feat(sveltekit): Add performance monitoring to Sveltekit server handle (#7532)

AbhiPrasad · web-flow · commit 15a36bcd643d · 2023-03-21T13:17:24.000+01:00
diff --git a/packages/sveltekit/src/server/handle.ts b/packages/sveltekit/src/server/handle.ts
@@ -0,0 +1,103 @@
+/* eslint-disable @sentry-internal/sdk/no-optional-chaining */
+import { captureException, getCurrentHub, startTransaction } from '@sentry/node';
+import type { Transaction } from '@sentry/types';
+import {
+  addExceptionMechanism,
+  baggageHeaderToDynamicSamplingContext,
+  extractTraceparentData,
+  isThenable,
+  objectify,
+} from '@sentry/utils';
+import type { Handle } from '@sveltejs/kit';
+import * as domain from 'domain';
+
+function sendErrorToSentry(e: unknown): unknown {
+  // In case we have a primitive, wrap it in the equivalent wrapper class (string -> String, etc.) so that we can
+  // store a seen flag on it.
+  const objectifiedErr = objectify(e);
+
+  captureException(objectifiedErr, scope => {
+    scope.addEventProcessor(event => {
+      addExceptionMechanism(event, {
+        type: 'sveltekit',
+        handled: false,
+        data: {
+          function: 'handle',
+        },
+      });
+      return event;
+    });
+
+    return scope;
+  });
+
+  return objectifiedErr;
+}
+
+/**
+ * A SvelteKit handle function that wraps the request for Sentry error and
+ * performance monitoring.
+ *
+ * Usage:
+ * ```
+ * // src/hooks.server.ts
+ * import { sentryHandle } from '@sentry/sveltekit';
+ *
+ * export const handle = sentryHandle;
+ *
+ * // Optionally use the sequence function to add additional handlers.
+ * // export const handle = sequence(sentryHandle, yourCustomHandle);
+ * ```
+ */
+export const sentryHandle: Handle = ({ event, resolve }) => {
+  return domain.create().bind(() => {
+    let maybePromiseResult;
+
+    const sentryTraceHeader = event.request.headers.get('sentry-trace');
+    const baggageHeader = event.request.headers.get('baggage');
+    const traceparentData = sentryTraceHeader ? extractTraceparentData(sentryTraceHeader) : undefined;
+    const dynamicSamplingContext = baggageHeaderToDynamicSamplingContext(baggageHeader);
+
+    // transaction could be undefined if hub extensions were not added.
+    const transaction: Transaction | undefined = startTransaction({
+      op: 'http.server',
+      name: `${event.request.method} ${event.route.id}`,
+      status: 'ok',
+      ...traceparentData,
+      metadata: {
+        source: 'route',
+        dynamicSamplingContext: traceparentData && !dynamicSamplingContext ? {} : dynamicSamplingContext,
+      },
+    });
+
+    getCurrentHub().getScope()?.setSpan(transaction);
+
+    try {
+      maybePromiseResult = resolve(event);
+    } catch (e) {
+      transaction?.setStatus('internal_error');
+      const sentryError = sendErrorToSentry(e);
+      transaction?.finish();
+      throw sentryError;
+    }
+
+    if (isThenable(maybePromiseResult)) {
+      Promise.resolve(maybePromiseResult).then(
+        response => {
+          transaction?.setHttpStatus(response.status);
+          transaction?.finish();
+        },
+        e => {
+          transaction?.setStatus('internal_error');
+          sendErrorToSentry(e);
+          transaction?.finish();
+        },
+      );
+    } else {
+      transaction?.setHttpStatus(maybePromiseResult.status);
+      transaction?.finish();
+    }
+
+    return maybePromiseResult;
+  })();
+};
diff --git a/packages/sveltekit/src/server/index.ts b/packages/sveltekit/src/server/index.ts
@@ -3,3 +3,4 @@ export * from '@sentry/node';
 export { init } from './sdk';
 export { handleErrorWithSentry } from './handleError';
 export { wrapLoadWithSentry } from './load';
+export { sentryHandle } from './handle';
diff --git a/packages/sveltekit/test/server/handle.test.ts b/packages/sveltekit/test/server/handle.test.ts
@@ -0,0 +1,251 @@
