fix: search categories

packages/arcgis-rest-portal/src/items/search.ts

@@ -22,5 +22,20 @@ import { genericSearch } from "../util/generic-search.js";
 export function searchItems(
   search: string | ISearchOptions | SearchQueryBuilder
 ): Promise<ISearchResult<IItem>> {
+  // For the "categories" param, we want to send each entry in the array as
+  // a distinct parameter. I.e. categories: ["a", "b,c"] should be sent as
+  // ....&categories=a&categories=b,c
+  // To get this behavior out of our lower-level request modules, we need to
+  // send category as an array of arrays.
+  if (
+    typeof search === "object" &&
+    !(search instanceof SearchQueryBuilder) &&
+    search.params?.categories
+  ) {
+    search.params.categories = search.params.categories.map((x) => {
+      return x.split(",");
+    });
+  }
+
   return genericSearch<IItem>(search, "item");
 }

packages/arcgis-rest-portal/test/items/search.test.ts

@@ -142,7 +142,7 @@ describe("search", () => {
         expect(fetchMock.called()).toEqual(true);
         const [url, options] = fetchMock.lastCall("*");
         expect(url).toEqual(
-          "https://www.arcgis.com/sharing/rest/search?f=json&q=Washington&categories=%2FCategories%2FWater%2C%2FCategories%2FForest"
+          "https://www.arcgis.com/sharing/rest/search?f=json&q=Washington&categories=%2FCategories%2FWater&categories=%2FCategories%2FForest"
         );
         expect(options.method).toBe("GET");
         done();