^3.0.0",
  "svelte": "^5.0.0-next.115",
  "svelte-check": "^3.6.0",

dev-packages/e2e-tests/test-applications/sveltekit-2-twp/start-event-proxy.mjs → dev-packages/e2e-tests/test-applications/sveltekit-2.5.0-twp/start-event-proxy.mjs

@@ -2,5 +2,5 @@ import { startEventProxyServer } from '@sentry-internal/test-utils';
 
 startEventProxyServer({
  port: 3031,
- proxyServerName: 'sveltekit-2-twp',
+ proxyServerName: 'sveltekit-2.5.0-twp',
 });

dev-packages/e2e-tests/test-applications/sveltekit-2-twp/tests/errors.test.ts → dev-packages/e2e-tests/test-applications/sveltekit-2.5.0-twp/tests/errors.test.ts

@@ -2,11 +2,11 @@ import { expect, test } from '@playwright/test';
 import { waitForError } from '@sentry-internal/test-utils';
 
 test('errors on frontend and backend are connected by the same trace', async ({ page }) => {
- const clientErrorPromise = waitForError('sveltekit-2-twp', evt => {
+ const clientErrorPromise = waitForError('sveltekit-2.5.0-twp', evt => {
  return evt.exception?.values?.[0].value === 'Client Error';
  });
 
- const serverErrorPromise = waitForError('sveltekit-2-twp', evt => {
+ const serverErrorPromise = waitForError('sveltekit-2.5.0-twp', evt => {
  return evt.exception?.values?.[0].value === 'No search query provided';
  });
 

dev-packages/e2e-tests/test-applications/sveltekit-2.5.0-twp/tests/sdk.test.ts

@@ -0,0 +1,16 @@
+import { expect, test } from '@playwright/test';
+
+test.describe('SDK-internal behavior', () => {
+ test('Injects fetch proxy script for SvelteKit<2.16.0', async ({ page }) => {
+ await page.goto('/');
+
+ const sentryCarrier = await page.evaluate('typeof window.__SENTRY__');
+ const proxyHandle = await page.evaluate('typeof window._sentryFetchProxy');
+
+ // sanity check
+ expect(sentryCarrier).toBe('object');
+
+ // fetch proxy script ran
+ expect(proxyHandle).toBe('function');
+ });
+});

dev-packages/e2e-tests/test-applications/sveltekit-2/package.json

@@ -23,7 +23,7 @@
  "@sentry/core": "latest || *",
  "@sveltejs/adapter-auto": "^3.0.0",
  "@sveltejs/adapter-node": "^2.0.0",
- "@sveltejs/kit": "^2.5.0",
+ "@sveltejs/kit": "^2.16.0",
  "@sveltejs/vite-plugin-svelte": "^3.0.0",
  "svelte": "^4.2.8",
  "svelte-check": "^3.6.0",

dev-packages/e2e-tests/test-applications/sveltekit-2/tests/sdk.test.ts

@@ -0,0 +1,16 @@
+import { expect, test } from '@playwright/test';
+import { waitForInitialPageload } from './utils';
+
+test.describe('SDK-internal behavior', () => {
+ test("Doesn't inject fetch proxy script for SvelteKit>=2.16.0", async ({ page }) => {
+ await waitForInitialPageload(page, { route: '/' });
+ const sentryCarrier = await page.evaluate('typeof window.__SENTRY__');
+ const proxyHandle = await page.evaluate('typeof window._sentryFetchProxy');
+
+ // sanity check
+ expect(sentryCarrier).toBe('object');
+
+ // fetch proxy script didn't run
+ expect(proxyHandle).toBe('undefined');
+ });
+});

packages/sveltekit/package.json

@@ -9,9 +9,7 @@
  "engines": {
  "node": ">=18"
  },
- "files": [
- "/build"
- ],
+ "files": ["/build"],
  "main": "build/cjs/index.server.js",
  "module": "build/esm/index.server.js",
  "browser": "build/esm/index.client.js",

