feat(tracing): Add PropagationContext to scope (#8421)

ref #8352

For more details about PropagationContext, see
https://www.notion.so/sentry/Tracing-without-performance-efab307eb7f64e71a04f09dc72722530

Building off of work in both
#8403 and
#8418, this PR adds
`PropagationContext` and uses that to always set a trace context on
outgoing error events.

Currently if there is an active span on the scope, we automatically
attach that span's trace context to all outgoing events. Now, we want to
rely on either the active span or fallback to the propagation context to
ensure that there is always a trace being generated and propagated.

Next up we'll work on updating the node/browser SDKs to update the
propagation context. For example, we should update the propagation
context for node based on the incoming sentry-trace/baggage headers.

Author: AbhiPrasad

packages/browser-integration-tests/suites/replay/captureReplay/test.ts

@@ -56,7 +56,6 @@ sentryTest('should capture replays (@sentry/browser export)', async ({ getLocalT
       version: SDK_VERSION,
       name: 'sentry.javascript.browser',
     },
-    sdkProcessingMetadata: {},
     request: {
       url: expect.stringContaining('/dist/index.html'),
       headers: {
@@ -94,7 +93,6 @@ sentryTest('should capture replays (@sentry/browser export)', async ({ getLocalT
       version: SDK_VERSION,
       name: 'sentry.javascript.browser',
     },
-    sdkProcessingMetadata: {},
     request: {
       url: expect.stringContaining('/dist/index.html'),
       headers: {

packages/browser-integration-tests/suites/replay/captureReplayFromReplayPackage/test.ts

@@ -56,7 +56,6 @@ sentryTest('should capture replays (@sentry/replay export)', async ({ getLocalTe
       version: SDK_VERSION,
       name: 'sentry.javascript.browser',
     },
-    sdkProcessingMetadata: {},
     request: {
       url: expect.stringContaining('/dist/index.html'),
       headers: {
@@ -94,7 +93,6 @@ sentryTest('should capture replays (@sentry/replay export)', async ({ getLocalTe
       version: SDK_VERSION,
       name: 'sentry.javascript.browser',
     },
-    sdkProcessingMetadata: {},
     request: {
       url: expect.stringContaining('/dist/index.html'),
       headers: {

packages/browser-integration-tests/utils/replayEventTemplates.ts

@@ -30,7 +30,6 @@ const DEFAULT_REPLAY_EVENT = {
     version: SDK_VERSION,
     name: 'sentry.javascript.browser',
   },
-  sdkProcessingMetadata: {},
   request: {
     url: expect.stringContaining('/dist/index.html'),
     headers: {

packages/core/src/baseclient.ts

@@ -15,6 +15,7 @@ import type {
   Integration,
   IntegrationClass,
   Outcome,
+  PropagationContext,
   SdkMetadata,
   Session,
   SessionAggregates,
@@ -29,6 +30,7 @@ import {
   addItemToEnvelope,
   checkOrSetAlreadyCaught,
   createAttachmentEnvelopeItem,
+  dropUndefinedKeys,
   isPlainObject,
   isPrimitive,
   isThenable,
@@ -41,6 +43,7 @@ import {
 } from '@sentry/utils';
 
