From 4d4d9e8126917a3b83aa809ff05ecb05177234b2 Mon Sep 17 00:00:00 2001
From: Andrew Liu <159852527+aliu39@users.noreply.github.com>
Date: Wed, 5 Feb 2025 20:37:04 -0800
Subject: [PATCH 1/8] Init src code

---
 .../featureFlags/statsig/index.ts             |  1 +
 .../featureFlags/statsig/integration.ts       | 57 +++++++++++++++++++
 .../featureFlags/statsig/types.ts             | 18 ++++++
 3 files changed, 76 insertions(+)
 create mode 100644 packages/browser/src/integrations/featureFlags/statsig/index.ts
 create mode 100644 packages/browser/src/integrations/featureFlags/statsig/integration.ts
 create mode 100644 packages/browser/src/integrations/featureFlags/statsig/types.ts

diff --git a/packages/browser/src/integrations/featureFlags/statsig/index.ts b/packages/browser/src/integrations/featureFlags/statsig/index.ts
new file mode 100644
index 000000000000..a208e4c7dc0e
--- /dev/null
+++ b/packages/browser/src/integrations/featureFlags/statsig/index.ts
@@ -0,0 +1 @@
+export { statsigIntegration } from './integration';
diff --git a/packages/browser/src/integrations/featureFlags/statsig/integration.ts b/packages/browser/src/integrations/featureFlags/statsig/integration.ts
new file mode 100644
index 000000000000..ac61ae6883c1
--- /dev/null
+++ b/packages/browser/src/integrations/featureFlags/statsig/integration.ts
@@ -0,0 +1,57 @@
+import type { Client, Event, EventHint, IntegrationFn } from '@sentry/core';
+
+import { defineIntegration, logger } from '@sentry/core';
+import { DEBUG_BUILD } from '../../../debug-build';
+import { copyFlagsFromScopeToEvent, insertFlagToScope } from '../../../utils/featureFlags';
+import type { StatsigClient, FeatureGate } from './types';
+
+/**
+ * Sentry integration for capturing feature flag evaluations from the Statsig js-client SDK.
+ *
+ * See the [feature flag documentation](https://develop.sentry.dev/sdk/expected-features/#feature-flags) for more information.
+ *
+ * @example
+ * ```
+ * import { StatsigClient } from '';
+ * import * as Sentry from '@sentry/browser';
+ *
+ * const statsigClient = new StatsigClient();
+ *
+ * Sentry.init({
+ *   dsn: '___PUBLIC_DSN___',
+ *   integrations: [Sentry.statsigIntegration({statsigClient})],
+ * });
+ *
+ * await statsigClient.initializeAsync();  // or statsigClient.initializeSync();
+ *
+ * const result = statsigClient.checkGate('my-feature-gate');
+ * Sentry.captureException(new Error('something went wrong'));
+ * ```
+ */
+export const statsigIntegration = defineIntegration(
+  ({ statsigClient }: { statsigClient: StatsigClient }) => {
+    return {
+      name: 'Statsig',
+
+      processEvent(event: Event, _hint: EventHint, _client: Client): Event {
+        return copyFlagsFromScopeToEvent(event);
+      },
+
+      setupOnce() {
+        statsigClient.on('gate_evaluation', (event: { gate: FeatureGate }) => {
+          try {
+            insertFlagToScope(event.gate.name, event.gate.value);
+          } catch (error) {
+            if (!(error instanceof TypeError)) {
+              throw error;
+            }
+
+            if (DEBUG_BUILD) {
+              logger.error(`[Feature Flags] Error reading Statsig gate evaluation: ${error.message}`);
+            }
+          }
+        });
+      },
+    };
+  },
+) satisfies IntegrationFn;
diff --git a/packages/browser/src/integrations/featureFlags/statsig/types.ts b/packages/browser/src/integrations/featureFlags/statsig/types.ts
new file mode 100644
index 000000000000..2ffe671f818b
--- /dev/null
+++ b/packages/browser/src/integrations/featureFlags/statsig/types.ts
@@ -0,0 +1,18 @@
+export type FeatureGate = {
+  readonly name: string;
+  readonly value: boolean;
+  // readonly ruleID: string;
+  // readonly details: EvaluationDetails;
+  // readonly __evaluation: GateEvaluation | null;
+};
+
+type EventNameToEventDataMap = {
+  gate_evaluation: { gate: FeatureGate };
+};
+
+export interface StatsigClient {
+  on(
+    event: keyof EventNameToEventDataMap,
+    callback: (data: EventNameToEventDataMap[keyof EventNameToEventDataMap]) => void
+  ): void;
+}

