From 90714e146fe00976ae16d271a0739326d0e04351 Mon Sep 17 00:00:00 2001
From: Andrew Liu <159852527+aliu39@users.noreply.github.com>
Date: Sun, 29 Dec 2024 20:53:11 -0800
Subject: [PATCH 01/19] Init[WIP]

---
 packages/browser/src/index.ts                 |  1 +
 .../featureFlags/unleash/index.ts             |  1 +
 .../featureFlags/unleash/integration.ts       | 36 +++++++++++++++++++
 .../featureFlags/unleash/types.ts             | 11 ++++++
 4 files changed, 49 insertions(+)
 create mode 100644 packages/browser/src/integrations/featureFlags/unleash/index.ts
 create mode 100644 packages/browser/src/integrations/featureFlags/unleash/integration.ts
 create mode 100644 packages/browser/src/integrations/featureFlags/unleash/types.ts

diff --git a/packages/browser/src/index.ts b/packages/browser/src/index.ts
index e6f57c13fe6b..e6e089cbe04c 100644
--- a/packages/browser/src/index.ts
+++ b/packages/browser/src/index.ts
@@ -75,3 +75,4 @@ export {
 } from './integrations/featureFlags';
 export { launchDarklyIntegration, buildLaunchDarklyFlagUsedHandler } from './integrations/featureFlags/launchdarkly';
 export { openFeatureIntegration, OpenFeatureIntegrationHook } from './integrations/featureFlags/openfeature';
+export { unleashIntegration } from './integrations/featureFlags/unleash';
diff --git a/packages/browser/src/integrations/featureFlags/unleash/index.ts b/packages/browser/src/integrations/featureFlags/unleash/index.ts
new file mode 100644
index 000000000000..934ff196ee95
--- /dev/null
+++ b/packages/browser/src/integrations/featureFlags/unleash/index.ts
@@ -0,0 +1 @@
+export { unleashIntegration } from './integration';
diff --git a/packages/browser/src/integrations/featureFlags/unleash/integration.ts b/packages/browser/src/integrations/featureFlags/unleash/integration.ts
new file mode 100644
index 000000000000..c4e3bec09f20
--- /dev/null
+++ b/packages/browser/src/integrations/featureFlags/unleash/integration.ts
@@ -0,0 +1,36 @@
+import type { Client, Event, EventHint, IntegrationFn } from '@sentry/core';
+
+import { defineIntegration } from '@sentry/core';
+import { copyFlagsFromScopeToEvent, insertFlagToScope } from '../../../utils/featureFlags';
+import type { UnleashClient } from './types';
+
+/**
+ * Sentry integration for capturing feature flags from the Unleash SDK.
+ *
+ * See the [feature flag documentation](https://develop.sentry.dev/sdk/expected-features/#feature-flags) for more information.
+ *
+ * @example
+ * ```
+ * import * as Sentry from '@sentry/browser';
+ * TODO:
+ *
+ * Sentry.init({
+ *   dsn: '___PUBLIC_DSN___',
+ *   integrations: [TODO:]
+ * });
+ * ```
+ */
+export const unleashIntegration = defineIntegration((openFeatureClient: UnleashClient ) => {
+  return {
+    name: 'Unleash',
+
+    processEvent(event: Event, _hint: EventHint, _client: Client): Event {
+      return copyFlagsFromScopeToEvent(event);
+    },
+
+    setupOnce() {
+      openFeatureClient.isEnabled = Proxy();
+      openFeatureClient.getVariant = Proxy();
+    },
+  };
+}) satisfies IntegrationFn;
diff --git a/packages/browser/src/integrations/featureFlags/unleash/types.ts b/packages/browser/src/integrations/featureFlags/unleash/types.ts
new file mode 100644
index 000000000000..520bfcbdc182
--- /dev/null
+++ b/packages/browser/src/integrations/featureFlags/unleash/types.ts
@@ -0,0 +1,11 @@
+export type Variant = {
+  variantName: string;
+  enabled: boolean;
+  payload?: object; // TODO:
+  // TODO:
+}
+
+export interface UnleashClient {
+  isEnabled(featureName: string): boolean;
+  getVariant(featureName: string): Variant;
+}

From e714b9eeaeeca523710dea3a2f30b9ab33aa3bca Mon Sep 17 00:00:00 2001
From: Andrew Liu <159852527+aliu39@users.noreply.github.com>
Date: Wed, 8 Jan 2025 16:19:53 -0800
Subject: [PATCH 02/19] Working patch and basic test for isEnabled

---
 .../featureFlags/unleash/basic/test.ts        | 47 +++++++++++++++++++
 .../integrations/featureFlags/unleash/init.js | 25 ++++++++++
 .../featureFlags/unleash/subject.js           |  3 ++
 .../featureFlags/unleash/template.html        |  9 ++++
 .../featureFlags/unleash/integration.ts       | 24 ++++++++--
 .../featureFlags/unleash/types.ts             | 17 ++++---
 6 files changed, 115 insertions(+), 10 deletions(-)
 create mode 100644 dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/basic/test.ts
 create mode 100644 dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/init.js
 create mode 100644 dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/subject.js
 create mode 100644 dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/template.html

diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/basic/test.ts b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/basic/test.ts
new file mode 100644
index 000000000000..79361c137128
--- /dev/null
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/basic/test.ts
@@ -0,0 +1,47 @@
+import { expect } from '@playwright/test';
+
+import { sentryTest } from '../../../../../utils/fixtures';
+
+import { envelopeRequestParser, shouldSkipFeatureFlagsTest, waitForErrorRequest } from '../../../../../utils/helpers';
+
+const FLAG_BUFFER_SIZE = 100; // Corresponds to constant in featureFlags.ts, in browser utils.
+
+sentryTest('Basic test with eviction, update, and no async tasks', async ({ getLocalTestUrl, page }) => {
+  if (shouldSkipFeatureFlagsTest()) {
+    sentryTest.skip();
+  }
+
+  await page.route('https://dsn.ingest.sentry.io/**/*', route => {
+    return route.fulfill({
+      status: 200,
+      contentType: 'application/json',
+      body: JSON.stringify({ id: 'test-id' }),
+    });
+  });
+
+  const url = await getLocalTestUrl({ testDir: __dirname, skipDsnRouteHandler: true });
+  await page.goto(url);
+
+  await page.evaluate(bufferSize => {
+    const client = new (window as any).UnleashClient();
+    for (let i = 1; i <= bufferSize; i++) {
+      client.isEnabled(`feat${i}`);
+    }
+    client.isEnabled(`feat${bufferSize + 1}`); // eviction
+    client.isEnabled('feat3'); // update
+  }, FLAG_BUFFER_SIZE);
+
+  const reqPromise = waitForErrorRequest(page);
+  await page.locator('#error').click();
+  const req = await reqPromise;
+  const event = envelopeRequestParser(req);
+
+  const expectedFlags = [{ flag: 'feat2', result: false }];
+  for (let i = 4; i <= FLAG_BUFFER_SIZE; i++) {
+    expectedFlags.push({ flag: `feat${i}`, result: false });
+  }
+  expectedFlags.push({ flag: `feat${FLAG_BUFFER_SIZE + 1}`, result: false });
+  expectedFlags.push({ flag: 'feat3', result: false });
+
+  expect(event.contexts?.flags?.values).toEqual(expectedFlags);
+});
diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/init.js b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/init.js
new file mode 100644
index 000000000000..f40861483bea
--- /dev/null
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/init.js
@@ -0,0 +1,25 @@
+import * as Sentry from '@sentry/browser';
+
+window.UnleashClient = class {
+  isEnabled(_toggleName) {
+    return false;
+  }
+
+  getVariant(_toggleName) {
+    return {
+      name: 'disabled',
+      enabled: false,
+    };
+  }
+};
+
+window.Sentry = Sentry;
+window.sentryUnleashIntegration = Sentry.unleashIntegration(window.UnleashClient);
+
+Sentry.init({
+  dsn: 'https://public@dsn.ingest.sentry.io/1337',
+  sampleRate: 1.0,
+  integrations: [window.sentryUnleashIntegration],
+});
+
+
diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/subject.js b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/subject.js
new file mode 100644
index 000000000000..e6697408128c
--- /dev/null
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/subject.js
@@ -0,0 +1,3 @@
+document.getElementById('error').addEventListener('click', () => {
+  throw new Error('Button triggered error');
+});
diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/template.html b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/template.html
new file mode 100644
index 000000000000..9330c6c679f4
--- /dev/null
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/template.html
@@ -0,0 +1,9 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <meta charset="utf-8" />
+  </head>
+  <body>
+    <button id="error">Throw Error</button>
+  </body>
+</html>
diff --git a/packages/browser/src/integrations/featureFlags/unleash/integration.ts b/packages/browser/src/integrations/featureFlags/unleash/integration.ts
index c4e3bec09f20..470f70cb9924 100644
--- a/packages/browser/src/integrations/featureFlags/unleash/integration.ts
+++ b/packages/browser/src/integrations/featureFlags/unleash/integration.ts
@@ -2,7 +2,7 @@ import type { Client, Event, EventHint, IntegrationFn } from '@sentry/core';
 
 import { defineIntegration } from '@sentry/core';
 import { copyFlagsFromScopeToEvent, insertFlagToScope } from '../../../utils/featureFlags';
-import type { UnleashClient } from './types';
+import type { UnleashClient, UnleashClientClass } from './types';
 
