ref(profiling) use runtime assertion to narrow down on the profile group value

static/app/components/profiling/flamegraph/continuousFlamegraph.tsx

@@ -58,7 +58,7 @@ import {
 import {useDevicePixelRatio} from 'sentry/utils/useDevicePixelRatio';
 import {useMemoWithPrevious} from 'sentry/utils/useMemoWithPrevious';
 import {useContinuousProfile} from 'sentry/views/profiling/continuousProfileProvider';
-import {useProfileGroup} from 'sentry/views/profiling/profileGroupProvider';
+import {useContinuousProfileGroup} from 'sentry/views/profiling/profileGroupProvider';
 
 import {FlamegraphDrawer} from './flamegraphDrawer/flamegraphDrawer';
 import {FlamegraphWarnings} from './flamegraphOverlays/FlamegraphWarnings';
@@ -126,7 +126,7 @@ export function ContinuousFlamegraph(): ReactElement {
   const dispatch = useDispatchFlamegraphState();
 
   const profiles = useContinuousProfile();
-  const profileGroup = useProfileGroup() as ContinuousProfileGroup;
+  const profileGroup = useContinuousProfileGroup();
 
   const flamegraphTheme = useFlamegraphTheme();
   const position = useFlamegraphZoomPosition();

static/app/components/profiling/flamegraph/flamegraph.tsx

@@ -202,7 +202,7 @@ function Flamegraph(): ReactElement {
 
   const profiles = useProfiles();
   const setProfiles = useSetProfiles();
-  const profileGroup = useProfileGroup() as ProfileGroup;
+  const profileGroup = useProfileGroup();
 
   const flamegraphTheme = useFlamegraphTheme();
   const position = useFlamegraphZoomPosition();

static/app/utils/profiling/profile/importProfile.tsx

@@ -42,6 +42,7 @@ export interface ProfileGroup {
   profiles: Profile[];
   traceID: string;
   transactionID: string | null;
+  type: 'transaction';
   images?: Image[];
 }
 
@@ -53,6 +54,7 @@ export interface ContinuousProfileGroup {
   profiles: Profile[];
   traceID: string;
   transactionID: string | null;
+  type: 'continuous';
   images?: Image[];
 }
 
@@ -111,6 +113,7 @@ function importJSSelfProfile(
   const profile = importSingleProfile(input, frameIndex, options);
 
   return {
+    type: 'transaction',
     traceID,
     name: traceID,
     transactionID: null,
@@ -184,6 +187,7 @@ function importSentrySampledProfile(
   }
 
   return {
+    type: 'transaction',
     transactionID: input.transaction.id,
     traceID: input.transaction.trace_id,
     name: input.transaction.name,
@@ -227,6 +231,7 @@ export function importSchema(
   );
 
   return {
+    type: 'transaction',
     traceID,
     transactionID: input.metadata.transactionID ?? null,
     name: input.metadata?.transactionName ?? traceID,
@@ -255,6 +260,7 @@ export function importSentryContinuousProfileChunk(
   return {
     traceID,
     name: '',
+    type: 'continuous',
     transactionID: null,
     activeProfileIndex: 0,
     profiles: [importSingleProfile(input.profile, frameIndex, options)],

static/app/views/profiling/profileGroupProvider.tsx

@@ -9,14 +9,41 @@ import type {
 import {importProfile} from 'sentry/utils/profiling/profile/importProfile';
 
 type ProfileGroupContextValue = ContinuousProfileGroup | ProfileGroup;
-
 const ProfileGroupContext = createContext<ProfileGroupContextValue | null>(null);
 
-export function useProfileGroup() {
+function assertContinuousProfileGroup(
+  input: ProfileGroupContextValue | null
+): asserts input is ContinuousProfileGroup {
+  if (input && input.type !== 'continuous') {
+    throw new Error('ProfileGroup is not of continuous profile type.');
+  }
+}
+
+function assertTransactionProfileGroup(
+  input: ProfileGroupContextValue | null
+): asserts input is ProfileGroup {
+  if (input && input.type !== 'transaction') {
+    throw new Error('ProfileGroup is not of transaction profile type.');
+  }
+}
+
+export function useProfileGroup(): ProfileGroup {
   const context = useContext(ProfileGroupContext);
   if (!context) {
     throw new Error('useProfileGroup was called outside of ProfileGroupProvider');
   }
+  assertTransactionProfileGroup(context);
+  return context;
+}
+
+export function useContinuousProfileGroup(): ContinuousProfileGroup {
+  const context = useContext(ProfileGroupContext);
+  if (!context) {
+    throw new Error(
+      'useContinuousProfileGroup was called outside of ProfileGroupProvider'
+    );
+  }
+  assertContinuousProfileGroup(context);
   return context;
 }
 
@@ -28,6 +55,7 @@ export const LOADING_PROFILE_GROUP: Readonly<ProfileGroup> = {
   measurements: {},
   traceID: '',
   profiles: [],
+  type: 'transaction',
 };
 
 interface ProfileGroupProviderProps {
@@ -52,7 +80,7 @@ export function ProfileGroupProvider(props: ProfileGroupProviderProps) {
   }, [props.input, props.traceID, props.type, props.frameFilter]);
 
   return (
-    <ProfileGroupContext.Provider value={profileGroup as ContinuousProfileGroup}>
+    <ProfileGroupContext.Provider value={profileGroup}>
       {props.children}
     </ProfileGroupContext.Provider>
   );