+import { addTracingExtensions, Hub, makeMain, Scope } from '@sentry/core';
+import { NodeClient } from '@sentry/node';
+import type { Transaction } from '@sentry/types';
+import type { Handle } from '@sveltejs/kit';
+import { vi } from 'vitest';
+
+import { sentryHandle } from '../../src/server/handle';
+import { getDefaultNodeClientOptions } from '../utils';
+
+const mockCaptureException = vi.fn();
+let mockScope = new Scope();
+
+vi.mock('@sentry/node', async () => {
+  const original = (await vi.importActual('@sentry/node')) as any;
+  return {
+    ...original,
+    captureException: (err: unknown, cb: (arg0: unknown) => unknown) => {
+      cb(mockScope);
+      mockCaptureException(err, cb);
+      return original.captureException(err, cb);
+    },
+  };
+});
+
+const mockAddExceptionMechanism = vi.fn();
+
+vi.mock('@sentry/utils', async () => {
+  const original = (await vi.importActual('@sentry/utils')) as any;
+  return {
+    ...original,
+    addExceptionMechanism: (...args: unknown[]) => mockAddExceptionMechanism(...args),
+  };
+});
+
+function mockEvent(override: Record<string, unknown> = {}): Parameters<Handle>[0]['event'] {
+  const event: Parameters<Handle>[0]['event'] = {
+    cookies: {} as any,
+    fetch: () => Promise.resolve({} as any),
+    getClientAddress: () => '',
+    locals: {},
+    params: { id: '123' },
+    platform: {},
+    request: {
+      method: 'GET',
+      headers: {
+        get: () => null,
+        append: () => {},
+        delete: () => {},
+        forEach: () => {},
+        has: () => false,
+        set: () => {},
+      },
+    } as any,
+    route: { id: '/users/[id]' },
+    setHeaders: () => {},
+    url: new URL('http://localhost:3000/users/123'),
+    isDataRequest: false,
+
+    ...override,
+  };
+
+  return event;
+}
+
+const mockResponse = { status: 200, headers: {}, body: '' } as any;
+
+const enum Type {
+  Sync = 'sync',
+  Async = 'async',
+}
+
+function resolve(type: Type, isError: boolean): Parameters<Handle>[0]['resolve'] {
+  if (type === Type.Sync) {
+    return (..._args: unknown[]) => {
+      if (isError) {
+        throw new Error(type);
+      }
+
+      return mockResponse;
+    };
+  }
+
+  return (..._args: unknown[]) => {
+    return new Promise((resolve, reject) => {
+      if (isError) {
+        reject(new Error(type));
+      } else {
+        resolve(mockResponse);
+      }
+    });
+  };
+}
+
+let hub: Hub;
+let client: NodeClient;
+
+describe('handleSentry', () => {
+  beforeAll(() => {
+    addTracingExtensions();
+  });
+
+  beforeEach(() => {
+    mockScope = new Scope();
+    const options = getDefaultNodeClientOptions({ tracesSampleRate: 1.0 });
+    client = new NodeClient(options);
+    hub = new Hub(client);
+    makeMain(hub);
+
+    mockCaptureException.mockClear();
+    mockAddExceptionMechanism.mockClear();
+  });
+
+  describe.each([
+    // isSync, isError, expectedResponse
+    [Type.Sync, true, undefined],
+    [Type.Sync, false, mockResponse],
+    [Type.Async, true, undefined],
+    [Type.Async, false, mockResponse],
+  ])('%s resolve with error %s', (type, isError, mockResponse) => {
+    it('should return a response', async () => {
+      let response: any = undefined;
+      try {
+        response = await sentryHandle({ event: mockEvent(), resolve: resolve(type, isError) });
+      } catch (e) {
+        expect(e).toBeInstanceOf(Error);
+        expect(e.message).toEqual(type);
+      }
+
+      expect(response).toEqual(mockResponse);
+    });
+
+    it('creates a transaction', async () => {
+      let ref: any = undefined;
+      client.on('finishTransaction', (transaction: Transaction) => {
+        ref = transaction;
+      });
+
+      try {
+        await sentryHandle({ event: mockEvent(), resolve: resolve(type, isError) });
+      } catch (e) {
+        //
+      }
+
+      expect(ref).toBeDefined();
+
+      expect(ref.name).toEqual('GET /users/[id]');
