add client to the mutation result

Changelog.md

@@ -12,6 +12,8 @@
   [@hwillson](https://github.com/hwillson) in [#3422](https://github.com/apollographql/react-apollo/pull/3422)
 - Fixed problematic re-renders that were caused by using `fetchMore.updateQuery` with `notifyOnNetworkStatusChange` set to true. When `notifyOnNetworkStatusChange` is true, re-renders will now wait until `updateQuery` has completed, to make sure the updated data is used during the render. <br/>
   [@hwillson](https://github.com/hwillson) in [#3433](https://github.com/apollographql/react-apollo/pull/3433)
+- Add `client` to the `useMutation` result. <br/>
+  [@joshalling](https://github.com/joshalling) in [#3417](https://github.com/apollographql/react-apollo/pull/3417)
 - Documentation fixes. <br/>
   [@SeanRoberts](https://github.com/SeanRoberts) in [#3380](https://github.com/apollographql/react-apollo/pull/3380)
 

packages/hooks/src/__tests__/useMutation.test.tsx

@@ -2,7 +2,7 @@ import React, { useEffect } from 'react';
 import { DocumentNode } from 'graphql';
 import gql from 'graphql-tag';
 import { MockedProvider, mockSingleLink } from '@apollo/react-testing';
-import { render, cleanup } from '@testing-library/react';
+import { render, cleanup, wait } from '@testing-library/react';
 import { ApolloProvider, useMutation } from '@apollo/react-hooks';
 import { ApolloClient } from 'apollo-client';
 import { InMemoryCache } from 'apollo-cache-inmemory';
@@ -236,6 +236,23 @@ describe('useMutation Hook', () => {
         </MockedProvider>
       );
     });
+
+    it('should return the current client instance in the result object', async () => {
+      const Component = () => {
+        const [, { client }] = useMutation(CREATE_TODO_MUTATION);
+        expect(client).toBeDefined();
+        expect(client instanceof ApolloClient).toBeTruthy();
+        return null;
+      };
+
+      render(
+        <MockedProvider>
+          <Component />
+        </MockedProvider>
+      );
+
+      await wait();
+    });
   });
 
   describe('Optimistic response', () => {

packages/hooks/src/data/MutationData.ts

@@ -42,6 +42,7 @@ export class MutationData<
   public execute(result: MutationResult<TData>) {
     this.isMounted = true;
     this.verifyDocumentType(this.getOptions().mutation, DocumentType.Mutation);
+    result.client = this.refreshClient().client;
     return [this.runMutation, result] as MutationTuple<TData, TVariables>;
   }