 /**
  * Sentry integration for capturing feature flags from the Unleash SDK.
@@ -20,7 +20,7 @@ import type { UnleashClient } from './types';
  * });
  * ```
  */
-export const unleashIntegration = defineIntegration((openFeatureClient: UnleashClient ) => {
+export const unleashIntegration = defineIntegration((unleashClientClass: UnleashClientClass) => {
   return {
     name: 'Unleash',
 
@@ -29,8 +29,24 @@ export const unleashIntegration = defineIntegration((openFeatureClient: UnleashC
     },
 
     setupOnce() {
-      openFeatureClient.isEnabled = Proxy();
-      openFeatureClient.getVariant = Proxy();
+      const sentryIsEnabled = {
+        apply: (
+          target: (this: UnleashClient, toggleName: string) => boolean,
+          thisArg: UnleashClient,
+          args: [toggleName: string]
+        ) => {
+          const result = Reflect.apply(target, thisArg, args);
+          insertFlagToScope(args[0], result);
+          return result;
+        }
+      };
+      const unleashClientPrototype = unleashClientClass.prototype as UnleashClient;
+      const originalIsEnabled = unleashClientPrototype.isEnabled.bind(unleashClientPrototype);
+      unleashClientPrototype.isEnabled = new Proxy(
+        originalIsEnabled,
+        sentryIsEnabled
+      );
     },
   };
 }) satisfies IntegrationFn;
+
diff --git a/packages/browser/src/integrations/featureFlags/unleash/types.ts b/packages/browser/src/integrations/featureFlags/unleash/types.ts
index 520bfcbdc182..8ba56246e7ac 100644
--- a/packages/browser/src/integrations/featureFlags/unleash/types.ts
+++ b/packages/browser/src/integrations/featureFlags/unleash/types.ts
@@ -1,11 +1,16 @@
-export type Variant = {
-  variantName: string;
+export interface IVariant {
+  name: string;
   enabled: boolean;
-  payload?: object; // TODO:
-  // TODO:
+  feature_enabled?: boolean;
+  payload?: {
+      type: string;
+      value: string;
+  };
 }
 
 export interface UnleashClient {
-  isEnabled(featureName: string): boolean;
-  getVariant(featureName: string): Variant;
+  isEnabled(this: UnleashClient, featureName: string): boolean;
+  getVariant(this: UnleashClient, featureName: string): IVariant;
 }
+
+export type UnleashClientClass = new (...args: unknown[]) => UnleashClient;

From e02b91b2b8b24184dac7ea8536cf262049803067 Mon Sep 17 00:00:00 2001
From: Andrew Liu <159852527+aliu39@users.noreply.github.com>
Date: Wed, 8 Jan 2025 16:22:09 -0800
Subject: [PATCH 03/19] Biome check

---
 .../integrations/featureFlags/unleash/integration.ts   | 10 +++-------
 .../src/integrations/featureFlags/unleash/types.ts     |  4 ++--
 2 files changed, 5 insertions(+), 9 deletions(-)

diff --git a/packages/browser/src/integrations/featureFlags/unleash/integration.ts b/packages/browser/src/integrations/featureFlags/unleash/integration.ts
index 470f70cb9924..6362d95e39cc 100644
--- a/packages/browser/src/integrations/featureFlags/unleash/integration.ts
+++ b/packages/browser/src/integrations/featureFlags/unleash/integration.ts
@@ -33,20 +33,16 @@ export const unleashIntegration = defineIntegration((unleashClientClass: Unleash
         apply: (
           target: (this: UnleashClient, toggleName: string) => boolean,
           thisArg: UnleashClient,
-          args: [toggleName: string]
+          args: [toggleName: string],
         ) => {
           const result = Reflect.apply(target, thisArg, args);
           insertFlagToScope(args[0], result);
           return result;
-        }
+        },
       };
       const unleashClientPrototype = unleashClientClass.prototype as UnleashClient;
       const originalIsEnabled = unleashClientPrototype.isEnabled.bind(unleashClientPrototype);
-      unleashClientPrototype.isEnabled = new Proxy(
-        originalIsEnabled,
-        sentryIsEnabled
-      );
+      unleashClientPrototype.isEnabled = new Proxy(originalIsEnabled, sentryIsEnabled);
     },
   };
 }) satisfies IntegrationFn;
-
diff --git a/packages/browser/src/integrations/featureFlags/unleash/types.ts b/packages/browser/src/integrations/featureFlags/unleash/types.ts
index 8ba56246e7ac..8fc3c57843dd 100644
--- a/packages/browser/src/integrations/featureFlags/unleash/types.ts
+++ b/packages/browser/src/integrations/featureFlags/unleash/types.ts
@@ -3,8 +3,8 @@ export interface IVariant {
   enabled: boolean;
   feature_enabled?: boolean;
   payload?: {
-      type: string;
-      value: string;
+    type: string;
+    value: string;
   };
 }
 

From 7ec8d02ef72dc0a9d2023913d46a8a4e0f154448 Mon Sep 17 00:00:00 2001
From: Andrew Liu <159852527+aliu39@users.noreply.github.com>
Date: Wed, 8 Jan 2025 16:29:33 -0800
Subject: [PATCH 04/19] Working patch and test for getVariant

---
 .../featureFlags/unleash/basic/test.ts        | 42 ++++++++++++++++++-
 .../featureFlags/unleash/integration.ts       | 32 +++++++++++---
 2 files changed, 68 insertions(+), 6 deletions(-)

diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/basic/test.ts b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/basic/test.ts
index 79361c137128..283b934a4e96 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/basic/test.ts
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/basic/test.ts
@@ -6,7 +6,7 @@ import { envelopeRequestParser, shouldSkipFeatureFlagsTest, waitForErrorRequest
 
 const FLAG_BUFFER_SIZE = 100; // Corresponds to constant in featureFlags.ts, in browser utils.
 
-sentryTest('Basic test with eviction, update, and no async tasks', async ({ getLocalTestUrl, page }) => {
+sentryTest('Basic isEnabled test with eviction, update, and no async tasks', async ({ getLocalTestUrl, page }) => {
   if (shouldSkipFeatureFlagsTest()) {
     sentryTest.skip();
   }
@@ -45,3 +45,43 @@ sentryTest('Basic test with eviction, update, and no async tasks', async ({ getL
 
   expect(event.contexts?.flags?.values).toEqual(expectedFlags);
 });
+
+sentryTest('Basic getVariant test with eviction, update, and no async tasks', async ({ getLocalTestUrl, page }) => {
+  if (shouldSkipFeatureFlagsTest()) {
+    sentryTest.skip();
+  }
+
+  await page.route('https://dsn.ingest.sentry.io/**/*', route => {
+    return route.fulfill({
+      status: 200,
+      contentType: 'application/json',
+      body: JSON.stringify({ id: 'test-id' }),
+    });
+  });
+
+  const url = await getLocalTestUrl({ testDir: __dirname, skipDsnRouteHandler: true });
+  await page.goto(url);
+
+  await page.evaluate(bufferSize => {
+    const client = new (window as any).UnleashClient();
+    for (let i = 1; i <= bufferSize; i++) {
+      client.getVariant(`feat${i}`);
+    }
+    client.getVariant(`feat${bufferSize + 1}`); // eviction
+    client.getVariant('feat3'); // update
+  }, FLAG_BUFFER_SIZE);
+
+  const reqPromise = waitForErrorRequest(page);
+  await page.locator('#error').click();
+  const req = await reqPromise;
+  const event = envelopeRequestParser(req);
+
+  const expectedFlags = [{ flag: 'feat2', result: false }];
+  for (let i = 4; i <= FLAG_BUFFER_SIZE; i++) {
+    expectedFlags.push({ flag: `feat${i}`, result: false });
+  }
+  expectedFlags.push({ flag: `feat${FLAG_BUFFER_SIZE + 1}`, result: false });
+  expectedFlags.push({ flag: 'feat3', result: false });
+
+  expect(event.contexts?.flags?.values).toEqual(expectedFlags);
+});
diff --git a/packages/browser/src/integrations/featureFlags/unleash/integration.ts b/packages/browser/src/integrations/featureFlags/unleash/integration.ts
index 6362d95e39cc..75be61d19e11 100644
--- a/packages/browser/src/integrations/featureFlags/unleash/integration.ts
+++ b/packages/browser/src/integrations/featureFlags/unleash/integration.ts
@@ -2,22 +2,28 @@ import type { Client, Event, EventHint, IntegrationFn } from '@sentry/core';
 
 import { defineIntegration } from '@sentry/core';
 import { copyFlagsFromScopeToEvent, insertFlagToScope } from '../../../utils/featureFlags';
-import type { UnleashClient, UnleashClientClass } from './types';
+import type { IVariant, UnleashClient, UnleashClientClass } from './types';
 
 /**
- * Sentry integration for capturing feature flags from the Unleash SDK.
+ * Sentry integration for capturing feature flag evaluations from the Unleash SDK.
  *
  * See the [feature flag documentation](https://develop.sentry.dev/sdk/expected-features/#feature-flags) for more information.
  *
  * @example
  * ```
+ * import { UnleashClient } from 'unleash-proxy-client';
  * import * as Sentry from '@sentry/browser';
- * TODO:
+ *
+ * const unleashIntegration = Sentry.unleashIntegration(UnleashClient);
  *
  * Sentry.init({
  *   dsn: '___PUBLIC_DSN___',
- *   integrations: [TODO:]
+ *   integrations: [unleashIntegration],
  * });
+ *
+ * const unleashClient = new UnleashClient(...);
+ * unleashClient.isEnabled('my-feature');
+ * Sentry.captureException(new Error('something went wrong'));
  * ```
  */
 export const unleashIntegration = defineIntegration((unleashClientClass: UnleashClientClass) => {
@@ -29,6 +35,8 @@ export const unleashIntegration = defineIntegration((unleashClientClass: Unleash
     },
 
     setupOnce() {
+      const unleashClientPrototype = unleashClientClass.prototype as UnleashClient;
+
       const sentryIsEnabled = {
         apply: (
           target: (this: UnleashClient, toggleName: string) => boolean,
@@ -40,9 +48,23 @@ export const unleashIntegration = defineIntegration((unleashClientClass: Unleash
           return result;
         },
       };
-      const unleashClientPrototype = unleashClientClass.prototype as UnleashClient;
       const originalIsEnabled = unleashClientPrototype.isEnabled.bind(unleashClientPrototype);
       unleashClientPrototype.isEnabled = new Proxy(originalIsEnabled, sentryIsEnabled);
+
+      const sentryGetVariant = {
+        apply: (
+          target: (this: UnleashClient, toggleName: string) => IVariant,
+          thisArg: UnleashClient,
+          args: [toggleName: string],
+        ) => {
+          const variant = Reflect.apply(target, thisArg, args);
+          const result = variant.enabled;
+          insertFlagToScope(args[0], result);
+          return variant;
+        },
+      };
+      const originalGetVariant = unleashClientPrototype.getVariant.bind(unleashClientPrototype);
+      unleashClientPrototype.getVariant = new Proxy(originalGetVariant, sentryGetVariant);
     },
   };
 }) satisfies IntegrationFn;

From f1a5574a82ac2aeaff037bca4dedf7f9169abe77 Mon Sep 17 00:00:00 2001
From: Andrew Liu <159852527+aliu39@users.noreply.github.com>
Date: Thu, 9 Jan 2025 15:02:01 -0800
Subject: [PATCH 05/19] Fix docstr sample code

---
 .../suites/integrations/featureFlags/unleash/init.js       | 2 --
 .../src/integrations/featureFlags/unleash/integration.ts   | 7 +++++--
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/init.js b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/init.js
index f40861483bea..149fb9bd4ae5 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/init.js
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/init.js
@@ -21,5 +21,3 @@ Sentry.init({
   sampleRate: 1.0,
   integrations: [window.sentryUnleashIntegration],
 });
-
-
diff --git a/packages/browser/src/integrations/featureFlags/unleash/integration.ts b/packages/browser/src/integrations/featureFlags/unleash/integration.ts
index 75be61d19e11..344e110ddc4d 100644
--- a/packages/browser/src/integrations/featureFlags/unleash/integration.ts
+++ b/packages/browser/src/integrations/featureFlags/unleash/integration.ts
@@ -21,8 +21,11 @@ import type { IVariant, UnleashClient, UnleashClientClass } from './types';
  *   integrations: [unleashIntegration],
  * });
  *
- * const unleashClient = new UnleashClient(...);
- * unleashClient.isEnabled('my-feature');
+ * const unleash = new UnleashClient(...);
+ * unleash.start();
+ *
+ * unleash.isEnabled('my-feature');
+ * unleash.getVariant('other-feature');
  * Sentry.captureException(new Error('something went wrong'));
  * ```
  */