From dde56fbdfd67a981bc8fa49c29b527a3a9acee7a Mon Sep 17 00:00:00 2001
From: Andrew Liu <159852527+aliu39@users.noreply.github.com>
Date: Wed, 5 Feb 2025 21:15:31 -0800
Subject: [PATCH 2/8] Add tests and remove type error case

---
 .../featureFlags/statsig/basic/test.ts        | 47 ++++++++++++++
 .../integrations/featureFlags/statsig/init.js | 30 +++++++++
 .../featureFlags/statsig/subject.js           |  3 +
 .../featureFlags/statsig/template.html        |  9 +++
 .../featureFlags/statsig/withScope/test.ts    | 65 +++++++++++++++++++
 packages/browser/src/index.ts                 |  1 +
 .../featureFlags/statsig/integration.ts       | 17 +----
 7 files changed, 158 insertions(+), 14 deletions(-)
 create mode 100644 dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/basic/test.ts
 create mode 100644 dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/init.js
 create mode 100644 dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/subject.js
 create mode 100644 dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/template.html
 create mode 100644 dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/withScope/test.ts

diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/basic/test.ts b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/basic/test.ts
new file mode 100644
index 000000000000..f58db487b111
--- /dev/null
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/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 = (window as any).statsigClient;
+    for (let i = 1; i <= bufferSize; i++) {
+      client.checkGate(`feat${i}`, false);
+    }
+    client.checkGate(`feat${bufferSize + 1}`, true); // eviction
+    client.checkGate('feat3', true); // 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: true });
+  expectedFlags.push({ flag: 'feat3', result: true });
+
+  expect(event.contexts?.flags?.values).toEqual(expectedFlags);
+});
diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/init.js b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/init.js
new file mode 100644
index 000000000000..4a19173e9bb6
--- /dev/null
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/init.js
@@ -0,0 +1,30 @@
+import * as Sentry from '@sentry/browser';
+
+class MockStatsigClient {
+  constructor() {
+    this._gateEvaluationListeners = [];
+  }
+
+  on(event, listener) {
+    this._gateEvaluationListeners.push(listener);
+  }
+
+  checkGate(name, defaultVal) {
+    // Note the actual StatsigClient.checkGate does not take a defaultVal.
+    this._gateEvaluationListeners.forEach(listener => {
+      listener({ gate: { name, value: defaultVal } });
+    });
+    return defaultVal;
+  }
+}
+
+window.statsigClient = new MockStatsigClient();
+
+window.Sentry = Sentry;
+window.sentryStatsigIntegration = Sentry.statsigIntegration({ statsigClient: window.statsigClient });
+
+Sentry.init({
+  dsn: 'https://public@dsn.ingest.sentry.io/1337',
+  sampleRate: 1.0,
+  integrations: [window.sentryStatsigIntegration],
+});
diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/subject.js b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/subject.js
new file mode 100644
index 000000000000..e6697408128c
--- /dev/null
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/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/statsig/template.html b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/template.html
new file mode 100644
index 000000000000..9330c6c679f4
--- /dev/null
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/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/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/withScope/test.ts b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/withScope/test.ts
new file mode 100644
index 000000000000..1131b03ce92b
--- /dev/null
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/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?.isForked === true);
+  const mainReqPromise = waitForErrorRequest(page, event => !!event.tags?.isForked === false);
+
+  await page.evaluate(() => {
+    const Sentry = (window as any).Sentry;
+    const errorButton = document.querySelector('#error') as HTMLButtonElement;
+    const client = (window as any).statsigClient;
+
+    client.checkGate('shared', true);
+
+    Sentry.withScope((scope: Scope) => {
+      client.checkGate('forked', true);
+      client.checkGate('shared', false);
+      scope.setTag('isForked', true);
+      if (errorButton) {
+        errorButton.click();
+      }
+    });
+
+    client.checkGate('main', true);
+    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: 'forked', result: true },
+    { flag: 'shared', result: false },
+  ]);
+
+  expect(mainEvent.contexts?.flags?.values).toEqual([
+    { flag: 'shared', result: true },
+    { flag: 'main', result: true },
+  ]);
+});
diff --git a/packages/browser/src/index.ts b/packages/browser/src/index.ts
index 42c388d73547..2abe7beb55fb 100644
--- a/packages/browser/src/index.ts
+++ b/packages/browser/src/index.ts
@@ -68,3 +68,4 @@ export {
 export { launchDarklyIntegration, buildLaunchDarklyFlagUsedHandler } from './integrations/featureFlags/launchdarkly';
 export { openFeatureIntegration, OpenFeatureIntegrationHook } from './integrations/featureFlags/openfeature';
 export { unleashIntegration } from './integrations/featureFlags/unleash';
+export { statsigIntegration } from './integrations/featureFlags/statsig';
diff --git a/packages/browser/src/integrations/featureFlags/statsig/integration.ts b/packages/browser/src/integrations/featureFlags/statsig/integration.ts
index ac61ae6883c1..f106e2bf32ef 100644
--- a/packages/browser/src/integrations/featureFlags/statsig/integration.ts
+++ b/packages/browser/src/integrations/featureFlags/statsig/integration.ts
@@ -1,7 +1,6 @@
 import type { Client, Event, EventHint, IntegrationFn } from '@sentry/core';
 