packages/sveltekit/src/server/handle.ts

@@ -93,10 +93,10 @@ export function addSentryCodeToPage(options: { injectFetchProxyScript: boolean }
  * ```
  */
 export function sentryHandle(handlerOptions?: SentryHandleOptions): Handle {
- const options: Required<SentryHandleOptions> = {
- handleUnknownRoutes: false,
-injectFetchProxyScript: true,
- ...handlerOptions,
+ const { handleUnknownRoutes, ...rest } = handlerOptions ?? {};
+const options = {
+handleUnknownRoutes: handleUnknownRoutes ?? false,
+ ...rest,
  };
 
  const sentryRequestHandler: Handle = input => {
@@ -131,12 +131,24 @@ export function sentryHandle(handlerOptions?: SentryHandleOptions): Handle {
 
 async function instrumentHandle(
  { event, resolve }: Parameters<Handle>[0],
- options: Required<SentryHandleOptions>,
+ options: SentryHandleOptions,
 ): Promise<Response> {
  if (!event.route?.id && !options.handleUnknownRoutes) {
  return resolve(event);
  }
 
+ // caching the result of the version check in `options.injectFetchProxyScript`
+ // to avoid doing the dynamic import on every request
+ if (options.injectFetchProxyScript == null) {
+ try {
+ // @ts-expect-error - the dynamic import is fine here
+ const { VERSION } = await import('@sveltejs/kit');
+ options.injectFetchProxyScript = isFetchProxyRequired(VERSION);
+ } catch {
+ options.injectFetchProxyScript = true;
+ }
+ }
+
  const routeName = `${event.request.method} ${event.route?.id || event.url.pathname}`;
 
  if (getIsolationScope() !== getDefaultIsolationScope()) {
@@ -161,7 +173,7 @@ async function instrumentHandle(
  normalizedRequest: winterCGRequestToRequestData(event.request.clone()),
  });
  const res = await resolve(event, {
- transformPageChunk: addSentryCodeToPage({ injectFetchProxyScript: options.injectFetchProxyScript }),
+ transformPageChunk: addSentryCodeToPage({ injectFetchProxyScript: options.injectFetchProxyScript ?? true }),
  });
  if (span) {
  setHttpStatus(span, res.status);
@@ -177,3 +189,19 @@ async function instrumentHandle(
  await flushIfServerless();
  }
 }
+
+/**
+ * We only need to inject the fetch proxy script for SvelteKit versions < 2.16.0.
+ * Exported only for testing.
+ */
+export function isFetchProxyRequired(version: string): boolean {
+ try {
+ const [major, minor] = version.trim().replace(/-.*/, '').split('.').map(Number);
+ if (major != null && minor != null && (major > 2 || (major === 2 && minor >= 16))) {
+ return false;
+ }
+ } catch {
+ // ignore
+ }
+ return true;
+}

packages/sveltekit/test/server/handle.test.ts

@@ -14,7 +14,7 @@ import type { Handle } from '@sveltejs/kit';
 import { redirect } from '@sveltejs/kit';
 import { vi } from 'vitest';
 
-import { FETCH_PROXY_SCRIPT, addSentryCodeToPage, sentryHandle } from '../../src/server/handle';
+import { FETCH_PROXY_SCRIPT, addSentryCodeToPage, isFetchProxyRequired, sentryHandle } from '../../src/server/handle';
 import { getDefaultNodeClientOptions } from '../utils';
 
 const mockCaptureException = vi.spyOn(SentryNode, 'captureException').mockImplementation(() => 'xx');
@@ -462,3 +462,20 @@ describe('addSentryCodeToPage', () => {
  expect(transformed).not.toContain(`<script >${FETCH_PROXY_SCRIPT}</script>`);
  });
 });
+
+describe('isFetchProxyRequired', () => {
+ it.each(['2.16.0', '2.16.1', '2.17.0', '3.0.0', '3.0.0-alpha.0'])(
+ 'returns false if the version is greater than or equal to 2.16.0 (%s)',
+ version => {
+ expect(isFetchProxyRequired(version)).toBe(false);
+ },
+ );
+
+ it.each(['2.15.0', '2.15.1', '1.30.0', '1.0.0'])('returns true if the version is lower than 2.16.0 (%s)', version => {
+ expect(isFetchProxyRequired(version)).toBe(true);
+ });
+
+ it.each(['invalid', 'a.b.c'])('returns true for an invalid version (%s)', version => {
+ expect(isFetchProxyRequired(version)).toBe(true);
+ });
+});

dev-packages/e2e-tests/test-applications/sveltekit-2-twp/package.json → dev-packages/e2e-tests/test-applications/sveltekit-2.5.0-twp/package.json

@@ -1,5 +1,5 @@
 {
- "name": "sveltekit-2-svelte-5",
