feat(sveltekit): Add server-side handleError wrapper (#7411)

Author: AbhiPrasad

packages/sveltekit/src/client/handleError.ts

@@ -11,7 +11,7 @@ import type { HandleClientError, NavigationEvent } from '@sveltejs/kit';
  *
  * @param handleError The original SvelteKit error handler.
  */
-export function wrapHandleError(handleError: HandleClientError): HandleClientError {
+export function handleErrorWithSentry(handleError?: HandleClientError): HandleClientError {
   return (input: { error: unknown; event: NavigationEvent }): ReturnType<HandleClientError> => {
     captureException(input.error, scope => {
       scope.addEventProcessor(event => {
@@ -23,6 +23,8 @@ export function wrapHandleError(handleError: HandleClientError): HandleClientErr
       });
       return scope;
     });
-    return handleError(input);
+    if (handleError) {
+      return handleError(input);
+    }
   };
 }

packages/sveltekit/src/client/index.ts

@@ -1,7 +1,7 @@
 export * from '@sentry/svelte';
 
 export { init } from './sdk';
-export { wrapHandleError } from './handleError';
+export { handleErrorWithSentry } from './handleError';
 
 // Just here so that eslint is happy until we export more stuff here
 export const PLACEHOLDER_CLIENT = 'PLACEHOLDER';

packages/sveltekit/src/index.types.ts

@@ -8,13 +8,19 @@ export * from './config';
 export * from './server';
 
 import type { Integration, Options, StackParser } from '@sentry/types';
+// eslint-disable-next-line import/no-unresolved
+import type { HandleClientError, HandleServerError } from '@sveltejs/kit';
 
 import type * as clientSdk from './client';
 import type * as serverSdk from './server';
 
 /** Initializes Sentry SvelteKit SDK */
 export declare function init(options: Options | clientSdk.BrowserOptions | serverSdk.NodeOptions): void;
 
+export declare function handleErrorWithSentry<T extends HandleClientError | HandleServerError>(
+  handleError: T,
+): ReturnType<T>;
+
 // We export a merged Integrations object so that users can (at least typing-wise) use all integrations everywhere.
 export declare const Integrations: typeof clientSdk.Integrations & typeof serverSdk.Integrations;
 

packages/sveltekit/src/server/handleError.ts

@@ -0,0 +1,30 @@
+import { captureException } from '@sentry/node';
+import { addExceptionMechanism } from '@sentry/utils';
+// For now disable the import/no-unresolved rule, because we don't have a way to
+// tell eslint that we are only importing types from the @sveltejs/kit package without
+// adding a custom resolver, which will take too much time.
+// eslint-disable-next-line import/no-unresolved
+import type { HandleServerError, RequestEvent } from '@sveltejs/kit';
+
+/**
+ * Wrapper for the SvelteKit error handler that sends the error to Sentry.
+ *
+ * @param handleError The original SvelteKit error handler.
+ */
+export function handleErrorWithSentry(handleError?: HandleServerError): HandleServerError {
+  return (input: { error: unknown; event: RequestEvent }): ReturnType<HandleServerError> => {
+    captureException(input.error, scope => {
+      scope.addEventProcessor(event => {
+        addExceptionMechanism(event, {
+          type: 'sveltekit',
+          handled: false,
+        });
+        return event;
+      });
+      return scope;
+    });
+    if (handleError) {
+      return handleError(input);
+    }
+  };
+}

packages/sveltekit/src/server/index.ts

@@ -1,3 +1,4 @@
 export * from '@sentry/node';
 
 export { init } from './sdk';
+export { handleErrorWithSentry } from './handleError';

packages/sveltekit/test/client/handleError.test.ts

@@ -5,7 +5,7 @@ import { Scope } from '@sentry/svelte';
 // eslint-disable-next-line import/no-unresolved
 import type { HandleClientError, NavigationEvent } from '@sveltejs/kit';
 
-import { wrapHandleError } from '../../src/client/handleError';
+import { handleErrorWithSentry } from '../../src/client/handleError';
 
 const mockCaptureException = jest.fn();
 let mockScope = new Scope();
@@ -55,8 +55,18 @@ describe('handleError', () => {
     mockScope = new Scope();
   });
 