-import { defineIntegration, logger } from '@sentry/core';
-import { DEBUG_BUILD } from '../../../debug-build';
+import { defineIntegration } from '@sentry/core';
 import { copyFlagsFromScopeToEvent, insertFlagToScope } from '../../../utils/featureFlags';
 import type { StatsigClient, FeatureGate } from './types';
 
@@ -37,19 +36,9 @@ export const statsigIntegration = defineIntegration(
         return copyFlagsFromScopeToEvent(event);
       },
 
-      setupOnce() {
+      setup() {
         statsigClient.on('gate_evaluation', (event: { gate: FeatureGate }) => {
-          try {
-            insertFlagToScope(event.gate.name, event.gate.value);
-          } catch (error) {
-            if (!(error instanceof TypeError)) {
-              throw error;
-            }
-
-            if (DEBUG_BUILD) {
-              logger.error(`[Feature Flags] Error reading Statsig gate evaluation: ${error.message}`);
-            }
-          }
+          insertFlagToScope(event.gate.name, event.gate.value);
         });
       },
     };

From 694acfe02ce9c3efdfc1110d5714f6520e3ff033 Mon Sep 17 00:00:00 2001
From: Andrew Liu <159852527+aliu39@users.noreply.github.com>
Date: Wed, 5 Feb 2025 21:18:24 -0800
Subject: [PATCH 3/8] Biome check

---
 .../featureFlags/statsig/integration.ts       | 30 +++++++++----------
 .../featureFlags/statsig/types.ts             |  2 +-
 2 files changed, 15 insertions(+), 17 deletions(-)

diff --git a/packages/browser/src/integrations/featureFlags/statsig/integration.ts b/packages/browser/src/integrations/featureFlags/statsig/integration.ts
index f106e2bf32ef..eaa79b09d646 100644
--- a/packages/browser/src/integrations/featureFlags/statsig/integration.ts
+++ b/packages/browser/src/integrations/featureFlags/statsig/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 { StatsigClient, FeatureGate } from './types';
+import type { FeatureGate, StatsigClient } from './types';
 