+ "name": "sveltekit-2.5.0-twp",
  "version": "0.0.1",
  "private": true,
  "scripts": {
@@ -22,7 +22,7 @@
  "@sentry-internal/test-utils": "link:../../../test-utils",
  "@sentry/core": "latest || *",
  "@sveltejs/adapter-auto": "^3.0.0",
- "@sveltejs/kit": "^2.0.0",
+ "@sveltejs/kit": "2.5.0",
  "@sveltejs/vite-plugin-svelte": "^3.0.0",
  "svelte": "^5.0.0-next.115",
  "svelte-check": "^3.6.0",

dev-packages/e2e-tests/test-applications/sveltekit-2-twp/start-event-proxy.mjs → dev-packages/e2e-tests/test-applications/sveltekit-2.5.0-twp/start-event-proxy.mjs

@@ -2,5 +2,5 @@ import { startEventProxyServer } from '@sentry-internal/test-utils';
 
 startEventProxyServer({
  port: 3031,
- proxyServerName: 'sveltekit-2-twp',
+ proxyServerName: 'sveltekit-2.5.0-twp',
 });

dev-packages/e2e-tests/test-applications/sveltekit-2-twp/tests/errors.test.ts → dev-packages/e2e-tests/test-applications/sveltekit-2.5.0-twp/tests/errors.test.ts

@@ -2,11 +2,11 @@ import { expect, test } from '@playwright/test';
 import { waitForError } from '@sentry-internal/test-utils';
 
 test('errors on frontend and backend are connected by the same trace', async ({ page }) => {
- const clientErrorPromise = waitForError('sveltekit-2-twp', evt => {
+ const clientErrorPromise = waitForError('sveltekit-2.5.0-twp', evt => {
  return evt.exception?.values?.[0].value === 'Client Error';
  });
 
- const serverErrorPromise = waitForError('sveltekit-2-twp', evt => {
+ const serverErrorPromise = waitForError('sveltekit-2.5.0-twp', evt => {
  return evt.exception?.values?.[0].value === 'No search query provided';
  });
 

dev-packages/e2e-tests/test-applications/sveltekit-2.5.0-twp/tests/sdk.test.ts

@@ -0,0 +1,16 @@
+import { expect, test } from '@playwright/test';
+
+test.describe('SDK-internal behavior', () => {
+ test('Injects fetch proxy script for SvelteKit<2.16.0', async ({ page }) => {
+ await page.goto('/');
+
+ const sentryCarrier = await page.evaluate('typeof window.__SENTRY__');
+ const proxyHandle = await page.evaluate('typeof window._sentryFetchProxy');
+
+ // sanity check
+ expect(sentryCarrier).toBe('object');
+
+ // fetch proxy script ran
+ expect(proxyHandle).toBe('function');
+ });
+});

dev-packages/e2e-tests/test-applications/sveltekit-2/package.json

@@ -23,7 +23,7 @@
  "@sentry/core": "latest || *",
  "@sveltejs/adapter-auto": "^3.0.0",
  "@sveltejs/adapter-node": "^2.0.0",
- "@sveltejs/kit": "^2.5.0",
+ "@sveltejs/kit": "^2.16.0",
  "@sveltejs/vite-plugin-svelte": "^3.0.0",
  "svelte": "^4.2.8",
  "svelte-check": "^3.6.0",

dev-packages/e2e-tests/test-applications/sveltekit-2/tests/sdk.test.ts

@@ -0,0 +1,16 @@
+import { expect, test } from '@playwright/test';
+import { waitForInitialPageload } from './utils';
+
+test.describe('SDK-internal behavior', () => {
+ test("Doesn't inject fetch proxy script for SvelteKit>=2.16.0", async ({ page }) => {
+ await waitForInitialPageload(page, { route: '/' });
+ const sentryCarrier = await page.evaluate('typeof window.__SENTRY__');
+ const proxyHandle = await page.evaluate('typeof window._sentryFetchProxy');
+
+ // sanity check
+ expect(sentryCarrier).toBe('object');
+
+ // fetch proxy script didn't run
+ expect(proxyHandle).toBe('undefined');
+ });
+});

packages/sveltekit/package.json

@@ -9,9 +9,7 @@
  "engines": {
  "node": ">=18"
  },
- "files": [
- "/build"
- ],
+ "files": ["/build"],
  "main": "build/cjs/index.server.js",
  "module": "build/esm/index.server.js",
  "browser": "build/esm/index.client.js",

packages/sveltekit/src/server/handle.ts

@@ -93,10 +93,10 @@ export function addSentryCodeToPage(options: { injectFetchProxyScript: boolean }
  * ```
  */
 export function sentryHandle(handlerOptions?: SentryHandleOptions): Handle {
- const options: Required<SentryHandleOptions> = {
- handleUnknownRoutes: false,
-injectFetchProxyScript: true,
- ...handlerOptions,
+ const { handleUnknownRoutes, ...rest } = handlerOptions ?? {};
+const options = {
+handleUnknownRoutes: handleUnknownRoutes ?? false,
+ ...rest,
  };
 
