delete dead code/comments & add useRequest docstring

awx/ui_next/src/screens/Inventory/Inventory.jsx

@@ -37,8 +37,6 @@ function Inventory({ i18n, setBreadcrumb }) {
   useEffect(() => {
     async function fetchData() {
       try {
-        // TODO: delete next line
-        // setHasContentLoading(true);
         const { data } = await InventoriesAPI.readDetail(match.params.id);
         setBreadcrumb(data);
         setInventory(data);

awx/ui_next/src/screens/Inventory/InventoryDetail/InventoryDetail.jsx

@@ -31,8 +31,8 @@ function InventoryDetail({ inventory, i18n }) {
   );
 
   useEffect(() => {
-    fetchInstanceGroups(inventory.id);
-  }, [fetchInstanceGroups, inventory.id]);
+    fetchInstanceGroups();
+  }, [fetchInstanceGroups]);
 
   const deleteInventory = async () => {
     await InventoriesAPI.destroy(inventory.id);

awx/ui_next/src/util/useRequest.js

@@ -1,5 +1,16 @@
 import { useEffect, useState, useRef, useCallback } from 'react';
 
+/*
+ * The useRequest hook accepts a request function and returns an object with
+ * four values:
+ *   request: a function to call to invoke the request
+ *   result: the value returned from the request function (once invoked)
+ *   isLoading: boolean state indicating whether the request is in active/in flight
+ *   error: any caught error resulting from the request
+ *
+ * The hook also accepts an optional second parameter which is a default
+ * value to set as result before the first time the request is made.
+ */
 export default function useRequest(makeRequest, initialValue) {
   const [result, setResult] = useState(initialValue);
   const [error, setError] = useState(null);