 /**
  * Sentry integration for capturing feature flag evaluations from the Statsig js-client SDK.
@@ -27,20 +27,18 @@ import type { StatsigClient, FeatureGate } from './types';
  * Sentry.captureException(new Error('something went wrong'));
  * ```
  */
-export const statsigIntegration = defineIntegration(
-  ({ statsigClient }: { statsigClient: StatsigClient }) => {
-    return {
-      name: 'Statsig',
+export const statsigIntegration = defineIntegration(({ statsigClient }: { statsigClient: StatsigClient }) => {
+  return {
+    name: 'Statsig',
 
-      processEvent(event: Event, _hint: EventHint, _client: Client): Event {
-        return copyFlagsFromScopeToEvent(event);
-      },
+    processEvent(event: Event, _hint: EventHint, _client: Client): Event {
+      return copyFlagsFromScopeToEvent(event);
+    },
 
-      setup() {
-        statsigClient.on('gate_evaluation', (event: { gate: FeatureGate }) => {
-          insertFlagToScope(event.gate.name, event.gate.value);
-        });
-      },
-    };
-  },
-) satisfies IntegrationFn;
+    setup() {
+      statsigClient.on('gate_evaluation', (event: { gate: FeatureGate }) => {
+        insertFlagToScope(event.gate.name, event.gate.value);
+      });
+    },
+  };
+}) satisfies IntegrationFn;
diff --git a/packages/browser/src/integrations/featureFlags/statsig/types.ts b/packages/browser/src/integrations/featureFlags/statsig/types.ts
index 2ffe671f818b..397df4457101 100644
--- a/packages/browser/src/integrations/featureFlags/statsig/types.ts
+++ b/packages/browser/src/integrations/featureFlags/statsig/types.ts
@@ -13,6 +13,6 @@ type EventNameToEventDataMap = {
 export interface StatsigClient {
   on(
     event: keyof EventNameToEventDataMap,
-    callback: (data: EventNameToEventDataMap[keyof EventNameToEventDataMap]) => void
+    callback: (data: EventNameToEventDataMap[keyof EventNameToEventDataMap]) => void,
   ): void;
 }

From 300f2d4204903fdd0fdc5a1c4bc967091958f84a Mon Sep 17 00:00:00 2001
From: Andrew Liu <159852527+aliu39@users.noreply.github.com>
Date: Wed, 5 Feb 2025 21:32:22 -0800
Subject: [PATCH 4/8] Rm commented FeatureGate props

---
 .../browser/src/integrations/featureFlags/statsig/types.ts     | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/packages/browser/src/integrations/featureFlags/statsig/types.ts b/packages/browser/src/integrations/featureFlags/statsig/types.ts
index 397df4457101..ff0ea820d31f 100644
--- a/packages/browser/src/integrations/featureFlags/statsig/types.ts
+++ b/packages/browser/src/integrations/featureFlags/statsig/types.ts
@@ -1,9 +1,6 @@
 export type FeatureGate = {
   readonly name: string;
   readonly value: boolean;
-  // readonly ruleID: string;
-  // readonly details: EvaluationDetails;
-  // readonly __evaluation: GateEvaluation | null;
 };
 
 type EventNameToEventDataMap = {

From 9588fec0e880da642249449df09f76033d30afe0 Mon Sep 17 00:00:00 2001
From: Andrew Liu <159852527+aliu39@users.noreply.github.com>
Date: Thu, 6 Feb 2025 13:43:48 -0800
Subject: [PATCH 5/8] review comments 1

---
 .../integrations/featureFlags/constants.ts     |  1 +
 .../featureFlags/featureFlags/basic/test.ts    |  2 +-
 .../featureFlags/launchdarkly/basic/test.ts    |  2 +-
 .../featureFlags/openfeature/basic/test.ts     |  2 +-
 .../featureFlags/openfeature/errorHook/test.ts |  2 +-
 .../featureFlags/statsig/basic/test.ts         | 12 ++++++++----
 .../integrations/featureFlags/statsig/init.js  | 13 +++++++++----
 .../featureFlags/statsig/withScope/test.ts     | 18 +++++++++++-------
 .../featureFlags/unleash/basic/test.ts         |  2 +-
 .../featureFlags/statsig/integration.ts        |  2 +-
 10 files changed, 35 insertions(+), 21 deletions(-)
 create mode 100644 dev-packages/browser-integration-tests/suites/integrations/featureFlags/constants.ts

diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/constants.ts b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/constants.ts
new file mode 100644
index 000000000000..680105d242e5
--- /dev/null
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/constants.ts
@@ -0,0 +1 @@
+export const FLAG_BUFFER_SIZE = 100; // Corresponds to constant in featureFlags.ts, in browser utils.
diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/featureFlags/basic/test.ts b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/featureFlags/basic/test.ts
index ed909b19d1fa..fb0eef09b79e 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/featureFlags/basic/test.ts
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/featureFlags/basic/test.ts
@@ -4,7 +4,7 @@ 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.
+import { FLAG_BUFFER_SIZE } from '../../constants'
 
 sentryTest('Basic test with eviction, update, and no async tasks', async ({ getLocalTestUrl, page }) => {
   if (shouldSkipFeatureFlagsTest()) {
diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/launchdarkly/basic/test.ts b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/launchdarkly/basic/test.ts
index e97cb70761ba..ad610854e5c2 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/launchdarkly/basic/test.ts
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/launchdarkly/basic/test.ts
@@ -4,7 +4,7 @@ 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.
+import { FLAG_BUFFER_SIZE } from '../../constants'
 
 sentryTest('Basic test with eviction, update, and no async tasks', async ({ getLocalTestUrl, page }) => {
   if (shouldSkipFeatureFlagsTest()) {
diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/openfeature/basic/test.ts b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/openfeature/basic/test.ts
index a3de589677ea..cb163c418b44 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/openfeature/basic/test.ts
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/openfeature/basic/test.ts
@@ -4,7 +4,7 @@ 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.
+import { FLAG_BUFFER_SIZE } from '../../constants'
 
 sentryTest('Basic test with eviction, update, and no async tasks', async ({ getLocalTestUrl, page }) => {
   if (shouldSkipFeatureFlagsTest()) {
diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/openfeature/errorHook/test.ts b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/openfeature/errorHook/test.ts
index 719782d0b0ab..e9660faec8ca 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/openfeature/errorHook/test.ts
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/openfeature/errorHook/test.ts
@@ -4,7 +4,7 @@ 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.
+import { FLAG_BUFFER_SIZE } from '../../constants'
 
 sentryTest('Flag evaluation error hook', async ({ getLocalTestUrl, page }) => {
   if (shouldSkipFeatureFlagsTest()) {
diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/basic/test.ts b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/basic/test.ts
index f58db487b111..686636b6e300 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/basic/test.ts
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/basic/test.ts
@@ -4,7 +4,7 @@ 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.
+import { FLAG_BUFFER_SIZE } from '../../constants'
 
 sentryTest('Basic test with eviction, update, and no async tasks', async ({ getLocalTestUrl, page }) => {
   if (shouldSkipFeatureFlagsTest()) {
@@ -25,10 +25,14 @@ sentryTest('Basic test with eviction, update, and no async tasks', async ({ getL
   await page.evaluate(bufferSize => {
     const client = (window as any).statsigClient;
     for (let i = 1; i <= bufferSize; i++) {
-      client.checkGate(`feat${i}`, false);
+      client.checkGate(`feat${i}`); // values default to false
     }
-    client.checkGate(`feat${bufferSize + 1}`, true); // eviction