  const sentryRequestHandler: Handle = input => {
@@ -131,12 +131,24 @@ export function sentryHandle(handlerOptions?: SentryHandleOptions): Handle {
 
 async function instrumentHandle(
  { event, resolve }: Parameters<Handle>[0],
- options: Required<SentryHandleOptions>,
+ options: SentryHandleOptions,
 ): Promise<Response> {
  if (!event.route?.id && !options.handleUnknownRoutes) {
  return resolve(event);
  }
 
+ // caching the result of the version check in `options.injectFetchProxyScript`
+ // to avoid doing the dynamic import on every request
+ if (options.injectFetchProxyScript == null) {
+ try {
+ // @ts-expect-error - the dynamic import is fine here
+ const { VERSION } = await import('@sveltejs/kit');
+ options.injectFetchProxyScript = isFetchProxyRequired(VERSION);
+ } catch {
+ options.injectFetchProxyScript = true;
+ }
+ }
+
  const routeName = `${event.request.method} ${event.route?.id || event.url.pathname}`;
 
  if (getIsolationScope() !== getDefaultIsolationScope()) {
@@ -161,7 +173,7 @@ async function instrumentHandle(
  normalizedRequest: winterCGRequestToRequestData(event.request.clone()),
  });
  const res = await resolve(event, {
- transformPageChunk: addSentryCodeToPage({ injectFetchProxyScript: options.injectFetchProxyScript }),
+ transformPageChunk: addSentryCodeToPage({ injectFetchProxyScript: options.injectFetchProxyScript ?? true }),
  });
  if (span) {
  setHttpStatus(span, res.status);
@@ -177,3 +189,19 @@ async function instrumentHandle(
  await flushIfServerless();
  }
 }
+
+/**
+ * We only need to inject the fetch proxy script for SvelteKit versions < 2.16.0.
+ * Exported only for testing.
+ */
+export function isFetchProxyRequired(version: string): boolean {
+ try {
+ const [major, minor] = version.trim().replace(/-.*/, '').split('.').map(Number);
+ if (major != null && minor != null && (major > 2 || (major === 2 && minor >= 16))) {
+ return false;
+ }
+ } catch {
+ // ignore
+ }
+ return true;
+}

packages/sveltekit/test/server/handle.test.ts

@@ -14,7 +14,7 @@ import type { Handle } from '@sveltejs/kit';
 import { redirect } from '@sveltejs/kit';
 import { vi } from 'vitest';
 
-import { FETCH_PROXY_SCRIPT, addSentryCodeToPage, sentryHandle } from '../../src/server/handle';
+import { FETCH_PROXY_SCRIPT, addSentryCodeToPage, isFetchProxyRequired, sentryHandle } from '../../src/server/handle';
 import { getDefaultNodeClientOptions } from '../utils';
 
 const mockCaptureException = vi.spyOn(SentryNode, 'captureException').mockImplementation(() => 'xx');
@@ -462,3 +462,20 @@ describe('addSentryCodeToPage', () => {
  expect(transformed).not.toContain(`<script >${FETCH_PROXY_SCRIPT}</script>`);
  });
 });
+
+describe('isFetchProxyRequired', () => {
+ it.each(['2.16.0', '2.16.1', '2.17.0', '3.0.0', '3.0.0-alpha.0'])(
+ 'returns false if the version is greater than or equal to 2.16.0 (%s)',
+ version => {
+ expect(isFetchProxyRequired(version)).toBe(false);
+ },
+ );
+
+ it.each(['2.15.0', '2.15.1', '1.30.0', '1.0.0'])('returns true if the version is lower than 2.16.0 (%s)', version => {
+ expect(isFetchProxyRequired(version)).toBe(true);
+ });
+
+ it.each(['invalid', 'a.b.c'])('returns true for an invalid version (%s)', version => {
+ expect(isFetchProxyRequired(version)).toBe(true);
+ });
+});

dev-packages/e2e-tests/test-applications/sveltekit-2-twp/package.json → dev-packages/e2e-tests/test-applications/sveltekit-2.5.0-twp/package.json