 import { getEnvelopeEndpointWithUrlEncodedAuth } from './api';
+import { DEFAULT_ENVIRONMENT } from './constants';
 import { createEventEnvelope, createSessionEnvelope } from './envelope';
 import type { IntegrationIndex } from './integration';
 import { setupIntegration, setupIntegrations } from './integration';
@@ -507,7 +510,49 @@ export abstract class BaseClient<O extends ClientOptions> implements Client<O> {
     if (!hint.integrations && integrations.length > 0) {
       hint.integrations = integrations;
     }
-    return prepareEvent(options, event, hint, scope);
+    return prepareEvent(options, event, hint, scope).then(evt => {
+      if (evt === null) {
+        return evt;
+      }
+
+      // If a trace context is not set on the event, we use the propagationContext set on the event to
+      // generate a trace context. If the propagationContext does not have a dynamic sampling context, we
+      // also generate one for it.
+      const { propagationContext } = evt.sdkProcessingMetadata || {};
+      const trace = evt.contexts && evt.contexts.trace;
+      if (!trace && propagationContext) {
+        const { traceId: trace_id, spanId, parentSpanId, dsc } = propagationContext as PropagationContext;
+        evt.contexts = {
+          trace: {
+            trace_id,
+            span_id: spanId,
+            parent_span_id: parentSpanId,
+          },
+          ...evt.contexts,
+        };
+
+        const { publicKey: public_key } = this.getDsn() || {};
+        const { segment: user_segment } = (scope && scope.getUser()) || {};
+
+        let dynamicSamplingContext = dsc;
+        if (!dsc) {
+          dynamicSamplingContext = dropUndefinedKeys({
+            environment: options.environment || DEFAULT_ENVIRONMENT,
+            release: options.release,
+            user_segment,
+            public_key,
+            trace_id,
+          });
+          this.emit && this.emit('createDsc', dynamicSamplingContext);
+        }
+
+        evt.sdkProcessingMetadata = {
+          dynamicSamplingContext,
+          ...evt.sdkProcessingMetadata,
+        };
+      }
+      return evt;
+    });
   }
 
   /**

packages/core/src/scope.ts

@@ -11,6 +11,7 @@ import type {
   Extra,
   Extras,
   Primitive,
+  PropagationContext,
   RequestSession,
   Scope as ScopeInterface,
   ScopeContext,
@@ -29,6 +30,7 @@ import {
   isThenable,
   logger,
   SyncPromise,
+  uuid4,
 } from '@sentry/utils';
 
 import { updateSession } from './session';
@@ -70,6 +72,9 @@ export class Scope implements ScopeInterface {
   /** Attachments */
   protected _attachments: Attachment[];
 
+  /** Propagation Context for distributed tracing */
+  protected _propagationContext: PropagationContext;
+
   /**
    * A place to stash data which is needed at some point in the SDK's event processing pipeline but which shouldn't get
    * sent to Sentry
@@ -108,6 +113,7 @@ export class Scope implements ScopeInterface {
     this._extra = {};
     this._contexts = {};
     this._sdkProcessingMetadata = {};
+    this._propagationContext = generatePropagationContext();
   }
 
   /**
@@ -131,6 +137,7 @@ export class Scope implements ScopeInterface {
       newScope._requestSession = scope._requestSession;
       newScope._attachments = [...scope._attachments];
       newScope._sdkProcessingMetadata = { ...scope._sdkProcessingMetadata };
+      newScope._propagationContext = { ...scope._propagationContext };
     }
     return newScope;
   }
@@ -347,6 +354,9 @@ export class Scope implements ScopeInterface {
       if (captureContext._requestSession) {
         this._requestSession = captureContext._requestSession;
       }
+      if (captureContext._propagationContext) {
+        this._propagationContext = captureContext._propagationContext;
+      }
     } else if (isPlainObject(captureContext)) {
       // eslint-disable-next-line no-param-reassign
       captureContext = captureContext as ScopeContext;
@@ -365,6 +375,9 @@ export class Scope implements ScopeInterface {
       if (captureContext.requestSession) {
         this._requestSession = captureContext.requestSession;
       }
+      if (captureContext.propagationContext) {
+        this._propagationContext = captureContext.propagationContext;
+      }
     }
 
     return this;
@@ -387,6 +400,7 @@ export class Scope implements ScopeInterface {
     this._session = undefined;
     this._notifyScopeListeners();
     this._attachments = [];
+    this._propagationContext = generatePropagationContext();
     return this;
   }
 