From 34af880ed0769e04e01d8ce06ae822d49ad4e144 Mon Sep 17 00:00:00 2001
From: Andrew Liu <159852527+aliu39@users.noreply.github.com>
Date: Thu, 9 Jan 2025 15:56:37 -0800
Subject: [PATCH 06/19] Fix patching for correct access to

---
 .../featureFlags/unleash/basic/test.ts        | 16 +++++---
 .../integrations/featureFlags/unleash/init.js | 37 ++++++++++++++++---
 .../featureFlags/unleash/integration.ts       |  6 +--
 3 files changed, 45 insertions(+), 14 deletions(-)

diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/basic/test.ts b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/basic/test.ts
index 283b934a4e96..d58c346e4c18 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/basic/test.ts
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/basic/test.ts
@@ -36,12 +36,14 @@ sentryTest('Basic isEnabled test with eviction, update, and no async tasks', asy
   const req = await reqPromise;
   const event = envelopeRequestParser(req);
 
-  const expectedFlags = [{ flag: 'feat2', result: false }];
-  for (let i = 4; i <= FLAG_BUFFER_SIZE; i++) {
+  const expectedFlags = [{ flag: 'feat2', result: true }];
+  expectedFlags.push({ flag: 'feat4', result: true });
+  expectedFlags.push({ flag: 'feat5', result: true });
+  for (let i = 6; i <= FLAG_BUFFER_SIZE; i++) {
     expectedFlags.push({ flag: `feat${i}`, result: false });
   }
   expectedFlags.push({ flag: `feat${FLAG_BUFFER_SIZE + 1}`, result: false });
-  expectedFlags.push({ flag: 'feat3', result: false });
+  expectedFlags.push({ flag: 'feat3', result: true });
 
   expect(event.contexts?.flags?.values).toEqual(expectedFlags);
 });
@@ -76,12 +78,14 @@ sentryTest('Basic getVariant test with eviction, update, and no async tasks', as
   const req = await reqPromise;
   const event = envelopeRequestParser(req);
 
-  const expectedFlags = [{ flag: 'feat2', result: false }];
-  for (let i = 4; i <= FLAG_BUFFER_SIZE; i++) {
+  const expectedFlags = [{ flag: 'feat2', result: true }];
+  expectedFlags.push({ flag: 'feat4', result: true });
+  expectedFlags.push({ flag: 'feat5', result: true });
+  for (let i = 6; i <= FLAG_BUFFER_SIZE; i++) {
     expectedFlags.push({ flag: `feat${i}`, result: false });
   }
   expectedFlags.push({ flag: `feat${FLAG_BUFFER_SIZE + 1}`, result: false });
-  expectedFlags.push({ flag: 'feat3', result: false });
+  expectedFlags.push({ flag: 'feat3', result: true });
 
   expect(event.contexts?.flags?.values).toEqual(expectedFlags);
 });
diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/init.js b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/init.js
index 149fb9bd4ae5..74f919346f90 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/init.js
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/init.js
@@ -1,16 +1,43 @@
 import * as Sentry from '@sentry/browser';
 
 window.UnleashClient = class {
-  isEnabled(_toggleName) {
-    return false;
-  }
+  constructor() {
+    this._featureToVariant = {
+      'feat2': {name: 'variant1', enabled: true, feature_enabled: true, payload: {type: 'string', value: 'test'}},
+      'feat3': {name: 'eu-west', enabled: true, feature_enabled: true},
+      'feat4': {
+        name: 'paid-orgs',
+        enabled: true,
+        feature_enabled: true,
+        payload: {
+          type: 'json',
+          value: '{"foo": {"bar": "baz"}, "hello": [1, 2, 3]}',
+        },
+      },
+
+      // Enabled feature with no configured variants.
+      'feat5': {name: 'disabled', enabled: false, feature_enabled: true},
+
+      // Disabled feature.
+      'feat6': {name: 'disabled', enabled: false, feature_enabled: false},
+    };
 
