webpack polyfill

Author: leoromanovsky

packages/core/src/tools/getGlobalObject.ts

@@ -6,39 +6,26 @@ export function getGlobalObject<T = typeof globalThis>(): T {
   if (typeof globalThis === 'object') {
     return globalThis as unknown as T
   }
-
-  // Polyfill globalThis if it doesn't exist
-  if (typeof globalThis === 'undefined') {
-    Object.defineProperty(Object.prototype, '_dd_temp_', {
-      get() {
-        return this as object
-      },
-      configurable: true,
-    })
-    // @ts-ignore _dd_temp is defined using defineProperty
-    let globalObject: unknown = _dd_temp_
-    // @ts-ignore _dd_temp is defined using defineProperty
-    delete Object.prototype._dd_temp_
-    if (typeof globalObject !== 'object') {
-      // on safari _dd_temp_ is available on window but not globally
-      // fallback on other browser globals check
-      if (typeof self === 'object') {
-        globalObject = self
-      } else if (typeof window === 'object') {
-        globalObject = window
-      } else {
-        globalObject = {}
-      }
+  Object.defineProperty(Object.prototype, '_dd_temp_', {
+    get() {
+      return this as object
+    },
+    configurable: true,
+  })
+  // @ts-ignore _dd_temp is defined using defineProperty
+  let globalObject: unknown = _dd_temp_
+  // @ts-ignore _dd_temp is defined using defineProperty
+  delete Object.prototype._dd_temp_
+  if (typeof globalObject !== 'object') {
+    // on safari _dd_temp_ is available on window but not globally
+    // fallback on other browser globals check
+    if (typeof self === 'object') {
+      globalObject = self
+    } else if (typeof window === 'object') {
+      globalObject = window
+    } else {
+      globalObject = {}
     }
-
-    // Define globalThis if it doesn't exist
-    Object.defineProperty(globalObject as object, 'globalThis', {
-      value: globalObject,
-      writable: true,
-      enumerable: false,
-      configurable: true,
-    })
   }
-
-  return globalThis as unknown as T
+  return globalObject as T
 }

packages/flagging/src/entries/main.ts

@@ -1,11 +1,5 @@
 import { defineGlobal, getGlobalObject } from '@datadog/browser-core'
-
-// Apply globalThis polyfill before importing OpenFeature
-// The OpenFeature web SDK uses globalThis which is not available in older browsers (like Chrome 63).
-// Our getGlobalObject() utility provides a polyfill that makes globalThis available by using
-// fallbacks like window or self. We need to call it before importing OpenFeature to ensure
-// the polyfill is in place when OpenFeature tries to use globalThis.
-getGlobalObject()
+import './polyfill'
 
 import { DatadogProvider } from '../openfeature/provider'
 

packages/flagging/src/entries/polyfill.ts

@@ -0,0 +1,36 @@
+/**
+ * Polyfill for globalThis that runs before any other code
+ * Based on https://mathiasbynens.be/notes/globalthis
+ */
+
+if (typeof globalThis === 'undefined') {
+  Object.defineProperty(Object.prototype, '_dd_temp_', {
+    get() {
+      return this as object
+    },
+    configurable: true,
+  })
+  // @ts-ignore _dd_temp is defined using defineProperty
+  let globalObject: unknown = _dd_temp_
+  // @ts-ignore _dd_temp is defined using defineProperty
+  delete Object.prototype._dd_temp_
+  if (typeof globalObject !== 'object') {
+    // on safari _dd_temp_ is available on window but not globally
+    // fallback on other browser globals check
+    if (typeof self === 'object') {
+      globalObject = self
+    } else if (typeof window === 'object') {
+      globalObject = window
+    } else {
+      globalObject = {}
+    }
+  }
+
+  // Define globalThis if it doesn't exist
+  Object.defineProperty(globalObject as object, 'globalThis', {
+    value: globalObject,
+    writable: true,
+    enumerable: false,
+    configurable: true,
+  })
+}

packages/flagging/webpack.config.js

@@ -5,6 +5,10 @@ const webpackBase = require('../../webpack.base')
 module.exports = (_env, argv) =>
   webpackBase({
     mode: argv.mode,
-    entry: path.resolve(__dirname, 'src/entries/main.ts'),
+    // Use polyfill.ts as the entry point to ensure globalThis is defined before any other code runs.
+    // This is necessary because @openfeature/web-sdk uses globalThis which is not available in older
+    // browsers (like Chrome 63). The polyfill must run before any other code to prevent
+    // "globalThis is not defined" errors.
+    entry: path.resolve(__dirname, 'src/entries/polyfill.ts'),
     filename: 'datadog-flagging.js',
   })