fix throw error in mutation

src/createApolloMockedProvider.tsx

@@ -37,6 +37,9 @@ export const createApolloMockedProvider = (
   const client = new ApolloClient({
     link: ApolloLink.from([onError(() => {}), new SchemaLink({ schema })]),
     cache: cache || globalCache || new InMemoryCache(),
+    defaultOptions: {
+      mutate: { errorPolicy: 'all' },
+    },
   });
 
   const Provider = provider ? provider : ApolloProvider;

test/createApolloMockedProvider.test.tsx

@@ -1,7 +1,12 @@
 import React from 'react';
 import { createApolloMockedProvider } from '../src';
 import { readFileSync } from 'fs';
-import { render, wait, waitForDomChange } from '@testing-library/react';
+import {
+  render,
+  wait,
+  waitForDomChange,
+  fireEvent,
+} from '@testing-library/react';
 import {
   GET_TODO_QUERY,
   GET_TODOS_QUERY,
@@ -59,7 +64,7 @@ test('works with custom resolvers', async () => {
   expect(getByText('Second Todo')).toBeTruthy();
 });
 
-test('allows throwing errors within resolvers to mock API errors', async () => {
+test('allows throwing errors within resolvers to mock Query API errors', async () => {
   const MockedProvider = createApolloMockedProvider(typeDefs);
   const { container } = render(
     <MockedProvider
@@ -100,6 +105,38 @@ test('allows throwing errors within resolvers to mock API errors', async () => {
   expect(container.textContent).toMatch(/GraphQL error: Boom/);
 });
 
+test('allows throwing errors within resolvers to mock Mutation API errors', async () => {
+  const MockedProvider = createApolloMockedProvider(typeDefs);
+  const { container, getByText } = render(
+    <MockedProvider
+      customResolvers={{
+        Query: () => ({
+          todos: () => [
+            {
+              text: 'First Todo',
+            },
+            {
+              text: 'Second Todo',
+            },
+          ],
+        }),
+        Mutation: () => ({
+          addTodo: () => {
+            throw new Error('Boom');
+          },
+        }),
+      }}
+    >
+      <Todo />
+    </MockedProvider>
+  );
+
+  await waitForDomChange();
+  fireEvent.click(getByText('Add todo'));
+  await waitForDomChange();
+  expect(container.textContent).toMatch(/GraphQL error: Boom/);
+});
+
 describe('caching', () => {
   test('allows users to provide a global cache', async () => {
     const cache = new InMemoryCache();

test/fixtures/Todo.tsx

@@ -70,6 +70,7 @@ export const Todo = () => (
                   )}
                   <button
                     onClick={() => {
+                      console.log('add');
                       addTodo({ variables: { input: { text: 'hardcoded' } } });
                     }}
                   >