+      expect(ref.op).toEqual('http.server');
+      expect(ref.status).toEqual(isError ? 'internal_error' : 'ok');
+      expect(ref.metadata.source).toEqual('route');
+
+      expect(ref.endTimestamp).toBeDefined();
+    });
+
+    it('creates a transaction from sentry-trace header', async () => {
+      const event = mockEvent({
+        request: {
+          headers: {
+            get: (key: string) => {
+              if (key === 'sentry-trace') {
+                return '1234567890abcdef1234567890abcdef-1234567890abcdef-1';
+              }
+
+              return null;
+            },
+          },
+        },
+      });
+
+      let ref: any = undefined;
+      client.on('finishTransaction', (transaction: Transaction) => {
+        ref = transaction;
+      });
+
+      try {
+        await sentryHandle({ event, resolve: resolve(type, isError) });
+      } catch (e) {
+        //
+      }
+
+      expect(ref).toBeDefined();
+      expect(ref.traceId).toEqual('1234567890abcdef1234567890abcdef');
+      expect(ref.parentSpanId).toEqual('1234567890abcdef');
+      expect(ref.sampled).toEqual(true);
+    });
+
+    it('creates a transaction with dynamic sampling context from baggage header', async () => {
+      const event = mockEvent({
+        request: {
+          headers: {
+            get: (key: string) => {
+              if (key === 'sentry-trace') {
+                return '1234567890abcdef1234567890abcdef-1234567890abcdef-1';
+              }
+
+              if (key === 'baggage') {
+                return (
+                  'sentry-environment=production,sentry-release=1.0.0,sentry-transaction=dogpark,' +
+                  'sentry-user_segment=segmentA,sentry-public_key=dogsarebadatkeepingsecrets,' +
+                  'sentry-trace_id=1234567890abcdef1234567890abcdef,sentry-sample_rate=1'
+                );
+              }
+
+              return null;
+            },
+          },
+        },
+      });
+
+      let ref: any = undefined;
+      client.on('finishTransaction', (transaction: Transaction) => {
+        ref = transaction;
+      });
+
+      try {
+        await sentryHandle({ event, resolve: resolve(type, isError) });
+      } catch (e) {
+        //
+      }
+
+      expect(ref).toBeDefined();
+      expect(ref.metadata.dynamicSamplingContext).toEqual({
+        environment: 'production',
+        release: '1.0.0',
+        public_key: 'dogsarebadatkeepingsecrets',
+        sample_rate: '1',
+        trace_id: '1234567890abcdef1234567890abcdef',
+        transaction: 'dogpark',
+        user_segment: 'segmentA',
+      });
+    });
+
+    it('send errors to Sentry', async () => {
+      const addEventProcessorSpy = vi.spyOn(mockScope, 'addEventProcessor').mockImplementationOnce(callback => {
+        void callback({}, { event_id: 'fake-event-id' });
+        return mockScope;
+      });
+
+      try {
+        await sentryHandle({ event: mockEvent(), resolve: resolve(type, isError) });
+      } catch (e) {
+        expect(mockCaptureException).toBeCalledTimes(1);
+        expect(addEventProcessorSpy).toBeCalledTimes(1);
+        expect(mockAddExceptionMechanism).toBeCalledTimes(1);
+        expect(mockAddExceptionMechanism).toBeCalledWith(
+          {},
+          { handled: false, type: 'sveltekit', data: { function: 'handle' } },
+        );
+      }
+    });
+  });
+});
diff --git a/packages/sveltekit/test/utils.ts b/packages/sveltekit/test/utils.ts
@@ -0,0 +1,12 @@
+import { createTransport } from '@sentry/core';
+import type { ClientOptions } from '@sentry/types';
+import { resolvedSyncPromise } from '@sentry/utils';
+
+export function getDefaultNodeClientOptions(options: Partial<ClientOptions> = {}): ClientOptions {
+  return {
+    integrations: [],
+    transport: () => createTransport({ recordDroppedEvent: () => undefined }, _ => resolvedSyncPromise({})),
+    stackParser: () => [],
+    ...options,
+  };
+}