+  it('works when a handleError func is not provided', async () => {
+    const wrappedHandleError = handleErrorWithSentry();
+    const mockError = new Error('test');
+    const returnVal = await wrappedHandleError({ error: mockError, event: navigationEvent });
+
+    expect(returnVal).not.toBeDefined();
+    expect(mockCaptureException).toHaveBeenCalledTimes(1);
+    expect(mockCaptureException).toHaveBeenCalledWith(mockError, expect.any(Function));
+  });
+
   it('calls captureException', async () => {
-    const wrappedHandleError = wrapHandleError(handleError);
+    const wrappedHandleError = handleErrorWithSentry(handleError);
     const mockError = new Error('test');
     const returnVal = await wrappedHandleError({ error: mockError, event: navigationEvent });
 
@@ -71,7 +81,7 @@ describe('handleError', () => {
       return mockScope;
     });
 
-    const wrappedHandleError = wrapHandleError(handleError);
+    const wrappedHandleError = handleErrorWithSentry(handleError);
     const mockError = new Error('test');
     await wrappedHandleError({ error: mockError, event: navigationEvent });
 

packages/sveltekit/test/server/handleError.test.ts

@@ -0,0 +1,84 @@
+import { Scope } from '@sentry/node';
+// For now disable the import/no-unresolved rule, because we don't have a way to
+// tell eslint that we are only importing types from the @sveltejs/kit package without
+// adding a custom resolver, which will take too much time.
+// eslint-disable-next-line import/no-unresolved
+import type { HandleServerError, RequestEvent } from '@sveltejs/kit';
+
+import { handleErrorWithSentry } from '../../src/server/handleError';
+
+const mockCaptureException = jest.fn();
+let mockScope = new Scope();
+
+jest.mock('@sentry/node', () => {
+  const original = jest.requireActual('@sentry/core');
+  return {
+    ...original,
+    captureException: (err: unknown, cb: (arg0: unknown) => unknown) => {
+      cb(mockScope);
+      mockCaptureException(err, cb);
+      return original.captureException(err, cb);
+    },
+  };
+});
+
+const mockAddExceptionMechanism = jest.fn();
+
+jest.mock('@sentry/utils', () => {
+  const original = jest.requireActual('@sentry/utils');
+  return {
+    ...original,
+    addExceptionMechanism: (...args: unknown[]) => mockAddExceptionMechanism(...args),
+  };
+});
+
+function handleError(_input: { error: unknown; event: RequestEvent }): ReturnType<HandleServerError> {
+  return {
+    message: 'Whoops!',
+  };
+}
+
+const requestEvent = {} as RequestEvent;
+
+describe('handleError', () => {
+  beforeEach(() => {
+    mockCaptureException.mockClear();
+    mockAddExceptionMechanism.mockClear();
+    mockScope = new Scope();
+  });
+
+  it('works when a handleError func is not provided', async () => {
+    const wrappedHandleError = handleErrorWithSentry();
+    const mockError = new Error('test');
+    const returnVal = await wrappedHandleError({ error: mockError, event: requestEvent });
+
+    expect(returnVal).not.toBeDefined();
+    expect(mockCaptureException).toHaveBeenCalledTimes(1);
+    expect(mockCaptureException).toHaveBeenCalledWith(mockError, expect.any(Function));
+  });
+
+  it('calls captureException', async () => {
+    const wrappedHandleError = handleErrorWithSentry(handleError);
+    const mockError = new Error('test');
+    const returnVal = await wrappedHandleError({ error: mockError, event: requestEvent });
+
+    expect(returnVal!.message).toEqual('Whoops!');
+    expect(mockCaptureException).toHaveBeenCalledTimes(1);
+    expect(mockCaptureException).toHaveBeenCalledWith(mockError, expect.any(Function));
+  });
+
+  it('adds an exception mechanism', async () => {
+    const addEventProcessorSpy = jest.spyOn(mockScope, 'addEventProcessor').mockImplementationOnce(callback => {
+      void callback({}, { event_id: 'fake-event-id' });
+      return mockScope;
+    });
+
+    const wrappedHandleError = handleErrorWithSentry(handleError);
+    const mockError = new Error('test');
+    await wrappedHandleError({ error: mockError, event: requestEvent });
+
+    expect(addEventProcessorSpy).toBeCalledTimes(1);
+    expect(mockAddExceptionMechanism).toBeCalledTimes(1);
+    expect(mockAddExceptionMechanism).toBeCalledWith({}, { handled: false, type: 'sveltekit' });
+  });
+});