-  getVariant(_toggleName) {
-    return {
+    // Variant returned for features that don't exist.
+    // `feature_enabled` may be defined in prod, but we want to test the undefined case.
+    this._fallbackVariant = {
       name: 'disabled',
       enabled: false,
     };
   }
+
+  isEnabled(toggleName) {
+    const variant = this._featureToVariant[toggleName] || this._fallbackVariant;
+    return variant.feature_enabled || false;
+  }
+
+  getVariant(toggleName) {
+    return this._featureToVariant[toggleName] || this._fallbackVariant;
+  }
 };
 
 window.Sentry = Sentry;
diff --git a/packages/browser/src/integrations/featureFlags/unleash/integration.ts b/packages/browser/src/integrations/featureFlags/unleash/integration.ts
index 344e110ddc4d..9b8268426af0 100644
--- a/packages/browser/src/integrations/featureFlags/unleash/integration.ts
+++ b/packages/browser/src/integrations/featureFlags/unleash/integration.ts
@@ -51,7 +51,7 @@ export const unleashIntegration = defineIntegration((unleashClientClass: Unleash
           return result;
         },
       };
-      const originalIsEnabled = unleashClientPrototype.isEnabled.bind(unleashClientPrototype);
+      const originalIsEnabled = unleashClientPrototype.isEnabled;
       unleashClientPrototype.isEnabled = new Proxy(originalIsEnabled, sentryIsEnabled);
 
       const sentryGetVariant = {
@@ -61,12 +61,12 @@ export const unleashIntegration = defineIntegration((unleashClientClass: Unleash
           args: [toggleName: string],
         ) => {
           const variant = Reflect.apply(target, thisArg, args);
-          const result = variant.enabled;
+          const result = variant.feature_enabled || false; // undefined means the feature does not exist.
           insertFlagToScope(args[0], result);
           return variant;
         },
       };
-      const originalGetVariant = unleashClientPrototype.getVariant.bind(unleashClientPrototype);
+      const originalGetVariant = unleashClientPrototype.getVariant;
       unleashClientPrototype.getVariant = new Proxy(originalGetVariant, sentryGetVariant);
     },
   };

From c8b0078305379606f0e03b0b7a359d09c319751f Mon Sep 17 00:00:00 2001
From: Andrew Liu <159852527+aliu39@users.noreply.github.com>
Date: Thu, 9 Jan 2025 15:59:31 -0800
Subject: [PATCH 07/19] ini.js format

---
 .../suites/integrations/featureFlags/unleash/init.js   | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/init.js b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/init.js
index 74f919346f90..b387706c6ee6 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/init.js
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/init.js
@@ -3,9 +3,9 @@ import * as Sentry from '@sentry/browser';
 window.UnleashClient = class {
   constructor() {
     this._featureToVariant = {
-      'feat2': {name: 'variant1', enabled: true, feature_enabled: true, payload: {type: 'string', value: 'test'}},
-      'feat3': {name: 'eu-west', enabled: true, feature_enabled: true},
-      'feat4': {
+      feat2: {name: 'variant1', enabled: true, feature_enabled: true, payload: {type: 'string', value: 'test'}},
+      feat3: {name: 'eu-west', enabled: true, feature_enabled: true},
+      feat4: {
         name: 'paid-orgs',
         enabled: true,
         feature_enabled: true,
@@ -16,10 +16,10 @@ window.UnleashClient = class {
       },
 
       // Enabled feature with no configured variants.
-      'feat5': {name: 'disabled', enabled: false, feature_enabled: true},
+      feat5: {name: 'disabled', enabled: false, feature_enabled: true},
 
       // Disabled feature.
-      'feat6': {name: 'disabled', enabled: false, feature_enabled: false},
+      feat6: {name: 'disabled', enabled: false, feature_enabled: false},
     };
 
     // Variant returned for features that don't exist.

From 2543733713e52d2099d27561711c99f0e1b5d169 Mon Sep 17 00:00:00 2001
From: Andrew Liu <159852527+aliu39@users.noreply.github.com>
Date: Thu, 9 Jan 2025 16:04:13 -0800
Subject: [PATCH 08/19] init.js format2

---
 .../suites/integrations/featureFlags/unleash/init.js      | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/init.js b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/init.js
index b387706c6ee6..c73f544d0724 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/init.js
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/init.js
@@ -3,8 +3,8 @@ import * as Sentry from '@sentry/browser';
 window.UnleashClient = class {
   constructor() {
     this._featureToVariant = {
-      feat2: {name: 'variant1', enabled: true, feature_enabled: true, payload: {type: 'string', value: 'test'}},
-      feat3: {name: 'eu-west', enabled: true, feature_enabled: true},
+      feat2: { name: 'variant1', enabled: true, feature_enabled: true, payload: { type: 'string', value: 'test' } },
+      feat3: { name: 'eu-west', enabled: true, feature_enabled: true },
       feat4: {
         name: 'paid-orgs',
         enabled: true,
@@ -16,10 +16,10 @@ window.UnleashClient = class {
       },
 
       // Enabled feature with no configured variants.
-      feat5: {name: 'disabled', enabled: false, feature_enabled: true},
+      feat5: { name: 'disabled', enabled: false, feature_enabled: true },
 
       // Disabled feature.
-      feat6: {name: 'disabled', enabled: false, feature_enabled: false},
+      feat6: { name: 'disabled', enabled: false, feature_enabled: false },
     };
 
     // Variant returned for features that don't exist.

From 211a1ab2935ca8a2afd13006bb49b42e5100339a Mon Sep 17 00:00:00 2001
From: Andrew Liu <159852527+aliu39@users.noreply.github.com>
Date: Fri, 10 Jan 2025 00:48:19 -0800
Subject: [PATCH 09/19] Disable eslint/unbound-method

---
 .../src/integrations/featureFlags/unleash/integration.ts        | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/packages/browser/src/integrations/featureFlags/unleash/integration.ts b/packages/browser/src/integrations/featureFlags/unleash/integration.ts
index 9b8268426af0..607fa6c05a1a 100644
--- a/packages/browser/src/integrations/featureFlags/unleash/integration.ts
+++ b/packages/browser/src/integrations/featureFlags/unleash/integration.ts
@@ -51,6 +51,7 @@ export const unleashIntegration = defineIntegration((unleashClientClass: Unleash
           return result;
         },
       };
+      // eslint-disable-next-line @typescript-eslint/unbound-method
       const originalIsEnabled = unleashClientPrototype.isEnabled;
       unleashClientPrototype.isEnabled = new Proxy(originalIsEnabled, sentryIsEnabled);
 
@@ -66,6 +67,7 @@ export const unleashIntegration = defineIntegration((unleashClientClass: Unleash
           return variant;
         },
       };
+      // eslint-disable-next-line @typescript-eslint/unbound-method
       const originalGetVariant = unleashClientPrototype.getVariant;
       unleashClientPrototype.getVariant = new Proxy(originalGetVariant, sentryGetVariant);
     },

From 2898386b6f0d1d9f35a1ee61eaf6796a5e0ab651 Mon Sep 17 00:00:00 2001
From: Andrew Liu <159852527+aliu39@users.noreply.github.com>
Date: Fri, 10 Jan 2025 12:21:19 -0800
Subject: [PATCH 10/19] Rm getVariant code

---
 .../featureFlags/unleash/basic/test.ts        | 44 +------------------
 .../featureFlags/unleash/integration.ts       | 18 +-------
 2 files changed, 2 insertions(+), 60 deletions(-)

diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/basic/test.ts b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/basic/test.ts
index d58c346e4c18..dc2dee988fef 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/basic/test.ts
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/basic/test.ts
@@ -6,7 +6,7 @@ import { envelopeRequestParser, shouldSkipFeatureFlagsTest, waitForErrorRequest
 
 const FLAG_BUFFER_SIZE = 100; // Corresponds to constant in featureFlags.ts, in browser utils.
 
