Fix test

src/plugins/discover/public/__mocks__/index_patterns.ts

@@ -10,14 +10,14 @@ import { IndexPatternsService } from '../../../data/common';
 import { indexPatternMock } from './index_pattern';
 
 export const indexPatternsMock = {
-  getCache: () => {
+  getCache: async () => {
     return [indexPatternMock];
   },
-  get: (id: string) => {
+  get: async (id: string) => {
     if (id === 'the-index-pattern-id') {
-      return indexPatternMock;
+      return Promise.resolve(indexPatternMock);
     } else if (id === 'invalid-index-pattern-id') {
-      return Promise.reject(new Error('Invalid index pattern id'));
+      return Promise.reject('Invald');
     }
   },
   updateSavedObject: jest.fn(),

src/plugins/discover/public/application/helpers/use_index_pattern.test.tsx

@@ -8,20 +8,23 @@
 import { useIndexPattern } from './use_index_pattern';
 import { indexPatternMock } from '../../__mocks__/index_pattern';
 import { indexPatternsMock } from '../../__mocks__/index_patterns';
-import { renderHook, act } from '@testing-library/react-hooks';
+import { renderHook } from '@testing-library/react-hooks';
 
 describe('Use Index Pattern', () => {
   test('returning a valid index pattern', async () => {
-    const { result } = renderHook(() => useIndexPattern(indexPatternsMock, 'the-index-pattern-id'));
-    await act(() => Promise.resolve());
+    const { result, waitForNextUpdate } = renderHook(() =>
+      useIndexPattern(indexPatternsMock, 'the-index-pattern-id')
+    );
+    await waitForNextUpdate();
     expect(result.current.indexPattern).toBe(indexPatternMock);
+    expect(result.current.error).toBe(undefined);
   });
 
   test('returning an error', async () => {
-    const { result } = renderHook(() =>
+    const { result, waitForNextUpdate } = renderHook(() =>
       useIndexPattern(indexPatternsMock, 'invalid-index-pattern-id')
     );
-    await act(() => Promise.resolve());
+    await waitForNextUpdate();
     expect(result.current.indexPattern).toBe(undefined);
     expect(result.current.error).toBeTruthy();
   });

src/plugins/discover/public/application/helpers/use_index_pattern.tsx

@@ -15,13 +15,13 @@ export const useIndexPattern = (indexPatterns: IndexPatternsContract, indexPatte
   useEffect(() => {
     async function loadIndexPattern() {
       try {
-        const ip = await indexPatterns.get(indexPatternId);
-        setIndexPattern(ip);
+        const item = await indexPatterns.get(indexPatternId);
+        setIndexPattern(item);
       } catch (e) {
         setError(e);
       }
     }
     loadIndexPattern();
-  });
+  }, [indexPatternId, indexPatterns]);
   return { indexPattern, error };
 };