Persist configurable connectivity diagnostics

src/shared/connectivityDiagnostics.ts

@@ -25,6 +25,73 @@ export const CONNECTIVITY_SITES = Object.freeze([
 
 export const MAX_CUSTOM_DIAGNOSTIC_SERVICES = 5;
 
+export interface DiagnosticService {
+  id: string;
+  label: string;
+  url: string;
+}
+
+export interface DiagnosticSettings {
+  configured: boolean;
+  customServices: DiagnosticService[];
+  hiddenServiceIds: string[];
+}
+
+function record(value: unknown): Record<string, unknown> {
+  return value && typeof value === 'object' && !Array.isArray(value)
+    ? value as Record<string, unknown>
+    : {};
+}
+
+function diagnosticService(value: unknown): DiagnosticService | null {
+  const candidate = record(value);
+  const id = typeof candidate.id === 'string' ? candidate.id.trim() : '';
+  const label = typeof candidate.label === 'string' ? candidate.label.trim() : '';
+  if (!/^custom-[a-z0-9-]{1,80}$/i.test(id) || !label || label.length > 40) return null;
+  try {
+    const url = new URL(typeof candidate.url === 'string' ? candidate.url.trim() : '');
+    if (
+      url.protocol !== 'https:'
+      || url.username
+      || url.password
+      || (url.port && url.port !== '443')
+    ) return null;
+    return { id, label, url: url.href };
+  } catch {
+    return null;
+  }
+}
+
+export function normalizeDiagnosticSettings(
+  value: unknown,
+  { strict = false }: { strict?: boolean } = {},
+): DiagnosticSettings {
+  const candidate = record(value);
+  const requestedServices = Array.isArray(candidate.customServices) ? candidate.customServices : [];
+  const customServices = requestedServices
+    .map(diagnosticService)
+    .filter((service): service is DiagnosticService => Boolean(service))
+    .filter((service, index, services) => services.findIndex(({ id }) => id === service.id) === index)
+    .slice(0, MAX_CUSTOM_DIAGNOSTIC_SERVICES);
+  const builtInIds = new Set(CONNECTIVITY_SITES.map(({ id }) => id));
+  const requestedHiddenIds = Array.isArray(candidate.hiddenServiceIds) ? candidate.hiddenServiceIds : [];
+  const hiddenServiceIds = requestedHiddenIds
+    .filter((id): id is string => typeof id === 'string' && builtInIds.has(id))
+    .filter((id, index, ids) => ids.indexOf(id) === index);
+  if (strict && (
+    typeof candidate.configured !== 'boolean'
+    || !Array.isArray(candidate.customServices)
+    || !Array.isArray(candidate.hiddenServiceIds)
+    || customServices.length !== requestedServices.length
+    || hiddenServiceIds.length !== requestedHiddenIds.length
+  )) throw new TypeError('Invalid diagnostic settings');
+  return {
+    configured: candidate.configured === true,
+    customServices,
+    hiddenServiceIds,
+  };
+}
+
 export interface ConnectivitySiteResult {
   id: string;
   label: string;