@@ -1,5 +1,5 @@
 {
- "name": "sveltekit-2-svelte-5",
+ "name": "sveltekit-2.5.0-twp",
  "version": "0.0.1",
  "private": true,
  "scripts": {
@@ -22,7 +22,7 @@
  "@sentry-internal/test-utils": "link:../../../test-utils",
  "@sentry/core": "latest || *",
  "@sveltejs/adapter-auto": "^3.0.0",
- "@sveltejs/kit": "^2.0.0",
+ "@sveltejs/kit": "2.5.0",
  "@sveltejs/vite-plugin-svelte": "^3.0.0",
  "svelte": "^5.0.0-next.115",
  "svelte-check": "^3.6.0",

dev-packages/e2e-tests/test-applications/sveltekit-2-twp/start-event-proxy.mjs → dev-packages/e2e-tests/test-applications/sveltekit-2.5.0-twp/start-event-proxy.mjs

@@ -2,5 +2,5 @@ import { startEventProxyServer } from '@sentry-internal/test-utils';
 
 startEventProxyServer({
  port: 3031,
- proxyServerName: 'sveltekit-2-twp',
+ proxyServerName: 'sveltekit-2.5.0-twp',
 });

dev-packages/e2e-tests/test-applications/sveltekit-2-twp/tests/errors.test.ts → dev-packages/e2e-tests/test-applications/sveltekit-2.5.0-twp/tests/errors.test.ts

@@ -2,11 +2,11 @@ import { expect, test } from '@playwright/test';
 import { waitForError } from '@sentry-internal/test-utils';
 
 test('errors on frontend and backend are connected by the same trace', async ({ page }) => {
- const clientErrorPromise = waitForError('sveltekit-2-twp', evt => {
+ const clientErrorPromise = waitForError('sveltekit-2.5.0-twp', evt => {
  return evt.exception?.values?.[0].value === 'Client Error';
  });
 
- const serverErrorPromise = waitForError('sveltekit-2-twp', evt => {
+ const serverErrorPromise = waitForError('sveltekit-2.5.0-twp', evt => {
  return evt.exception?.values?.[0].value === 'No search query provided';
  });
 

dev-packages/e2e-tests/test-applications/sveltekit-2.5.0-twp/tests/sdk.test.ts

@@ -0,0 +1,16 @@
+import { expect, test } from '@playwright/test';
+
+test.describe('SDK-internal behavior', () => {
+ test('Injects fetch proxy script for SvelteKit<2.16.0', async ({ page }) => {
+ await page.goto('/');
+
+ const sentryCarrier = await page.evaluate('typeof window.__SENTRY__');
+ const proxyHandle = await page.evaluate('typeof window._sentryFetchProxy');
+
+ // sanity check
+ expect(sentryCarrier).toBe('object');
+
+ // fetch proxy script ran
+ expect(proxyHandle).toBe('function');
+ });
+});

dev-packages/e2e-tests/test-applications/sveltekit-2/package.json

@@ -23,7 +23,7 @@
  "@sentry/core": "latest || *",
  "@sveltejs/adapter-auto": "^3.0.0",
  "@sveltejs/adapter-node": "^2.0.0",
- "@sveltejs/kit": "^2.5.0",
+ "@sveltejs/kit": "^2.16.0",
  "@sveltejs/vite-plugin-svelte": "^3.0.0",
  "svelte": "^4.2.8",
  "svelte-check": "^3.6.0",

dev-packages/e2e-tests/test-applications/sveltekit-2/tests/sdk.test.ts

@@ -0,0 +1,16 @@
+import { expect, test } from '@playwright/test';
+import { waitForInitialPageload } from './utils';
+
+test.describe('SDK-internal behavior', () => {
+ test("Doesn't inject fetch proxy script for SvelteKit>=2.16.0", async ({ page }) => {
+ await waitForInitialPageload(page, { route: '/' });
+ const sentryCarrier = await page.evaluate('typeof window.__SENTRY__');
+ const proxyHandle = await page.evaluate('typeof window._sentryFetchProxy');
+
+ // sanity check
+ expect(sentryCarrier).toBe('object');
+
+ // fetch proxy script didn't run
+ expect(proxyHandle).toBe('undefined');
+ });
+});

packages/sveltekit/package.json

@@ -9,9 +9,7 @@
  "engines": {
  "node": ">=18"
  },
- "files": [
- "/build"
- ],
+ "files": ["/build"],
  "main": "build/cjs/index.server.js",
  "module": "build/esm/index.server.js",
  "browser": "build/esm/index.client.js",

