fix typings

Signed-off-by: Sebastian Malton <sebastian@malton.name>

src/extensions/registries/base-registry.ts

@@ -9,11 +9,12 @@ export class BaseRegistry<T> {
     return this.items.toJS();
   }
 
-  add(items: T[], ext?: LensExtension): () => void; // allow method overloading with required "ext"
+  add(items: T | T[], ext?: LensExtension): () => void; // allow method overloading with required "ext"
   @action
-  add(items: T[]) {
-    this.items.push(...items);
-    return () => this.remove(...items);
+  add(items: T | T[]) {
+    const itemArray: T[] = Array.isArray(items) ? items : [items];
+    this.items.push(...itemArray);
+    return () => this.remove(...itemArray);
   }
 
   @action

src/extensions/registries/page-registry.ts

@@ -62,9 +62,10 @@ export function getExtensionPageUrl<P extends object>({ extensionId, pageId = ""
 
 export class PageRegistry extends BaseRegistry<RegisteredPage> {
   @action
-  add(items: PageRegistration[], ext: LensExtension) {
+  add(items: PageRegistration | PageRegistration[], ext: LensExtension) {
+    const itemArray = Array.isArray(items) ? items : [items];
     try {
-      const pages = items.map(page => ({
+      const pages = itemArray.map(page => ({
         ...page,
         extensionId: ext.name,
         routePath: getExtensionPageUrl({ extensionId: ext.name, pageId: page.id ?? page.routePath }),