-sentryTest('Basic isEnabled test with eviction, update, and no async tasks', async ({ getLocalTestUrl, page }) => {
+sentryTest('Basic test with eviction, update, and no async tasks', async ({ getLocalTestUrl, page }) => {
   if (shouldSkipFeatureFlagsTest()) {
     sentryTest.skip();
   }
@@ -47,45 +47,3 @@ sentryTest('Basic isEnabled test with eviction, update, and no async tasks', asy
 
   expect(event.contexts?.flags?.values).toEqual(expectedFlags);
 });
-
-sentryTest('Basic getVariant test with eviction, update, and no async tasks', async ({ getLocalTestUrl, page }) => {
-  if (shouldSkipFeatureFlagsTest()) {
-    sentryTest.skip();
-  }
-
-  await page.route('https://dsn.ingest.sentry.io/**/*', route => {
-    return route.fulfill({
-      status: 200,
-      contentType: 'application/json',
-      body: JSON.stringify({ id: 'test-id' }),
-    });
-  });
-
-  const url = await getLocalTestUrl({ testDir: __dirname, skipDsnRouteHandler: true });
-  await page.goto(url);
-
-  await page.evaluate(bufferSize => {
-    const client = new (window as any).UnleashClient();
-    for (let i = 1; i <= bufferSize; i++) {
-      client.getVariant(`feat${i}`);
-    }
-    client.getVariant(`feat${bufferSize + 1}`); // eviction
-    client.getVariant('feat3'); // update
-  }, FLAG_BUFFER_SIZE);
-
-  const reqPromise = waitForErrorRequest(page);
-  await page.locator('#error').click();
-  const req = await reqPromise;
-  const event = envelopeRequestParser(req);
-
-  const expectedFlags = [{ flag: 'feat2', result: true }];
-  expectedFlags.push({ flag: 'feat4', result: true });
-  expectedFlags.push({ flag: 'feat5', result: true });
-  for (let i = 6; i <= FLAG_BUFFER_SIZE; i++) {
-    expectedFlags.push({ flag: `feat${i}`, result: false });
-  }
-  expectedFlags.push({ flag: `feat${FLAG_BUFFER_SIZE + 1}`, result: false });
-  expectedFlags.push({ flag: 'feat3', result: true });
-
-  expect(event.contexts?.flags?.values).toEqual(expectedFlags);
-});
diff --git a/packages/browser/src/integrations/featureFlags/unleash/integration.ts b/packages/browser/src/integrations/featureFlags/unleash/integration.ts
index 607fa6c05a1a..886afab01884 100644
--- a/packages/browser/src/integrations/featureFlags/unleash/integration.ts
+++ b/packages/browser/src/integrations/featureFlags/unleash/integration.ts
@@ -2,7 +2,7 @@ import type { Client, Event, EventHint, IntegrationFn } from '@sentry/core';
 
 import { defineIntegration } from '@sentry/core';
 import { copyFlagsFromScopeToEvent, insertFlagToScope } from '../../../utils/featureFlags';
-import type { IVariant, UnleashClient, UnleashClientClass } from './types';
+import type { UnleashClient, UnleashClientClass } from './types';
 
 /**
  * Sentry integration for capturing feature flag evaluations from the Unleash SDK.
@@ -54,22 +54,6 @@ export const unleashIntegration = defineIntegration((unleashClientClass: Unleash
       // eslint-disable-next-line @typescript-eslint/unbound-method
       const originalIsEnabled = unleashClientPrototype.isEnabled;
       unleashClientPrototype.isEnabled = new Proxy(originalIsEnabled, sentryIsEnabled);
-
-      const sentryGetVariant = {
-        apply: (
-          target: (this: UnleashClient, toggleName: string) => IVariant,
-          thisArg: UnleashClient,
-          args: [toggleName: string],
-        ) => {
-          const variant = Reflect.apply(target, thisArg, args);
-          const result = variant.feature_enabled || false; // undefined means the feature does not exist.
-          insertFlagToScope(args[0], result);
-          return variant;
-        },
-      };
-      // eslint-disable-next-line @typescript-eslint/unbound-method
-      const originalGetVariant = unleashClientPrototype.getVariant;
-      unleashClientPrototype.getVariant = new Proxy(originalGetVariant, sentryGetVariant);
     },
   };
 }) satisfies IntegrationFn;

From b972f6e7e6275519161c418e75377ff8b49b4947 Mon Sep 17 00:00:00 2001
From: Andrew Liu <159852527+aliu39@users.noreply.github.com>
Date: Fri, 10 Jan 2025 12:37:07 -0800
Subject: [PATCH 11/19] Add withScope test

---
 .../featureFlags/unleash/basic/test.ts        | 23 +++++--
 .../integrations/featureFlags/unleash/init.js | 10 +--
 .../featureFlags/unleash/withScope/test.ts    | 65 +++++++++++++++++++
 3 files changed, 86 insertions(+), 12 deletions(-)
 create mode 100644 dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/withScope/test.ts

diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/basic/test.ts b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/basic/test.ts
index dc2dee988fef..5bb72caddd24 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/basic/test.ts
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/basic/test.ts
@@ -24,11 +24,19 @@ sentryTest('Basic test with eviction, update, and no async tasks', async ({ getL
 
   await page.evaluate(bufferSize => {
     const client = new (window as any).UnleashClient();
-    for (let i = 1; i <= bufferSize; i++) {
+
+    client.isEnabled('feat1');
+    client.isEnabled('strFeat');
+    client.isEnabled('noPayloadFeat');
+    client.isEnabled('jsonFeat');
+    client.isEnabled('noVariantFeat');
+    client.isEnabled('disabledFeat');
+
+    for (let i = 7; i <= bufferSize; i++) {
       client.isEnabled(`feat${i}`);
     }
     client.isEnabled(`feat${bufferSize + 1}`); // eviction
-    client.isEnabled('feat3'); // update
+    client.isEnabled('noPayloadFeat'); // update (move to tail)
   }, FLAG_BUFFER_SIZE);
 
   const reqPromise = waitForErrorRequest(page);
@@ -36,14 +44,15 @@ sentryTest('Basic test with eviction, update, and no async tasks', async ({ getL
   const req = await reqPromise;
   const event = envelopeRequestParser(req);
 
-  const expectedFlags = [{ flag: 'feat2', result: true }];
-  expectedFlags.push({ flag: 'feat4', result: true });
-  expectedFlags.push({ flag: 'feat5', result: true });
-  for (let i = 6; i <= FLAG_BUFFER_SIZE; i++) {
+  const expectedFlags = [{ flag: 'strFeat', result: true }];
+  expectedFlags.push({ flag: 'jsonFeat', result: true });
+  expectedFlags.push({ flag: 'noVariantFeat', result: true });
+  expectedFlags.push({ flag: 'disabledFeat', result: false });
+  for (let i = 7; i <= FLAG_BUFFER_SIZE; i++) {
     expectedFlags.push({ flag: `feat${i}`, result: false });
   }
   expectedFlags.push({ flag: `feat${FLAG_BUFFER_SIZE + 1}`, result: false });
-  expectedFlags.push({ flag: 'feat3', result: true });
+  expectedFlags.push({ flag: 'noPayloadFeat', result: true });
 
   expect(event.contexts?.flags?.values).toEqual(expectedFlags);
 });
diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/init.js b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/init.js
index c73f544d0724..301f8da7ad50 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/init.js
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/init.js
@@ -3,9 +3,9 @@ import * as Sentry from '@sentry/browser';
 window.UnleashClient = class {
   constructor() {
     this._featureToVariant = {
-      feat2: { name: 'variant1', enabled: true, feature_enabled: true, payload: { type: 'string', value: 'test' } },
-      feat3: { name: 'eu-west', enabled: true, feature_enabled: true },
-      feat4: {
+      strFeat: { name: 'variant1', enabled: true, feature_enabled: true, payload: { type: 'string', value: 'test' } },
+      noPayloadFeat: { name: 'eu-west', enabled: true, feature_enabled: true },
+      jsonFeat: {
         name: 'paid-orgs',
         enabled: true,
         feature_enabled: true,
@@ -16,10 +16,10 @@ window.UnleashClient = class {
       },
 
       // Enabled feature with no configured variants.
-      feat5: { name: 'disabled', enabled: false, feature_enabled: true },
+      noVariantFeat: { name: 'disabled', enabled: false, feature_enabled: true },
 
       // Disabled feature.
-      feat6: { name: 'disabled', enabled: false, feature_enabled: false },
+      disabledFeat: { name: 'disabled', enabled: false, feature_enabled: false },
     };
 