@@ -500,7 +514,11 @@ export class Scope implements ScopeInterface {
     event.breadcrumbs = [...(event.breadcrumbs || []), ...this._breadcrumbs];
     event.breadcrumbs = event.breadcrumbs.length > 0 ? event.breadcrumbs : undefined;
 
-    event.sdkProcessingMetadata = { ...event.sdkProcessingMetadata, ...this._sdkProcessingMetadata };
+    event.sdkProcessingMetadata = {
+      ...event.sdkProcessingMetadata,
+      ...this._sdkProcessingMetadata,
+      propagationContext: this._propagationContext,
+    };
 
     return this._notifyEventProcessors([...getGlobalEventProcessors(), ...this._eventProcessors], event, hint);
   }
@@ -514,6 +532,14 @@ export class Scope implements ScopeInterface {
     return this;
   }
 
+  /**
+   * @inheritdoc
+   */
+  public setPropagationContext(context: PropagationContext): this {
+    this._propagationContext = context;
+    return this;
+  }
+
   /**
    * This will be called after {@link applyToEvent} is finished.
    */
@@ -598,3 +624,11 @@ function getGlobalEventProcessors(): EventProcessor[] {
 export function addGlobalEventProcessor(callback: EventProcessor): void {
   getGlobalEventProcessors().push(callback);
 }
+
+function generatePropagationContext(): PropagationContext {
+  return {
+    traceId: uuid4(),
+    spanId: uuid4().substring(16),
+    sampled: false,
+  };
+}

packages/core/test/lib/base.test.ts

@@ -492,6 +492,28 @@ describe('BaseClient', () => {
       );
     });
 
+    test('it adds a trace context all events', () => {
+      expect.assertions(1);
+
+      const options = getDefaultTestClientOptions({ dsn: PUBLIC_DSN });
+      const client = new TestClient(options);
+      const scope = new Scope();
+
+      client.captureEvent({ message: 'message' }, { event_id: 'wat' }, scope);
+
+      expect(TestClient.instance!.event!).toEqual(
+        expect.objectContaining({
+          contexts: {
+            trace: {
+              parent_span_id: undefined,
+              span_id: expect.any(String),
+              trace_id: expect.any(String),
+            },
+          },
+        }),
+      );
+    });
+
     test('adds `event_id` from hint if available', () => {
       expect.assertions(1);
 

packages/hub/test/scope.test.ts

@@ -12,6 +12,21 @@ describe('Scope', () => {
     GLOBAL_OBJ.__SENTRY__.globalEventProcessors = undefined;
   });
 
+  describe('init', () => {
+    test('it creates a propagation context', () => {
+      const scope = new Scope();
+
+      // @ts-ignore asserting on private properties
+      expect(scope._propagationContext).toEqual({
+        traceId: expect.any(String),
+        spanId: expect.any(String),
+        sampled: false,
+        dsc: undefined,
+        parentSpanId: undefined,
+      });
+    });
+  });
+
   describe('attributes modification', () => {
     test('setFingerprint', () => {
       const scope = new Scope();
@@ -193,6 +208,14 @@ describe('Scope', () => {
       expect(parentScope.getRequestSession()).toEqual({ status: 'ok' });
       expect(scope.getRequestSession()).toEqual({ status: 'ok' });
     });
+
+    test('should clone propagation context', () => {
+      const parentScope = new Scope();
+      const scope = Scope.clone(parentScope);
+
+      // @ts-ignore accessing private property for test
+      expect(scope._propagationContext).toEqual(parentScope._propagationContext);
+    });
   });
 
   describe('applyToEvent', () => {
@@ -220,7 +243,11 @@ describe('Scope', () => {
         expect(processedEvent!.transaction).toEqual('/abc');
         expect(processedEvent!.breadcrumbs![0]).toHaveProperty('message', 'test');
         expect(processedEvent!.contexts).toEqual({ os: { id: '1' } });
-        expect(processedEvent!.sdkProcessingMetadata).toEqual({ dogs: 'are great!' });
+        expect(processedEvent!.sdkProcessingMetadata).toEqual({
+          dogs: 'are great!',
+          // @ts-expect-error accessing private property for test
+          propagationContext: scope._propagationContext,
+        });
       });
     });
 