-    client.checkGate('feat3', true); // update
+
+    client.setMockGateValue(`feat${bufferSize + 1}`, true);
+    client.checkGate(`feat${bufferSize + 1}`); // eviction
+
+    client.setMockGateValue('feat3', true);
+    client.checkGate('feat3'); // update
   }, FLAG_BUFFER_SIZE);
 
   const reqPromise = waitForErrorRequest(page);
diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/init.js b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/init.js
index 4a19173e9bb6..40e1593fc2aa 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/init.js
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/init.js
@@ -3,18 +3,23 @@ import * as Sentry from '@sentry/browser';
 class MockStatsigClient {
   constructor() {
     this._gateEvaluationListeners = [];
+    this._mockGateValues = {};
   }
 
   on(event, listener) {
     this._gateEvaluationListeners.push(listener);
   }
 
-  checkGate(name, defaultVal) {
-    // Note the actual StatsigClient.checkGate does not take a defaultVal.
+  checkGate(name) {
+    const value = this._mockGateValues[name] || false;  // unknown features default to false.
     this._gateEvaluationListeners.forEach(listener => {
-      listener({ gate: { name, value: defaultVal } });
+      listener({ gate: { name, value } });
     });
-    return defaultVal;
+    return value;
+  }
+
+  setMockGateValue(name, value) {
+    this._mockGateValues[name] = value;
   }
 }
 
diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/withScope/test.ts b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/withScope/test.ts
index 1131b03ce92b..cf41767036b6 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/withScope/test.ts
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/withScope/test.ts
@@ -30,18 +30,22 @@ sentryTest('Flag evaluations in forked scopes are stored separately.', async ({
     const errorButton = document.querySelector('#error') as HTMLButtonElement;
     const client = (window as any).statsigClient;
 
-    client.checkGate('shared', true);
+    client.setMockGateValue('shared', true);
+    client.setMockGateValue('main', true);
+
+    client.checkGate('shared');
 
     Sentry.withScope((scope: Scope) => {
-      client.checkGate('forked', true);
-      client.checkGate('shared', false);
+      client.setMockGateValue('forked', true);
+      client.setMockGateValue('shared', false); // override the value in the parent scope.
+
+      client.checkGate('forked');
+      client.checkGate('shared');
       scope.setTag('isForked', true);
-      if (errorButton) {
-        errorButton.click();
-      }
+      errorButton.click();
     });
 
-    client.checkGate('main', true);
+    client.checkGate('main');
     Sentry.getCurrentScope().setTag('isForked', false);
     errorButton.click();
     return true;
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 5bb72caddd24..26793e8851ab 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
@@ -4,7 +4,7 @@ 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.
+import { FLAG_BUFFER_SIZE } from '../../constants'
 
 sentryTest('Basic test with eviction, update, and no async tasks', async ({ getLocalTestUrl, page }) => {
   if (shouldSkipFeatureFlagsTest()) {
diff --git a/packages/browser/src/integrations/featureFlags/statsig/integration.ts b/packages/browser/src/integrations/featureFlags/statsig/integration.ts
index eaa79b09d646..3b2f9be2889c 100644
--- a/packages/browser/src/integrations/featureFlags/statsig/integration.ts
+++ b/packages/browser/src/integrations/featureFlags/statsig/integration.ts
@@ -11,7 +11,7 @@ import type { FeatureGate, StatsigClient } from './types';
  *
  * @example
  * ```
- * import { StatsigClient } from '';
+ * import { StatsigClient } from '@statsig/js-client';
  * import * as Sentry from '@sentry/browser';
  *
  * const statsigClient = new StatsigClient();