packages/sveltekit/src/server/handle.ts

@@ -93,10 +93,10 @@ export function addSentryCodeToPage(options: { injectFetchProxyScript: boolean }
  * ```
  */
 export function sentryHandle(handlerOptions?: SentryHandleOptions): Handle {
- const options: Required<SentryHandleOptions> = {
- handleUnknownRoutes: false,
-injectFetchProxyScript: true,
- ...handlerOptions,
+ const { handleUnknownRoutes, ...rest } = handlerOptions ?? {};
+const options = {
+handleUnknownRoutes: handleUnknownRoutes ?? false,
+ ...rest,
  };
 
  const sentryRequestHandler: Handle = input => {
@@ -131,12 +131,24 @@ export function sentryHandle(handlerOptions?: SentryHandleOptions): Handle {
 
 async function instrumentHandle(
  { event, resolve }: Parameters<Handle>[0],
- options: Required<SentryHandleOptions>,
+ options: SentryHandleOptions,
 ): Promise<Response> {
  if (!event.route?.id && !options.handleUnknownRoutes) {
  return resolve(event);
  }
 
+ // caching the result of the version check in `options.injectFetchProxyScript`
+ // to avoid doing the dynamic import on every request
+ if (options.injectFetchProxyScript == null) {
+ try {
+ // @ts-expect-error - the dynamic import is fine here
+ const { VERSION } = await import('@sveltejs/kit');
+ options.injectFetchProxyScript = isFetchProxyRequired(VERSION);
+ } catch {
+ options.injectFetchProxyScript = true;
+ }
+ }
+
  const routeName = `${event.request.method} ${event.route?.id || event.url.pathname}`;
 
  if (getIsolationScope() !== getDefaultIsolationScope()) {
@@ -161,7 +173,7 @@ async function instrumentHandle(
  normalizedRequest: winterCGRequestToRequestData(event.request.clone()),
  });
  const res = await resolve(event, {
- transformPageChunk: addSentryCodeToPage({ injectFetchProxyScript: options.injectFetchProxyScript }),
+ transformPageChunk: addSentryCodeToPage({ injectFetchProxyScript: options.injectFetchProxyScript ?? true }),
  });
  if (span) {
  setHttpStatus(span, res.status);
@@ -177,3 +189,19 @@ async function instrumentHandle(
  await flushIfServerless();
  }
 }
+
+/**
+ * We only need to inject the fetch proxy script for SvelteKit versions < 2.16.0.
+ * Exported only for testing.
+ */
+export function isFetchProxyRequired(version: string): boolean {
+ try {
+ const [major, minor] = version.trim().replace(/-.*/, '').split('.').map(Number);
+ if (major != null && minor != null && (major > 2 || (major === 2 && minor >= 16))) {
+ return false;
+ }
+ } catch {
+ // ignore
+ }
+ return true;
+}

packages/sveltekit/test/server/handle.test.ts

@@ -14,7 +14,7 @@ import type { Handle } from '@sveltejs/kit';
 import { redirect } from '@sveltejs/kit';
 import { vi } from 'vitest';
 
-import { FETCH_PROXY_SCRIPT, addSentryCodeToPage, sentryHandle } from '../../src/server/handle';
+import { FETCH_PROXY_SCRIPT, addSentryCodeToPage, isFetchProxyRequired, sentryHandle } from '../../src/server/handle';
 import { getDefaultNodeClientOptions } from '../utils';
 
 const mockCaptureException = vi.spyOn(SentryNode, 'captureException').mockImplementation(() => 'xx');
@@ -462,3 +462,20 @@ describe('addSentryCodeToPage', () => {
  expect(transformed).not.toContain(`<script >${FETCH_PROXY_SCRIPT}</script>`);
  });
 });
+
+describe('isFetchProxyRequired', () => {
+ it.each(['2.16.0', '2.16.1', '2.17.0', '3.0.0', '3.0.0-alpha.0'])(
+ 'returns false if the version is greater than or equal to 2.16.0 (%s)',
+ version => {
+ expect(isFetchProxyRequired(version)).toBe(false);
+ },
+ );
+
+ it.each(['2.15.0', '2.15.1', '1.30.0', '1.0.0'])('returns true if the version is lower than 2.16.0 (%s)', version => {
+ expect(isFetchProxyRequired(version)).toBe(true);
+ });
+
+ it.each(['invalid', 'a.b.c'])('returns true for an invalid version (%s)', version => {
+ expect(isFetchProxyRequired(version)).toBe(true);
+ });
+});

dev-packages/e2e-tests/test-applications/sveltekit-2-twp/package.json → dev-packages/e2e-tests/test-applications/sveltekit-2.5.0-twp/package.json

@@ -1,5 +1,5 @@
 {
- "name": "sveltekit-2-svelte-5",
