feat(resources): new method to add a new resource to an item

AFFECTS PACKAGES:
@esri/arcgis-rest-items

ISSUES CLOSED: #281

packages/arcgis-rest-items/src/add.ts

@@ -73,3 +73,27 @@ export function addItemData(
 
   return request(url, requestOptions);
 }
+
+/**
+ * Add a resource associated with an item
+ *
+ * @param requestOptions - Options for the request
+ * @returns A Promise to add item resources.
+ */
+export function addItemResource(
+  requestOptions: IItemResourceAddRequestOptions
+): Promise<IItemResourceResponse> {
+  const owner = determineOwner(requestOptions);
+  const url = `${getPortalUrl(requestOptions)}/content/users/${owner}/items/${
+    requestOptions.id
+  }/addResources`;
+
+  requestOptions.params = {
+    file: requestOptions.resource,
+    fileName: requestOptions.name,
+    text: requestOptions.content,
+    ...requestOptions.params
+  };
+
+  return request(url, requestOptions);
+}

packages/arcgis-rest-items/test/add.test.ts

@@ -2,7 +2,7 @@ import * as fetchMock from "fetch-mock";
 
 import { attachmentFile } from "../../arcgis-rest-feature-service/test/attachments.test";
 
-import { addItemJsonData, addItemData } from "../src/add";
+import { addItemJsonData, addItemData, addItemResource } from "../src/add";
 
 import { ItemSuccessResponse } from "./mocks/item";
 
@@ -172,5 +172,42 @@ describe("search", () => {
           fail(e);
         });
     });
+
+    it("should add a binary resource to an item", done => {
+      fetchMock.once("*", {
+        success: true
+      });
+
+      const file = attachmentFile();
+
+      addItemResource({
+        id: "3ef",
+        // File() is only available in the browser
+        resource: file,
+        name: "thebigkahuna",
+        ...MOCK_USER_REQOPTS
+      })
+        .then(() => {
+          expect(fetchMock.called()).toEqual(true);
+          const [url, options]: [string, RequestInit] = fetchMock.lastCall("*");
+          expect(url).toEqual(
+            "https://myorg.maps.arcgis.com/sharing/rest/content/users/casey/items/3ef/addResources"
+          );
+          expect(options.method).toBe("POST");
+          expect(options.body instanceof FormData).toBeTruthy();
+          const params = options.body as FormData;
+          if (params.get) {
+            expect(params.get("token")).toEqual("fake-token");
+            expect(params.get("f")).toEqual("json");
+            expect(params.get("file")).toEqual(file);
+            expect(params.get("fileName")).toEqual("thebigkahuna");
+          }
+
+          done();
+        })
+        .catch(e => {
+          fail(e);
+        });
+    });
   }); // auth requests
 });