From fa773bbe01df7b6203ee73e9827ed51bdfec286b Mon Sep 17 00:00:00 2001
From: Andrew Liu <159852527+aliu39@users.noreply.github.com>
Date: Thu, 6 Feb 2025 13:50:37 -0800
Subject: [PATCH 6/8] Rename client param

---
 .../integrations/featureFlags/statsig/init.js |  2 +-
 .../featureFlags/statsig/integration.ts       | 30 ++++++++++---------
 2 files changed, 17 insertions(+), 15 deletions(-)

diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/init.js b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/init.js
index 40e1593fc2aa..d0125be26cb2 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/init.js
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/init.js
@@ -26,7 +26,7 @@ class MockStatsigClient {
 window.statsigClient = new MockStatsigClient();
 
 window.Sentry = Sentry;
-window.sentryStatsigIntegration = Sentry.statsigIntegration({ statsigClient: window.statsigClient });
+window.sentryStatsigIntegration = Sentry.statsigIntegration({ featureFlagClient: window.statsigClient });
 
 Sentry.init({
   dsn: 'https://public@dsn.ingest.sentry.io/1337',
diff --git a/packages/browser/src/integrations/featureFlags/statsig/integration.ts b/packages/browser/src/integrations/featureFlags/statsig/integration.ts
index 3b2f9be2889c..7870f1250032 100644
--- a/packages/browser/src/integrations/featureFlags/statsig/integration.ts
+++ b/packages/browser/src/integrations/featureFlags/statsig/integration.ts
@@ -18,7 +18,7 @@ import type { FeatureGate, StatsigClient } from './types';
  *
  * Sentry.init({
  *   dsn: '___PUBLIC_DSN___',
- *   integrations: [Sentry.statsigIntegration({statsigClient})],
+ *   integrations: [Sentry.statsigIntegration({featureFlagClient: statsigClient})],
  * });
  *
  * await statsigClient.initializeAsync();  // or statsigClient.initializeSync();
@@ -27,18 +27,20 @@ import type { FeatureGate, StatsigClient } from './types';
  * Sentry.captureException(new Error('something went wrong'));
  * ```
  */
-export const statsigIntegration = defineIntegration(({ statsigClient }: { statsigClient: StatsigClient }) => {
-  return {
-    name: 'Statsig',
+export const statsigIntegration = defineIntegration(
+  ({ featureFlagClient: statsigClient }: { featureFlagClient: StatsigClient }) => {
+    return {
+      name: 'Statsig',
 
-    processEvent(event: Event, _hint: EventHint, _client: Client): Event {
-      return copyFlagsFromScopeToEvent(event);
-    },
+      processEvent(event: Event, _hint: EventHint, _client: Client): Event {
+        return copyFlagsFromScopeToEvent(event);
+      },
 
-    setup() {
-      statsigClient.on('gate_evaluation', (event: { gate: FeatureGate }) => {
-        insertFlagToScope(event.gate.name, event.gate.value);
-      });
-    },
-  };
-}) satisfies IntegrationFn;
+      setup() {
+        statsigClient.on('gate_evaluation', (event: { gate: FeatureGate }) => {
+          insertFlagToScope(event.gate.name, event.gate.value);
+        });
+      },
+    };
+  },
+) satisfies IntegrationFn;

From 0b61d86c280e95dadfa314d94e238e6001cf18b1 Mon Sep 17 00:00:00 2001
From: Andrew Liu <159852527+aliu39@users.noreply.github.com>
Date: Thu, 6 Feb 2025 13:55:17 -0800
Subject: [PATCH 7/8] Test formatting

---
 .../suites/integrations/featureFlags/statsig/basic/test.ts      | 2 +-
 .../suites/integrations/featureFlags/statsig/init.js            | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/basic/test.ts b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/basic/test.ts
index 686636b6e300..5b484b91ba22 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/basic/test.ts
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/basic/test.ts
@@ -4,7 +4,7 @@ import { sentryTest } from '../../../../../utils/fixtures';
 
 import { envelopeRequestParser, shouldSkipFeatureFlagsTest, waitForErrorRequest } from '../../../../../utils/helpers';
 
-import { FLAG_BUFFER_SIZE } from '../../constants'
+import { FLAG_BUFFER_SIZE } from '../../constants';
 
 sentryTest('Basic test with eviction, update, and no async tasks', async ({ getLocalTestUrl, page }) => {
   if (shouldSkipFeatureFlagsTest()) {
diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/init.js b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/init.js
index d0125be26cb2..61d00587f4c6 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/init.js
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/init.js
@@ -11,7 +11,7 @@ class MockStatsigClient {
   }
 
   checkGate(name) {
-    const value = this._mockGateValues[name] || false;  // unknown features default to false.