+ "name": "sveltekit-2.5.0-twp",
  "version": "0.0.1",
  "private": true,
  "scripts": {
@@ -22,7 +22,7 @@
  "@sentry-internal/test-utils": "link:../../../test-utils",
  "@sentry/core": "latest || *",
  "@sveltejs/adapter-auto": "^3.0.0",
- "@sveltejs/kit": "^2.0.0",
+ "@sveltejs/kit": "2.5.0",
  "@sveltejs/vite-plugin-svelte": "^3.0.0",
  "svelte": "^5.0.0-next.115",
  "svelte-check": "^3.6.0",

dev-packages/e2e-tests/test-applications/sveltekit-2-twp/start-event-proxy.mjs → dev-packages/e2e-tests/test-applications/sveltekit-2.5.0-twp/start-event-proxy.mjs

@@ -2,5 +2,5 @@ import { startEventProxyServer } from '@sentry-internal/test-utils';
 
 startEventProxyServer({
  port: 3031,
- proxyServerName: 'sveltekit-2-twp',
+ proxyServerName: 'sveltekit-2.5.0-twp',
 });

dev-packages/e2e-tests/test-applications/sveltekit-2-twp/tests/errors.test.ts → dev-packages/e2e-tests/test-applications/sveltekit-2.5.0-twp/tests/errors.test.ts

@@ -2,11 +2,11 @@ import { expect, test } from '@playwright/test';
 import { waitForError } from '@sentry-internal/test-utils';
 
 test('errors on frontend and backend are connected by the same trace', async ({ page }) => {
- const clientErrorPromise = waitForError('sveltekit-2-twp', evt => {
+ const clientErrorPromise = waitForError('sveltekit-2.5.0-twp', evt => {
  return evt.exception?.values?.[0].value === 'Client Error';
  });
 
- const serverErrorPromise = waitForError('sveltekit-2-twp', evt => {
+ const serverErrorPromise = waitForError('sveltekit-2.5.0-twp', evt => {
  return evt.exception?.values?.[0].value === 'No search query provided';
  });
 

dev-packages/e2e-tests/test-applications/sveltekit-2.5.0-twp/tests/sdk.test.ts

@@ -0,0 +1,16 @@
+import { expect, test } from '@playwright/test';
+
+test.describe('SDK-internal behavior', () => {
+ test('Injects fetch proxy script for SvelteKit<2.16.0', async ({ page }) => {
+ await page.goto('/');
+
+ const sentryCarrier = await page.evaluate('typeof window.__SENTRY__');
+ const proxyHandle = await page.evaluate('typeof window._sentryFetchProxy');
+
+ // sanity check
+ expect(sentryCarrier).toBe('object');
+
+ // fetch proxy script ran
+ expect(proxyHandle).toBe('function');
+ });
+});

dev-packages/e2e-tests/test-applications/sveltekit-2/package.json

@@ -23,7 +23,7 @@
  "@sentry/core": "latest || *",
  "@sveltejs/adapter-auto": "^3.0.0",
  "@sveltejs/adapter-node": "^2.0.0",
- "@sveltejs/kit": "^2.5.0",
+ "@sveltejs/kit": "^2.16.0",
  "@sveltejs/vite-plugin-svelte": "^3.0.0",
  "svelte": "^4.2.8",
  "svelte-check": "^3.6.0",

dev-packages/e2e-tests/test-applications/sveltekit-2/tests/sdk.test.ts

@@ -0,0 +1,16 @@
+import { expect, test } from '@playwright/test';
+import { waitForInitialPageload } from './utils';
+
+test.describe('SDK-internal behavior', () => {
+ test("Doesn't inject fetch proxy script for SvelteKit>=2.16.0", async ({ page }) => {
+ await waitForInitialPageload(page, { route: '/' });
+ const sentryCarrier = await page.evaluate('typeof window.__SENTRY__');
+ const proxyHandle = await page.evaluate('typeof window._sentryFetchProxy');
+
+ // sanity check
+ expect(sentryCarrier).toBe('object');
+
+ // fetch proxy script didn't run
+ expect(proxyHandle).toBe('undefined');
+ });
+});

packages/sveltekit/package.json

@@ -9,9 +9,7 @@
  "engines": {
  "node": ">=18"
  },
- "files": [
- "/build"
- ],
+ "files": ["/build"],
  "main": "build/cjs/index.server.js",
  "module": "build/esm/index.server.js",
  "browser": "build/esm/index.client.js",

packages/sveltekit/src/server/handle.ts

@@ -93,10 +93,10 @@ export function addSentryCodeToPage(options: { injectFetchProxyScript: boolean }
  * ```
  */
 export function sentryHandle(handlerOptions?: SentryHandleOptions): Handle {
- const options: Required<SentryHandleOptions> = {
- handleUnknownRoutes: false,
-injectFetchProxyScript: true,
- ...handlerOptions,
+ const { handleUnknownRoutes, ...rest } = handlerOptions ?? {};
+const options = {
+handleUnknownRoutes: handleUnknownRoutes ?? false,
+ ...rest,
  };
 
