Fix usage of IS_SERVER_INITIAL_BUILD in logging + improve doc (#368)

next.config.js

@@ -321,7 +321,18 @@ module.exports = withNextPluginPreval(withBundleAnalyzer(withSourceMaps({
     defaultLoaders,
   }) => {
     if (isServer) {
-      // IS_SERVER_INITIAL_BUILD is meant to be defined only at build time and not at run time, and therefore must not be "made public"
+      /**
+       * This special server-only environment variable isn't string-replaced by webpack during bundling (it isn't added to the DefinePlugin definitions).
+       *
+       * Therefore, it's:
+       * - Always '1' on the server, during development
+       * - Always '1' on the server, during the Next.js build step
+       * - Always undefined on the browser
+       * - Always undefined in API endpoints
+       * - Always undefined during static pages re-generations (ISG) and server-side pages
+       *
+       * It can be useful when performing processing that should only happen during the initial build, or not during the initial build.
+       */
       process.env.IS_SERVER_INITIAL_BUILD = '1';
     }
 

src/modules/core/logging/logger.ts

@@ -19,13 +19,7 @@ export const createLogger = ({ fileLabel }: { fileLabel: string }): SimpleLogger
   return createSimpleLogger({
     prefix: fileLabel,
     shouldPrint: (mode) => {
-      // When bundling with Webpack, only print errors/warnings to avoid printing too much noise on Vercel
-      // IS_SERVER_INITIAL_BUILD is always "1" during development, and is being ignored
-      if (process.env.NEXT_PUBLIC_APP_STAGE !== 'development' && process.env.IS_SERVER_INITIAL_BUILD === '1') {
-        return mode === 'error' || mode === 'warn' || mode === 'debug';
-      }
-
-      // Otherwise, only hide browser errors in production
+      // Only hide browser errors in production
       return !(process.env.NEXT_PUBLIC_APP_STAGE === 'production' && isBrowser());
     },
   });

src/modules/core/networkInformation/networkInformation.ts

@@ -71,7 +71,6 @@ export const getClientNetworkConnectionType = (): ClientNetworkConnectionType =>
   } else {
     return 'not-applicable';
   }
-  console.log('networkInformation', networkInformation);
 
   return networkInformation?.type;
 };

src/pages/api/status.ts

@@ -46,6 +46,7 @@ export const status = async (req: NextApiRequest, res: NextApiResponse): Promise
       GIT_COMMIT_REF: process.env.GIT_COMMIT_REF,
       GIT_COMMIT_TAGS: process.env.GIT_COMMIT_TAGS,
       NEXT_PUBLIC_APP_BASE_URL: process.env.NEXT_PUBLIC_APP_BASE_URL,
+      IS_SERVER_INITIAL_BUILD: process.env.IS_SERVER_INITIAL_BUILD, // Shouldn't be displayed, because should always be undefined in APIs
     });
   } catch (e) {
     Sentry.captureException(e);