+    const value = this._mockGateValues[name] || false; // unknown features default to false.
     this._gateEvaluationListeners.forEach(listener => {
       listener({ gate: { name, value } });
     });

From 52da69623525fc8585fd367d652c9e7aa519d6df Mon Sep 17 00:00:00 2001
From: Andrew Liu <159852527+aliu39@users.noreply.github.com>
Date: Thu, 6 Feb 2025 15:19:40 -0800
Subject: [PATCH 8/8] formatting: semicolon after import

---
 .../suites/integrations/featureFlags/featureFlags/basic/test.ts | 2 +-
 .../suites/integrations/featureFlags/launchdarkly/basic/test.ts | 2 +-
 .../suites/integrations/featureFlags/openfeature/basic/test.ts  | 2 +-
 .../integrations/featureFlags/openfeature/errorHook/test.ts     | 2 +-
 .../suites/integrations/featureFlags/unleash/basic/test.ts      | 2 +-
 5 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/featureFlags/basic/test.ts b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/featureFlags/basic/test.ts
index fb0eef09b79e..5cf63a4914ed 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/featureFlags/basic/test.ts
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/featureFlags/basic/test.ts
@@ -4,7 +4,7 @@ import { sentryTest } from '../../../../../utils/fixtures';
 
 import { envelopeRequestParser, shouldSkipFeatureFlagsTest, waitForErrorRequest } from '../../../../../utils/helpers';
 
-import { FLAG_BUFFER_SIZE } from '../../constants'
+import { FLAG_BUFFER_SIZE } from '../../constants';
 
 sentryTest('Basic test with eviction, update, and no async tasks', async ({ getLocalTestUrl, page }) => {
   if (shouldSkipFeatureFlagsTest()) {
diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/launchdarkly/basic/test.ts b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/launchdarkly/basic/test.ts
index ad610854e5c2..d0adafc3d101 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/launchdarkly/basic/test.ts
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/launchdarkly/basic/test.ts
@@ -4,7 +4,7 @@ import { sentryTest } from '../../../../../utils/fixtures';
 
 import { envelopeRequestParser, shouldSkipFeatureFlagsTest, waitForErrorRequest } from '../../../../../utils/helpers';
 
-import { FLAG_BUFFER_SIZE } from '../../constants'
+import { FLAG_BUFFER_SIZE } from '../../constants';
 
 sentryTest('Basic test with eviction, update, and no async tasks', async ({ getLocalTestUrl, page }) => {
   if (shouldSkipFeatureFlagsTest()) {
diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/openfeature/basic/test.ts b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/openfeature/basic/test.ts
index cb163c418b44..21db2c0b7d85 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/openfeature/basic/test.ts
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/openfeature/basic/test.ts
@@ -4,7 +4,7 @@ import { sentryTest } from '../../../../../utils/fixtures';
 
 import { envelopeRequestParser, shouldSkipFeatureFlagsTest, waitForErrorRequest } from '../../../../../utils/helpers';
 
-import { FLAG_BUFFER_SIZE } from '../../constants'
+import { FLAG_BUFFER_SIZE } from '../../constants';
 
 sentryTest('Basic test with eviction, update, and no async tasks', async ({ getLocalTestUrl, page }) => {
   if (shouldSkipFeatureFlagsTest()) {
diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/openfeature/errorHook/test.ts b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/openfeature/errorHook/test.ts
index e9660faec8ca..bae111a5e6f5 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/openfeature/errorHook/test.ts
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/openfeature/errorHook/test.ts
@@ -4,7 +4,7 @@ import { sentryTest } from '../../../../../utils/fixtures';
 
 import { envelopeRequestParser, shouldSkipFeatureFlagsTest, waitForErrorRequest } from '../../../../../utils/helpers';
 
-import { FLAG_BUFFER_SIZE } from '../../constants'
+import { FLAG_BUFFER_SIZE } from '../../constants';
 
 sentryTest('Flag evaluation error hook', async ({ getLocalTestUrl, page }) => {
   if (shouldSkipFeatureFlagsTest()) {
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 26793e8851ab..7e8065dc6172 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
@@ -4,7 +4,7 @@ import { sentryTest } from '../../../../../utils/fixtures';
 
 import { envelopeRequestParser, shouldSkipFeatureFlagsTest, waitForErrorRequest } from '../../../../../utils/helpers';
 
-import { FLAG_BUFFER_SIZE } from '../../constants'
+import { FLAG_BUFFER_SIZE } from '../../constants';
 
 sentryTest('Basic test with eviction, update, and no async tasks', async ({ getLocalTestUrl, page }) => {
   if (shouldSkipFeatureFlagsTest()) {