  const sentryRequestHandler: Handle = input => {
@@ -131,12 +131,24 @@ export function sentryHandle(handlerOptions?: SentryHandleOptions): Handle {
 
 async function instrumentHandle(
  { event, resolve }: Parameters<Handle>[0],
- options: Required<SentryHandleOptions>,
+ options: SentryHandleOptions,
 ): Promise<Response> {
  if (!event.route?.id && !options.handleUnknownRoutes) {
  return resolve(event);
  }
 
+ // caching the result of the version check in `options.injectFetchProxyScript`
+ // to avoid doing the dynamic import on every request
+ if (options.injectFetchProxyScript == null) {
+ try {
+ // @ts-expect-error - the dynamic import is fine here
+ const { VERSION } = await import('@sveltejs/kit');
+ options.injectFetchProxyScript = isFetchProxyRequired(VERSION);
+ } catch {
+ options.injectFetchProxyScript = true;
+ }
+ }
+
  const routeName = `${event.request.method} ${event.route?.id || event.url.pathname}`;
 
  if (getIsolationScope() !== getDefaultIsolationScope()) {
@@ -161,7 +173,7 @@ async function instrumentHandle(
  normalizedRequest: winterCGRequestToRequestData(event.request.clone()),
  });
  const res = await resolve(event, {
- transformPageChunk: addSentryCodeToPage({ injectFetchProxyScript: options.injectFetchProxyScript }),
+ transformPageChunk: addSentryCodeToPage({ injectFetchProxyScript: options.injectFetchProxyScript ?? true }),
  });
  if (span) {
  setHttpStatus(span, res.status);
@@ -177,3 +189,19 @@ async function instrumentHandle(
  await flushIfServerless();
  }
 }
+
+/**
+ * We only need to inject the fetch proxy script for SvelteKit versions < 2.16.0.
+ * Exported only for testing.
+ */
+export function isFetchProxyRequired(version: string): boolean {
+ try {
+ const [major, minor] = version.trim().replace(/-.*/, '').split('.').map(Number);
+ if (major != null && minor != null && (major > 2 || (major === 2 && minor >= 16))) {
+ return false;
+ }
+ } catch {
+ // ignore
+ }
+ return true;
+}

packages/sveltekit/test/server/handle.test.ts

@@ -14,7 +14,7 @@ import type { Handle } from '@sveltejs/kit';
 import { redirect } from '@sveltejs/kit';
 import { vi } from 'vitest';
 
-import { FETCH_PROXY_SCRIPT, addSentryCodeToPage, sentryHandle } from '../../src/server/handle';
+import { FETCH_PROXY_SCRIPT, addSentryCodeToPage, isFetchProxyRequired, sentryHandle } from '../../src/server/handle';
 import { getDefaultNodeClientOptions } from '../utils';
 
 const mockCaptureException = vi.spyOn(SentryNode, 'captureException').mockImplementation(() => 'xx');
@@ -462,3 +462,20 @@ describe('addSentryCodeToPage', () => {
  expect(transformed).not.toContain(`<script >${FETCH_PROXY_SCRIPT}</script>`);
  });
 });
+
+describe('isFetchProxyRequired', () => {
+ it.each(['2.16.0', '2.16.1', '2.17.0', '3.0.0', '3.0.0-alpha.0'])(
+ 'returns false if the version is greater than or equal to 2.16.0 (%s)',
+ version => {
+ expect(isFetchProxyRequired(version)).toBe(false);
+ },
+ );
+
+ it.each(['2.15.0', '2.15.1', '1.30.0', '1.0.0'])('returns true if the version is lower than 2.16.0 (%s)', version => {
+ expect(isFetchProxyRequired(version)).toBe(true);
+ });
+
+ it.each(['invalid', 'a.b.c'])('returns true for an invalid version (%s)', version => {
+ expect(isFetchProxyRequired(version)).toBe(true);
+ });
+});