     // Variant returned for features that don't exist.
diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/withScope/test.ts b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/withScope/test.ts
new file mode 100644
index 000000000000..2d821bf6c81d
--- /dev/null
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/withScope/test.ts
@@ -0,0 +1,65 @@
+import { expect } from '@playwright/test';
+
+import { sentryTest } from '../../../../../utils/fixtures';
+
+import { envelopeRequestParser, shouldSkipFeatureFlagsTest, waitForErrorRequest } from '../../../../../utils/helpers';
+
+import type { Scope } from '@sentry/browser';
+
+sentryTest('Flag evaluations in forked scopes are stored separately.', async ({ getLocalTestUrl, page }) => {
+  if (shouldSkipFeatureFlagsTest()) {
+    sentryTest.skip();
+  }
+
+  await page.route('https://dsn.ingest.sentry.io/**/*', route => {
+    return route.fulfill({
+      status: 200,
+      contentType: 'application/json',
+      body: JSON.stringify({ id: 'test-id' }),
+    });
+  });
+
+  const url = await getLocalTestUrl({ testDir: __dirname, skipDsnRouteHandler: true });
+  await page.goto(url);
+
+  const forkedReqPromise = waitForErrorRequest(page, event => !!event.tags && event.tags.isForked === true);
+  const mainReqPromise = waitForErrorRequest(page, event => !!event.tags && event.tags.isForked === false);
+
+  await page.evaluate(() => {
+    const Sentry = (window as any).Sentry;
+    const errorButton = document.querySelector('#error') as HTMLButtonElement;
+    const unleash = new (window as any).UnleashClient();
+
+    unleash.isEnabled('strFeat');
+
+    Sentry.withScope((scope: Scope) => {
+      unleash.isEnabled('disabledFeat');
+      unleash.isEnabled('strFeat');
+      scope.setTag('isForked', true);
+      if (errorButton) {
+        errorButton.click();
+      }
+    });
+
+    unleash.isEnabled('noPayloadFeat');
+    Sentry.getCurrentScope().setTag('isForked', false);
+    errorButton.click();
+    return true;
+  });
+
+  const forkedReq = await forkedReqPromise;
+  const forkedEvent = envelopeRequestParser(forkedReq);
+
+  const mainReq = await mainReqPromise;
+  const mainEvent = envelopeRequestParser(mainReq);
+
+  expect(forkedEvent.contexts?.flags?.values).toEqual([
+    { flag: 'disabledFeat', result: false },
+    { flag: 'strFeat', result: true },
+  ]);
+
+  expect(mainEvent.contexts?.flags?.values).toEqual([
+    { flag: 'strFeat', result: true },
+    { flag: 'noPayloadFeat', result: true },
+  ]);
+});

From dbf0f64bc7ce72aa8775ee3f1b1478cf4c3d216f Mon Sep 17 00:00:00 2001
From: Andrew Liu <159852527+aliu39@users.noreply.github.com>
Date: Wed, 15 Jan 2025 10:29:19 -0800
Subject: [PATCH 12/19] Rewrite patching with fill()

---
 .../featureFlags/unleash/integration.ts       | 39 +++++++++++--------
 1 file changed, 23 insertions(+), 16 deletions(-)

diff --git a/packages/browser/src/integrations/featureFlags/unleash/integration.ts b/packages/browser/src/integrations/featureFlags/unleash/integration.ts
index 886afab01884..eb7df04b8a2e 100644
--- a/packages/browser/src/integrations/featureFlags/unleash/integration.ts
+++ b/packages/browser/src/integrations/featureFlags/unleash/integration.ts
@@ -1,6 +1,6 @@
 import type { Client, Event, EventHint, IntegrationFn } from '@sentry/core';
 
-import { defineIntegration } from '@sentry/core';
+import { defineIntegration, fill, logger } from '@sentry/core';
 import { copyFlagsFromScopeToEvent, insertFlagToScope } from '../../../utils/featureFlags';
 import type { UnleashClient, UnleashClientClass } from './types';
 
@@ -39,21 +39,28 @@ export const unleashIntegration = defineIntegration((unleashClientClass: Unleash
 
     setupOnce() {
       const unleashClientPrototype = unleashClientClass.prototype as UnleashClient;
-
-      const sentryIsEnabled = {
-        apply: (
-          target: (this: UnleashClient, toggleName: string) => boolean,
-          thisArg: UnleashClient,
-          args: [toggleName: string],
-        ) => {
-          const result = Reflect.apply(target, thisArg, args);
-          insertFlagToScope(args[0], result);
-          return result;
-        },
-      };
-      // eslint-disable-next-line @typescript-eslint/unbound-method
-      const originalIsEnabled = unleashClientPrototype.isEnabled;
-      unleashClientPrototype.isEnabled = new Proxy(originalIsEnabled, sentryIsEnabled);
+      fill(unleashClientPrototype, 'isEnabled', _wrappedIsEnabled);
     },
   };
 }) satisfies IntegrationFn;
+
+/**
+ * Wraps the UnleashClient.isEnabled method to capture feature flag evaluations. Its only side effect is writing to Sentry scope.
+ *
+ * @param original - The original method.
+ * @returns Wrapped method. Results should match the original.
+ */
+function _wrappedIsEnabled(original: (this: UnleashClient, ...args: unknown[]) => unknown): (this: UnleashClient, ...args: unknown[]) => unknown {
+  return function (this: UnleashClient, ...args: unknown[]): unknown {
+    const toggleName = args[0];
+    const result = original.apply(this, args);
+
+    if (typeof toggleName === 'string' && typeof result === 'boolean') {
+      insertFlagToScope(toggleName, result);
+    } else {
+      // TODO: test this branch
+      logger.error(`[Feature Flags] UnleashClient.isEnabled does not match expected signature. arg0: ${toggleName} (${typeof toggleName}), result: ${result} (${typeof result})`);
+    }
+    return result;
+  };
+}

From ba090a28efc69768ae5cf908548ef4a931b3b4da Mon Sep 17 00:00:00 2001
From: Andrew Liu <159852527+aliu39@users.noreply.github.com>
Date: Wed, 15 Jan 2025 10:46:59 -0800
Subject: [PATCH 13/19] Change integration input to an options dict

---
 .../suites/integrations/featureFlags/unleash/init.js          | 2 +-
 .../src/integrations/featureFlags/unleash/integration.ts      | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/init.js b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/init.js
index 301f8da7ad50..2a991bfde3f0 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/init.js
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/init.js
@@ -41,7 +41,7 @@ window.UnleashClient = class {
 };
 
 window.Sentry = Sentry;
-window.sentryUnleashIntegration = Sentry.unleashIntegration(window.UnleashClient);
+window.sentryUnleashIntegration = Sentry.unleashIntegration({unleashClientClass: window.UnleashClient});
 
