fix: address review

Author: bbrzoska

src/v3/ActiveTrace.ts

@@ -658,24 +658,20 @@ export class ActiveTrace<
         occurrence,
         recordedInState: this.stateMachine
           .currentState as NonTerminalTraceStates,
+        labels: [],
       }
 
-      const labels = this.getSpanLabels({
-        span,
-        annotation,
-      })
-
       spanAndAnnotation = {
         span,
-        annotation: {
-          ...annotation,
-          labels,
-        },
+        annotation,
       }
 
       this.deduplicationStrategy?.recordSpan(span, spanAndAnnotation)
     }
 
+    // make sure the labels are up-to-date
+    spanAndAnnotation.annotation.labels = this.getSpanLabels(spanAndAnnotation)
+
     const transition = this.stateMachine.emit(
       'onProcessSpan',
       spanAndAnnotation,

src/v3/ensureMatcherFn.ts

@@ -1,4 +1,5 @@
 import { type SpanMatch, type SpanMatcherFn, fromDefinition } from './matchSpan'
+import type { LabelMatchingFnsRecord, LabelMatchingInputRecord } from './types'
 import type { ArrayWithAtLeastOneElement, KeysOfUnion } from './typeUtils'
 
 export function ensureMatcherFn<
@@ -48,22 +49,22 @@ export function convertMatchersToFns<
 }
 
 export function convertLabelMatchersToFns<
-  TracerScopeT extends AllPossibleScopesT,
+  TracerScopeKeysT extends KeysOfUnion<AllPossibleScopesT>,
   AllPossibleScopesT,
 >(
-  definitionLabelMatchers: Record<
-    string,
-    SpanMatch<TracerScopeT, AllPossibleScopesT>
+  definitionLabelMatchers: LabelMatchingInputRecord<
+    TracerScopeKeysT,
+    AllPossibleScopesT
   >,
-): Record<string, SpanMatcherFn<TracerScopeT, AllPossibleScopesT>> {
-  return Object.keys(definitionLabelMatchers).reduce<
-    Record<string, SpanMatcherFn<TracerScopeT, AllPossibleScopesT>>
-  >((acc, key) => {
-    if (!definitionLabelMatchers?.[key]) return acc
-    const matchFn = convertMatchersToFns([definitionLabelMatchers[key]])
-    if (matchFn) {
-      acc[key] = matchFn[0]
-    }
-    return acc
-  }, {})
+): LabelMatchingFnsRecord<TracerScopeKeysT, AllPossibleScopesT> {
+  const matchers: LabelMatchingFnsRecord<TracerScopeKeysT, AllPossibleScopesT> =
+    {}
+  for (const key in definitionLabelMatchers) {
+    // eslint-disable-next-line no-continue
+    if (!definitionLabelMatchers?.[key]) continue
+    matchers[key] = ensureMatcherFn<TracerScopeKeysT, AllPossibleScopesT>(
+      definitionLabelMatchers[key],
+    )
+  }
+  return matchers
 }

src/v3/spanAnnotationTypes.ts

@@ -34,9 +34,9 @@ export interface SpanAnnotation {
    */
   markedInteractive?: boolean
   /**
-   * Optional labels for the span based on label definitions from the Tracer.
+   * Labels for the span based on label definitions from the Tracer. Empty if the span didn't match any of the label match definitions.
    */
-  labels?: string[]
+  labels: string[]
 }
 
 export interface SpanAnnotationRecord {

src/v3/types.ts

@@ -120,6 +120,16 @@ export interface CaptureInteractiveConfig extends CPUIdleProcessorOptions {
   timeout?: number
 }
 
+export type LabelMatchingInputRecord<
+  TracerScopeKeysT extends KeysOfUnion<AllPossibleScopesT>,
+  AllPossibleScopesT,
+> = Record<string, SpanMatch<TracerScopeKeysT, AllPossibleScopesT>>
+
+export type LabelMatchingFnsRecord<
+  TracerScopeKeysT extends KeysOfUnion<AllPossibleScopesT>,
+  AllPossibleScopesT,
+> = Record<string, SpanMatcherFn<TracerScopeKeysT, AllPossibleScopesT>>
+
 /**
  * Definition of a trace that includes conditions on when to end, debounce, and interrupt.
  * The "input" version will be transformed into the standardized version internally,
@@ -139,9 +149,9 @@ export interface TraceDefinition<
   scopes: readonly TracerScopeKeysT[]
 
   // TODO: typing this so that the labels are inferred?
-  labelMatching?: Record<
-    string,
-    SpanMatch<NoInfer<TracerScopeT>, AllPossibleScopesT>
+  labelMatching?: LabelMatchingInputRecord<
+    NoInfer<TracerScopeKeysT>,
+    AllPossibleScopesT
   >
 
   /**
@@ -200,9 +210,9 @@ export interface CompleteTraceDefinition<
     SpanMatcherFn<NoInfer<TracerScopeKeysT>, AllPossibleScopesT>[]
   >[]
 
-  labelMatching?: Record<
-    string,
-    SpanMatcherFn<TracerScopeT, AllPossibleScopesT>
+  labelMatching?: LabelMatchingFnsRecord<
+    NoInfer<TracerScopeKeysT>,
+    AllPossibleScopesT
   >
 
   requiredToEnd: ArrayWithAtLeastOneElement<