release: WRNexusJS 0.5.10

packages/helpers/src/index.ts

@@ -144,6 +144,7 @@ export {
   currentAppName,
   currentAppOrigin,
   workspaceAppOrigins,
+  workspaceRootDomain,
 } from "./workspace.ts";
 export {
   backoffDelay,

packages/helpers/src/workspace.ts

@@ -56,3 +56,26 @@ export function currentAppOrigin(): string | undefined {
 export function workspaceAppOrigins(): Readonly<Record<string, string>> {
   return Object.freeze({ ...workspaceOrigins() });
 }
+
+/** Shared DNS suffix for configured workspace apps (for example `staging.example.com`). */
+export function workspaceRootDomain(): string {
+  const hosts = Object.values(workspaceOrigins()).map((origin) =>
+    new URL(origin).hostname.toLowerCase(),
+  );
+  if (!hosts.length) {
+    throw new Error("Workspace origins are unavailable.");
+  }
+
+  const labels = hosts.map((host) => host.split(".").reverse());
+  const common: string[] = [];
+  for (let index = 0; index < labels[0]!.length; index++) {
+    const label = labels[0]![index];
+    if (!labels.every((parts) => parts[index] === label)) break;
+    common.push(label!);
+  }
+
+  if (!common.length) {
+    throw new Error(`Workspace apps do not share a root domain: ${hosts.join(", ")}.`);
+  }
+  return common.reverse().join(".");
+}