 Sentry.init({
   dsn: 'https://public@dsn.ingest.sentry.io/1337',
diff --git a/packages/browser/src/integrations/featureFlags/unleash/integration.ts b/packages/browser/src/integrations/featureFlags/unleash/integration.ts
index eb7df04b8a2e..608ca4200eb3 100644
--- a/packages/browser/src/integrations/featureFlags/unleash/integration.ts
+++ b/packages/browser/src/integrations/featureFlags/unleash/integration.ts
@@ -14,7 +14,7 @@ import type { UnleashClient, UnleashClientClass } from './types';
  * import { UnleashClient } from 'unleash-proxy-client';
  * import * as Sentry from '@sentry/browser';
  *
- * const unleashIntegration = Sentry.unleashIntegration(UnleashClient);
+ * const unleashIntegration = Sentry.unleashIntegration({unleashClientClass: UnleashClient});
  *
  * Sentry.init({
  *   dsn: '___PUBLIC_DSN___',
@@ -29,7 +29,7 @@ import type { UnleashClient, UnleashClientClass } from './types';
  * Sentry.captureException(new Error('something went wrong'));
  * ```
  */
-export const unleashIntegration = defineIntegration((unleashClientClass: UnleashClientClass) => {
+export const unleashIntegration = defineIntegration(({unleashClientClass}: {unleashClientClass: UnleashClientClass}) => {
   return {
     name: 'Unleash',
 

From bba93f7b00c52f85f75a26e45a75ab237729a502 Mon Sep 17 00:00:00 2001
From: Andrew Liu <159852527+aliu39@users.noreply.github.com>
Date: Wed, 15 Jan 2025 10:54:33 -0800
Subject: [PATCH 14/19] Update wrapper docstr

---
 .../src/integrations/featureFlags/unleash/integration.ts       | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/packages/browser/src/integrations/featureFlags/unleash/integration.ts b/packages/browser/src/integrations/featureFlags/unleash/integration.ts
index 608ca4200eb3..fe75e53bdcb5 100644
--- a/packages/browser/src/integrations/featureFlags/unleash/integration.ts
+++ b/packages/browser/src/integrations/featureFlags/unleash/integration.ts
@@ -47,6 +47,9 @@ export const unleashIntegration = defineIntegration(({unleashClientClass}: {unle
 /**
  * Wraps the UnleashClient.isEnabled method to capture feature flag evaluations. Its only side effect is writing to Sentry scope.
  *
+ * This wrapper is safe for all isEnabled signatures. If the signature does not match (this: UnleashClient, toggleName: string, ...args: unknown[]) => boolean,
+ * we log an error and return the original result.
+ *
  * @param original - The original method.
  * @returns Wrapped method. Results should match the original.
  */

From 776bb58242a4cc4f64fb41e9bb158284f6ef3416 Mon Sep 17 00:00:00 2001
From: Andrew Liu <159852527+aliu39@users.noreply.github.com>
Date: Wed, 15 Jan 2025 13:11:38 -0800
Subject: [PATCH 15/19] Add badSignature test

---
 .../featureFlags/unleash/badSignature/init.js | 17 +++++++
 .../featureFlags/unleash/badSignature/test.ts | 49 +++++++++++++++++++
 .../featureFlags/unleash/integration.ts       |  1 -
 3 files changed, 66 insertions(+), 1 deletion(-)
 create mode 100644 dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/badSignature/init.js
 create mode 100644 dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/badSignature/test.ts

diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/badSignature/init.js b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/badSignature/init.js
new file mode 100644
index 000000000000..3e9a79894532
--- /dev/null
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/badSignature/init.js
@@ -0,0 +1,17 @@
+import * as Sentry from '@sentry/browser';
+
+window.UnleashClient = class {
+  isEnabled(x) {
+    return x;
+  }
+};
+
+window.Sentry = Sentry;
+window.sentryUnleashIntegration = Sentry.unleashIntegration({unleashClientClass: window.UnleashClient});
+
+Sentry.init({
+  dsn: 'https://public@dsn.ingest.sentry.io/1337',
+  sampleRate: 1.0,
+  integrations: [window.sentryUnleashIntegration],
+  debug: true, // Required to test logging.
+});
diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/badSignature/test.ts b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/badSignature/test.ts
new file mode 100644
index 000000000000..70c25fa8f560
--- /dev/null
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/badSignature/test.ts
@@ -0,0 +1,49 @@
+import { expect } from '@playwright/test';
+
+import { sentryTest } from '../../../../../utils/fixtures';
+
+import { shouldSkipFeatureFlagsTest } from '../../../../../utils/helpers';
+
+sentryTest('Logs and returns if isEnabled does not match expected signature', async ({ getLocalTestUrl, page }) => {
+  if (shouldSkipFeatureFlagsTest()) {
+    sentryTest.skip();
+  }
+
+  await page.route('https://dsn.ingest.sentry.io/**/*', route => {
+    return route.fulfill({
+      status: 200,
+      contentType: 'application/json',
+      body: JSON.stringify({ id: 'test-id' }),
+    });
+  });
+
+  const url = await getLocalTestUrl({ testDir: __dirname, skipDsnRouteHandler: true });
+  await page.goto(url);
+
+  const errorLogs: string[] = [];
+  page.on('console', msg => {
+    if (msg.type() == 'error') {
+      errorLogs.push(msg.text());
+    }
+  });
+
+  const results = await page.evaluate(() => {
+    const unleash = new (window as any).UnleashClient();
+    const res1 = unleash.isEnabled('my-feature');
+    const res2 = unleash.isEnabled(999);
+    const res3 = unleash.isEnabled({});
+    return [res1, res2, res3];
+  });
+
+  // Test that the expected results are still returned. Note isEnabled is identity function for this test.
+  expect(results).toEqual(['my-feature', 999, {}]);
+
+  // Expected error logs.
+  expect(errorLogs).toEqual(
+    expect.arrayContaining([
+      expect.stringContaining('[Feature Flags] UnleashClient.isEnabled does not match expected signature. arg0: my-feature (string), result: my-feature (string)'),
+      expect.stringContaining('[Feature Flags] UnleashClient.isEnabled does not match expected signature. arg0: 999 (number), result: 999 (number)'),
+      expect.stringContaining('[Feature Flags] UnleashClient.isEnabled does not match expected signature. arg0: [object Object] (object), result: [object Object] (object)'),
+    ]),
+  );
+});
diff --git a/packages/browser/src/integrations/featureFlags/unleash/integration.ts b/packages/browser/src/integrations/featureFlags/unleash/integration.ts
index fe75e53bdcb5..29652a1273d8 100644
--- a/packages/browser/src/integrations/featureFlags/unleash/integration.ts
+++ b/packages/browser/src/integrations/featureFlags/unleash/integration.ts
@@ -61,7 +61,6 @@ function _wrappedIsEnabled(original: (this: UnleashClient, ...args: unknown[]) =
     if (typeof toggleName === 'string' && typeof result === 'boolean') {
       insertFlagToScope(toggleName, result);
     } else {
-      // TODO: test this branch
       logger.error(`[Feature Flags] UnleashClient.isEnabled does not match expected signature. arg0: ${toggleName} (${typeof toggleName}), result: ${result} (${typeof result})`);
     }
     return result;

From fae120bd138696da3bbc781b5420a0d557fb5d59 Mon Sep 17 00:00:00 2001
From: Andrew Liu <159852527+aliu39@users.noreply.github.com>
Date: Wed, 15 Jan 2025 13:13:23 -0800
Subject: [PATCH 16/19] Fix formatting (yarn run biome check --apply)

---
 .../featureFlags/unleash/badSignature/init.js |  2 +-
 .../featureFlags/unleash/badSignature/test.ts | 12 +++++--
 .../integrations/featureFlags/unleash/init.js |  2 +-
 .../featureFlags/unleash/integration.ts       | 34 +++++++++++--------
 4 files changed, 31 insertions(+), 19 deletions(-)

diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/badSignature/init.js b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/badSignature/init.js
index 3e9a79894532..dc92fbc296a4 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/badSignature/init.js
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/badSignature/init.js
@@ -7,7 +7,7 @@ window.UnleashClient = class {
 };
 
 window.Sentry = Sentry;
-window.sentryUnleashIntegration = Sentry.unleashIntegration({unleashClientClass: window.UnleashClient});
+window.sentryUnleashIntegration = Sentry.unleashIntegration({ unleashClientClass: window.UnleashClient });
 
 Sentry.init({
   dsn: 'https://public@dsn.ingest.sentry.io/1337',
diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/badSignature/test.ts b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/badSignature/test.ts
index 70c25fa8f560..dacb1c0154a3 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/badSignature/test.ts
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/badSignature/test.ts
@@ -41,9 +41,15 @@ sentryTest('Logs and returns if isEnabled does not match expected signature', as
   // Expected error logs.
   expect(errorLogs).toEqual(
     expect.arrayContaining([
-      expect.stringContaining('[Feature Flags] UnleashClient.isEnabled does not match expected signature. arg0: my-feature (string), result: my-feature (string)'),
-      expect.stringContaining('[Feature Flags] UnleashClient.isEnabled does not match expected signature. arg0: 999 (number), result: 999 (number)'),
-      expect.stringContaining('[Feature Flags] UnleashClient.isEnabled does not match expected signature. arg0: [object Object] (object), result: [object Object] (object)'),
+      expect.stringContaining(
+        '[Feature Flags] UnleashClient.isEnabled does not match expected signature. arg0: my-feature (string), result: my-feature (string)',
+      ),
+      expect.stringContaining(
+        '[Feature Flags] UnleashClient.isEnabled does not match expected signature. arg0: 999 (number), result: 999 (number)',
+      ),
+      expect.stringContaining(
+        '[Feature Flags] UnleashClient.isEnabled does not match expected signature. arg0: [object Object] (object), result: [object Object] (object)',
+      ),
     ]),
   );
 });
diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/init.js b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/init.js
index 2a991bfde3f0..9f1f28730cf7 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/init.js
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/init.js
@@ -41,7 +41,7 @@ window.UnleashClient = class {
 };
 
 window.Sentry = Sentry;
-window.sentryUnleashIntegration = Sentry.unleashIntegration({unleashClientClass: window.UnleashClient});
+window.sentryUnleashIntegration = Sentry.unleashIntegration({ unleashClientClass: window.UnleashClient });
 
 Sentry.init({
   dsn: 'https://public@dsn.ingest.sentry.io/1337',
diff --git a/packages/browser/src/integrations/featureFlags/unleash/integration.ts b/packages/browser/src/integrations/featureFlags/unleash/integration.ts
index 29652a1273d8..e910b6946573 100644
--- a/packages/browser/src/integrations/featureFlags/unleash/integration.ts
+++ b/packages/browser/src/integrations/featureFlags/unleash/integration.ts
@@ -29,20 +29,22 @@ import type { UnleashClient, UnleashClientClass } from './types';
  * Sentry.captureException(new Error('something went wrong'));
  * ```
  */
-export const unleashIntegration = defineIntegration(({unleashClientClass}: {unleashClientClass: UnleashClientClass}) => {
-  return {
-    name: 'Unleash',
+export const unleashIntegration = defineIntegration(
+  ({ unleashClientClass }: { unleashClientClass: UnleashClientClass }) => {
+    return {
+      name: 'Unleash',
 
