fix: replace __DEV__ with process.env.NODE_ENV for environment checks

Refactor the build process to remove the custom `__DEV__` global declaration and replace it with a more standard `process.env.NODE_ENV !== 'production'` pattern. Adjusted rollup configuration accordingly.

Author: usefulthink

rollup.config.js

@@ -67,15 +67,7 @@ export default [
   // ESM build
   {
     input: "src/index.ts",
-    plugins: [
-      ...basePlugins,
-      replace({
-        preventAssignment: true,
-        values: {
-          __DEV__: 'process.env.NODE_ENV !== "production"',
-        },
-      }),
-    ],
+    plugins: [...basePlugins],
     output: {
       file: "dist/index.js",
       format: "esm",

src/index.ts

@@ -59,8 +59,9 @@ interface APILibraryMap {
 
 type APILibraryName = keyof APILibraryMap;
 
-// The __DEV__ global variable is set by rollup during the build process.
-declare const __DEV__: boolean;
+// Development mode check - bundlers will replace process.env.NODE_ENV at build time
+declare const process: { env: { NODE_ENV?: string } };
+const __DEV__ = process.env.NODE_ENV !== 'production';
 
 let setOptionsWasCalled_ = false;
 

src/messages.ts

@@ -44,8 +44,9 @@ export const MSG_SCRIPT_ELEMENT_EXISTS =
   "problems using the API. Make sure to remove the script " +
   "loading the API.";
 
-// The __DEV__ global variable is set by rollup during the build process.
-declare const __DEV__: boolean;
+// Development mode check - bundlers will replace process.env.NODE_ENV at build time
+declare const process: { env: { NODE_ENV?: string } };
+const __DEV__ = process.env.NODE_ENV !== 'production';
 
 export const logError = (message: string) => {
   console.error(`[@googlemaps/js-api-loader] ${message}`);