@@ -339,7 +366,7 @@ describe('Scope', () => {
       scope.setSpan(span);
       const event: Event = {
         contexts: {
-          trace: { a: 'c' },
+          trace: { a: 'c' } as any,
         },
       };
       return scope.applyToEvent(event).then(processedEvent => {
@@ -383,6 +410,8 @@ describe('Scope', () => {
 
   test('clear', () => {
     const scope = new Scope();
+    // @ts-expect-error accessing private property
+    const oldPropagationContext = scope._propagationContext;
     scope.setExtra('a', 2);
     scope.setTag('a', 'b');
     scope.setUser({ id: '1' });
@@ -393,6 +422,14 @@ describe('Scope', () => {
     scope.clear();
     expect((scope as any)._extra).toEqual({});
     expect((scope as any)._requestSession).toEqual(undefined);
+    // @ts-expect-error accessing private property
+    expect(scope._propagationContext).toEqual({
+      traceId: expect.any(String),
+      spanId: expect.any(String),
+      sampled: false,
+    });
+    // @ts-expect-error accessing private property
+    expect(scope._propagationContext).not.toEqual(oldPropagationContext);
   });
 
   test('clearBreadcrumbs', () => {
@@ -486,6 +523,8 @@ describe('Scope', () => {
       expect(updatedScope._level).toEqual('warning');
       expect(updatedScope._fingerprint).toEqual(['bar']);
       expect(updatedScope._requestSession.status).toEqual('ok');
+      // @ts-ignore accessing private property for test
+      expect(updatedScope._propagationContext).toEqual(localScope._propagationContext);
     });
 
     test('given an empty instance of Scope, it should preserve all the original scope data', () => {
@@ -518,7 +557,13 @@ describe('Scope', () => {
         tags: { bar: '3', baz: '4' },
         user: { id: '42' },
         requestSession: { status: 'errored' as RequestSessionStatus },
+        propagationContext: {
+          traceId: '8949daf83f4a4a70bee4c1eb9ab242ed',
+          spanId: 'a024ad8fea82680e',
+          sampled: true,
+        },
       };
+
       const updatedScope = scope.update(localAttributes) as any;
 
       expect(updatedScope._tags).toEqual({
@@ -540,6 +585,11 @@ describe('Scope', () => {
       expect(updatedScope._level).toEqual('warning');
       expect(updatedScope._fingerprint).toEqual(['bar']);
       expect(updatedScope._requestSession).toEqual({ status: 'errored' });
+      expect(updatedScope._propagationContext).toEqual({
+        traceId: '8949daf83f4a4a70bee4c1eb9ab242ed',
+        spanId: 'a024ad8fea82680e',
+        sampled: true,
+      });
     });
   });
 

packages/node/test/async/domain.test.ts

@@ -1,5 +1,5 @@
-import { getCurrentHub, Hub, runWithAsyncContext, setAsyncContextStrategy } from '@sentry/core';
-import * as domain from 'domain';
+import type { Hub } from '@sentry/core';
+import { getCurrentHub, runWithAsyncContext, setAsyncContextStrategy } from '@sentry/core';
 
 import { setDomainAsyncContextStrategy } from '../../src/async/domain';
 
@@ -9,13 +9,6 @@ describe('domains', () => {
     setAsyncContextStrategy(undefined);
   });
 
-  test('without domain', () => {
-    // @ts-ignore property active does not exist on domain
-    expect(domain.active).toBeFalsy();
-    const hub = getCurrentHub();
-    expect(hub).toEqual(new Hub());
-  });
-
   test('hub scope inheritance', () => {
     setDomainAsyncContextStrategy();