feat: replace nextjs-config with environment variables (#632)

* chore: remove nextjs-config

* build fix

* update readme

* explicit nextjs env vars + remove feature-unrelated things and obsolete vars from config

* full config removal

* remove force-dynamic from pages

* compile fix

* restore claude-deleted tests

* better .env.example

---------

Co-authored-by: Igor Loskutov <igor.loskutoff@gmail.com>

www/app/lib/apiClient.tsx

@@ -6,10 +6,14 @@ import createFetchClient from "openapi-react-query";
 import { assertExistsAndNonEmptyString } from "./utils";
 import { isBuildPhase } from "./next";
 
-const API_URL = !isBuildPhase
+export const API_URL = !isBuildPhase
   ? assertExistsAndNonEmptyString(process.env.NEXT_PUBLIC_API_URL)
   : "http://localhost";
 
+// TODO decide strict validation or not
+export const WEBSOCKET_URL =
+  process.env.NEXT_PUBLIC_WEBSOCKET_URL || "ws://127.0.0.1:1250";
+
 export const client = createClient<paths>({
   baseUrl: API_URL,
 });

www/app/lib/auth.ts

@@ -1,3 +1,5 @@
+import { assertExistsAndNonEmptyString } from "./utils";
+
 export const REFRESH_ACCESS_TOKEN_ERROR = "RefreshAccessTokenError" as const;
 // 4 min is 1 min less than default authentic value. here we assume that authentic won't be set to access tokens < 4 min
 export const REFRESH_ACCESS_TOKEN_BEFORE = 4 * 60 * 1000;

www/app/lib/edgeConfig.ts

@@ -1,54 +0,0 @@
-import { get } from "@vercel/edge-config";
-import { isBuildPhase } from "./next";
-
-type EdgeConfig = {
-  [domainWithDash: string]: {
-    features: {
-      [featureName in
-        | "requireLogin"
-        | "privacy"
-        | "browse"
-        | "sendToZulip"]: boolean;
-    };
-    auth_callback_url: string;
-    websocket_url: string;
-    api_url: string;
-  };
-};
-
-export type DomainConfig = EdgeConfig["domainWithDash"];
-
-// Edge config main keys can only be alphanumeric and _ or -
-export function edgeKeyToDomain(key: string) {
-  return key.replaceAll("_", ".");
-}
-
-export function edgeDomainToKey(domain: string) {
-  return domain.replaceAll(".", "_");
-}
-
-// get edge config server-side (prefer DomainContext when available), domain is the hostname
-export async function getConfig() {
-  if (process.env.NEXT_PUBLIC_ENV === "development") {
-    try {
-      return require("../../config").localConfig;
-    } catch (e) {
-      // next build() WILL try to execute the require above even if conditionally protected
-      // but thank god it at least runs catch{} block properly
-      if (!isBuildPhase) throw new Error(e);
-      return require("../../config-template").localConfig;
-    }
-  }
-
-  const domain = new URL(process.env.NEXT_PUBLIC_SITE_URL!).hostname;
-  let config = await get(edgeDomainToKey(domain));
-
-  if (typeof config !== "object") {
-    console.warn("No config for this domain, falling back to default");
-    config = await get(edgeDomainToKey("default"));
-  }
-
-  if (typeof config !== "object") throw Error("Error fetching config");
-
-  return config as DomainConfig;
-}

www/app/lib/features.ts

@@ -0,0 +1,55 @@
+export const FEATURES = [
+  "requireLogin",
+  "privacy",
+  "browse",
+  "sendToZulip",
+  "rooms",
+] as const;
+
+export type FeatureName = (typeof FEATURES)[number];
+
+export type Features = Readonly<Record<FeatureName, boolean>>;
+
+export const DEFAULT_FEATURES: Features = {
+  requireLogin: false,
+  privacy: true,
+  browse: false,
+  sendToZulip: false,
+  rooms: false,
+} as const;
+
+function parseBooleanEnv(
+  value: string | undefined,
+  defaultValue: boolean = false,
+): boolean {
+  if (!value) return defaultValue;
+  return value.toLowerCase() === "true";
+}
+
+// WARNING: keep process.env.* as-is, next.js won't see them if you generate dynamically
+const features: Features = {
+  requireLogin: parseBooleanEnv(
+    process.env.NEXT_PUBLIC_FEATURE_REQUIRE_LOGIN,
+    DEFAULT_FEATURES.requireLogin,
+  ),
+  privacy: parseBooleanEnv(
+    process.env.NEXT_PUBLIC_FEATURE_PRIVACY,
+    DEFAULT_FEATURES.privacy,
+  ),
+  browse: parseBooleanEnv(
+    process.env.NEXT_PUBLIC_FEATURE_BROWSE,
+    DEFAULT_FEATURES.browse,
+  ),
+  sendToZulip: parseBooleanEnv(
+    process.env.NEXT_PUBLIC_FEATURE_SEND_TO_ZULIP,
+    DEFAULT_FEATURES.sendToZulip,
+  ),
+  rooms: parseBooleanEnv(
+    process.env.NEXT_PUBLIC_FEATURE_ROOMS,
+    DEFAULT_FEATURES.rooms,
+  ),
+};
+
+export const featureEnabled = (featureName: FeatureName): boolean => {
+  return features[featureName];
+};

www/app/lib/types.ts

@@ -72,3 +72,7 @@ export const assertCustomSession = <S extends Session>(s: S): CustomSession => {
   // no other checks for now
   return r as CustomSession;
 };
+
+export type Mutable<T> = {
+  -readonly [P in keyof T]: T[P];
+};

www/app/lib/utils.ts

@@ -171,5 +171,6 @@ export const assertNotExists = <T>(
 
 export const assertExistsAndNonEmptyString = (
   value: string | null | undefined,
+  err?: string,
 ): NonEmptyString =>
-  parseNonEmptyString(assertExists(value, "Expected non-empty string"));
+  parseNonEmptyString(assertExists(value, err || "Expected non-empty string"));