address review comments

Signed-off-by: Fredrik Adelöw <freben@gmail.com>

packages/catalog-client/src/types/api.ts

@@ -546,7 +546,7 @@ export interface CatalogApi {
    *
    * The output list of entities is of the same size and in the same order as
    * the requested list of entity refs. Entries that are not found are returned
-   * as null.
+   * as undefined.
    *
    * @param request - Request parameters
    * @param options - Additional options

packages/catalog-client/src/types/discovery.ts

@@ -15,7 +15,9 @@
  */
 
 /**
- * This is a polymorphic version of `DiscoveryApi` / `DiscoveryService`.
+ * This is a structurally similar version of `DiscoveryApi` /
+ * `DiscoveryService`, used here to avoid dependencies on the frontend or
+ * backend plugin API packages and allowing both of those forms to be passed in.
  */
 export type DiscoveryApi = {
   getBaseUrl(pluginId: string): Promise<string>;

packages/catalog-client/src/types/fetch.ts

@@ -15,7 +15,9 @@
  */
 
 /**
- * This is a polymorphic version of `FetchApi`.
+ * This is a structurally similar version of `FetchApi`, used here to avoid
+ * dependencies on the frontend or backend plugin API packages and allowing both
+ * of those forms to be passed in.
  */
 export type FetchApi = {
   fetch: typeof fetch;