Assert env vars in demo

apps/demo/src/H5GroveApp.tsx

@@ -1,12 +1,15 @@
-import { App, H5GroveProvider } from '@h5web/app';
+import { App, H5GroveProvider, assertEnvVar } from '@h5web/app';
 import { useLocation } from 'react-router-dom';
 
 import { getFeedbackURL } from './utils';
 
-const URL = import.meta.env.VITE_H5GROVE_URL as string;
-const FILEPATH = import.meta.env.VITE_H5GROVE_FALLBACK_FILEPATH as string;
+const URL = import.meta.env.VITE_H5GROVE_URL;
+const FILEPATH = import.meta.env.VITE_H5GROVE_FALLBACK_FILEPATH;
 
 function H5GroveApp() {
+  assertEnvVar(URL, 'VITE_H5GROVE_URL');
+  assertEnvVar(FILEPATH, 'VITE_H5GROVE_FALLBACK_FILEPATH');
+
   const query = new URLSearchParams(useLocation().search);
   const filepath = query.get('file') || FILEPATH;
 

apps/demo/src/HsdsApp.tsx

@@ -1,15 +1,21 @@
-import { App, HsdsProvider } from '@h5web/app';
+import { App, assertEnvVar, HsdsProvider } from '@h5web/app';
 import { useLocation } from 'react-router-dom';
 
 import { getFeedbackURL } from './utils';
 
-const URL = import.meta.env.VITE_HSDS_URL as string;
-const USERNAME = import.meta.env.VITE_HSDS_USERNAME as string;
-const PASSWORD = import.meta.env.VITE_HSDS_PASSWORD as string;
-const SUBDOMAIN = import.meta.env.VITE_HSDS_SUBDOMAIN as string;
-const FILEPATH = import.meta.env.VITE_HSDS_FALLBACK_FILEPATH as string;
+const URL = import.meta.env.VITE_HSDS_URL;
+const USERNAME = import.meta.env.VITE_HSDS_USERNAME;
+const PASSWORD = import.meta.env.VITE_HSDS_PASSWORD;
+const SUBDOMAIN = import.meta.env.VITE_HSDS_SUBDOMAIN;
+const FILEPATH = import.meta.env.VITE_HSDS_FALLBACK_FILEPATH;
 
 function HsdsApp() {
+  assertEnvVar(URL, 'VITE_HSDS_URL');
+  assertEnvVar(USERNAME, 'VITE_HSDS_USERNAME');
+  assertEnvVar(PASSWORD, 'VITE_HSDS_PASSWORD');
+  assertEnvVar(SUBDOMAIN, 'VITE_HSDS_SUBDOMAIN');
+  assertEnvVar(FILEPATH, 'VITE_HSDS_FALLBACK_FILEPATH');
+
   const query = new URLSearchParams(useLocation().search);
   const filepath = `${SUBDOMAIN}${query.get('file') || FILEPATH}`;
 

packages/app/src/index.ts

@@ -11,6 +11,9 @@ export type { FeedbackContext } from './breadcrumbs/models';
 export { useDataContext } from './providers/DataProvider';
 export type { DataContextValue } from './providers/DataProvider';
 
+// Undocumented
+export { assertEnvVar } from '@h5web/shared';
+
 // Undocumented (for @h5web/h5wasm)
 export { default as DataProvider } from './providers/DataProvider';
 export { DataProviderApi as ProviderApi } from './providers/api';

packages/shared/src/guards.ts

@@ -99,6 +99,16 @@ export function assertStr(
   }
 }
 
+export function assertEnvVar(
+  val: unknown,
+  name: string
+): asserts val is string {
+  assertStr(val, `Expected environment variable ${name} to be defined`);
+  if (val === '') {
+    throw new Error(`Expected environment variable ${name} to not be empty`);
+  }
+}
+
 function assertComplex(val: unknown): asserts val is H5WebComplex {
   if (
     !Array.isArray(val) ||