-    processEvent(event: Event, _hint: EventHint, _client: Client): Event {
-      return copyFlagsFromScopeToEvent(event);
-    },
+      processEvent(event: Event, _hint: EventHint, _client: Client): Event {
+        return copyFlagsFromScopeToEvent(event);
+      },
 
-    setupOnce() {
-      const unleashClientPrototype = unleashClientClass.prototype as UnleashClient;
-      fill(unleashClientPrototype, 'isEnabled', _wrappedIsEnabled);
-    },
-  };
-}) satisfies IntegrationFn;
+      setupOnce() {
+        const unleashClientPrototype = unleashClientClass.prototype as UnleashClient;
+        fill(unleashClientPrototype, 'isEnabled', _wrappedIsEnabled);
+      },
+    };
+  },
+) satisfies IntegrationFn;
 
 /**
  * Wraps the UnleashClient.isEnabled method to capture feature flag evaluations. Its only side effect is writing to Sentry scope.
@@ -53,7 +55,9 @@ export const unleashIntegration = defineIntegration(({unleashClientClass}: {unle
  * @param original - The original method.
  * @returns Wrapped method. Results should match the original.
  */
-function _wrappedIsEnabled(original: (this: UnleashClient, ...args: unknown[]) => unknown): (this: UnleashClient, ...args: unknown[]) => unknown {
+function _wrappedIsEnabled(
+  original: (this: UnleashClient, ...args: unknown[]) => unknown,
+): (this: UnleashClient, ...args: unknown[]) => unknown {
   return function (this: UnleashClient, ...args: unknown[]): unknown {
     const toggleName = args[0];
     const result = original.apply(this, args);
@@ -61,7 +65,9 @@ function _wrappedIsEnabled(original: (this: UnleashClient, ...args: unknown[]) =
     if (typeof toggleName === 'string' && typeof result === 'boolean') {
       insertFlagToScope(toggleName, result);
     } else {
-      logger.error(`[Feature Flags] UnleashClient.isEnabled does not match expected signature. arg0: ${toggleName} (${typeof toggleName}), result: ${result} (${typeof result})`);
+      logger.error(
+        `[Feature Flags] UnleashClient.isEnabled does not match expected signature. arg0: ${toggleName} (${typeof toggleName}), result: ${result} (${typeof result})`,
+      );
     }
     return result;
   };

From bcc0b864f52c7adc76ff3f251e3cb692575ad6f3 Mon Sep 17 00:00:00 2001
From: Andrew Liu <159852527+aliu39@users.noreply.github.com>
Date: Thu, 16 Jan 2025 08:56:20 -0800
Subject: [PATCH 17/19] Only log/test if debug build

---
 .../featureFlags/unleash/badSignature/test.ts | 30 +++++++++++--------
 .../featureFlags/unleash/integration.ts       |  3 +-
 2 files changed, 19 insertions(+), 14 deletions(-)

diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/badSignature/test.ts b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/badSignature/test.ts
index dacb1c0154a3..9b95d4d51c81 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/badSignature/test.ts
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/badSignature/test.ts
@@ -8,6 +8,8 @@ sentryTest('Logs and returns if isEnabled does not match expected signature', as
   if (shouldSkipFeatureFlagsTest()) {
     sentryTest.skip();
   }
+  const bundleKey = process.env.PW_BUNDLE || '';
+  const hasDebug = !bundleKey.includes('_min');
 
   await page.route('https://dsn.ingest.sentry.io/**/*', route => {
     return route.fulfill({
@@ -39,17 +41,19 @@ sentryTest('Logs and returns if isEnabled does not match expected signature', as
   expect(results).toEqual(['my-feature', 999, {}]);
 
   // Expected error logs.
-  expect(errorLogs).toEqual(
-    expect.arrayContaining([
-      expect.stringContaining(
-        '[Feature Flags] UnleashClient.isEnabled does not match expected signature. arg0: my-feature (string), result: my-feature (string)',
-      ),
-      expect.stringContaining(
-        '[Feature Flags] UnleashClient.isEnabled does not match expected signature. arg0: 999 (number), result: 999 (number)',
-      ),
-      expect.stringContaining(
-        '[Feature Flags] UnleashClient.isEnabled does not match expected signature. arg0: [object Object] (object), result: [object Object] (object)',
-      ),
-    ]),
-  );
+  if (hasDebug) {
+    expect(errorLogs).toEqual(
+      expect.arrayContaining([
+        expect.stringContaining(
+          '[Feature Flags] UnleashClient.isEnabled does not match expected signature. arg0: my-feature (string), result: my-feature (string)',
+        ),
+        expect.stringContaining(
+          '[Feature Flags] UnleashClient.isEnabled does not match expected signature. arg0: 999 (number), result: 999 (number)',
+        ),
+        expect.stringContaining(
+          '[Feature Flags] UnleashClient.isEnabled does not match expected signature. arg0: [object Object] (object), result: [object Object] (object)',
+        ),
+      ]),
+    );
+  }
 });
diff --git a/packages/browser/src/integrations/featureFlags/unleash/integration.ts b/packages/browser/src/integrations/featureFlags/unleash/integration.ts
index e910b6946573..9b97f11f9228 100644
--- a/packages/browser/src/integrations/featureFlags/unleash/integration.ts
+++ b/packages/browser/src/integrations/featureFlags/unleash/integration.ts
@@ -1,6 +1,7 @@
 import type { Client, Event, EventHint, IntegrationFn } from '@sentry/core';
 
 import { defineIntegration, fill, logger } from '@sentry/core';
+import { DEBUG_BUILD } from '../../../debug-build';
 import { copyFlagsFromScopeToEvent, insertFlagToScope } from '../../../utils/featureFlags';
 import type { UnleashClient, UnleashClientClass } from './types';
 
@@ -64,7 +65,7 @@ function _wrappedIsEnabled(
 
     if (typeof toggleName === 'string' && typeof result === 'boolean') {
       insertFlagToScope(toggleName, result);
-    } else {
+    } else if (DEBUG_BUILD) {
       logger.error(
         `[Feature Flags] UnleashClient.isEnabled does not match expected signature. arg0: ${toggleName} (${typeof toggleName}), result: ${result} (${typeof result})`,
       );

From c142b4f347f2497c00a04347b906b649ab459961 Mon Sep 17 00:00:00 2001
From: Andrew Liu <159852527+aliu39@users.noreply.github.com>
Date: Thu, 16 Jan 2025 10:36:27 -0800
Subject: [PATCH 18/19] Make UnleashClientClass type more specific

---
 .../src/integrations/featureFlags/unleash/types.ts       | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/packages/browser/src/integrations/featureFlags/unleash/types.ts b/packages/browser/src/integrations/featureFlags/unleash/types.ts
index 8fc3c57843dd..c87798859911 100644
--- a/packages/browser/src/integrations/featureFlags/unleash/types.ts
+++ b/packages/browser/src/integrations/featureFlags/unleash/types.ts
@@ -13,4 +13,11 @@ export interface UnleashClient {
   getVariant(this: UnleashClient, featureName: string): IVariant;
 }
 
-export type UnleashClientClass = new (...args: unknown[]) => UnleashClient;
+export interface IConfig {
+  [key: string]: unknown;
+  appName: string;
+  clientKey: string;
+  url: URL | string;
+}
+
+export type UnleashClientClass = new (config: IConfig) => UnleashClient;

From dcf2595d259a45e00ab39e1a9b0ed14b960a4a2f Mon Sep 17 00:00:00 2001
From: Andrew Liu <159852527+aliu39@users.noreply.github.com>
Date: Tue, 21 Jan 2025 10:08:22 -0800
Subject: [PATCH 19/19] Simplify docstr

---
 .../src/integrations/featureFlags/unleash/integration.ts      | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/packages/browser/src/integrations/featureFlags/unleash/integration.ts b/packages/browser/src/integrations/featureFlags/unleash/integration.ts
index 9b97f11f9228..c451afb831ba 100644
--- a/packages/browser/src/integrations/featureFlags/unleash/integration.ts
+++ b/packages/browser/src/integrations/featureFlags/unleash/integration.ts
@@ -15,11 +15,9 @@ import type { UnleashClient, UnleashClientClass } from './types';
  * import { UnleashClient } from 'unleash-proxy-client';
  * import * as Sentry from '@sentry/browser';
  *
- * const unleashIntegration = Sentry.unleashIntegration({unleashClientClass: UnleashClient});
- *
  * Sentry.init({
  *   dsn: '___PUBLIC_DSN___',
- *   integrations: [unleashIntegration],
+ *   integrations: [Sentry.unleashIntegration({unleashClientClass: UnleashClient})],
  * });
  *
  * const unleash = new UnleashClient(...);