chore(deps): update dependency node-fetch to v2.6.1 (#4995)

* chore(deps): update dependency node-fetch to v2.6.1

* tests: Use `toString()` method to test Buffer contents

As of `node-fetch@2.4.0`, its internal representation of `body` is now
normalized to a `Buffer` during `Request` construction, and will always be
returned as a `Buffer`, rather than having the `body` being either a String
_or_ a Buffer.  This defeated the way we were testing the `body` but
shouldn't affect the actual `Response`'s `body`.

Ref: node-fetch/node-fetch@7d3293200a91a

Co-authored-by: Renovate Bot <bot@renovateapp.com>
Co-authored-by: Jesse Rosenberger <git@jro.cc>

package.json

@@ -79,7 +79,7 @@
     "@types/micro": "7.3.4",
     "@types/nock": "10.0.3",
     "@types/node": "8.10.65",
-    "@types/node-fetch": "2.5.8",
+    "@types/node-fetch": "2.5.10",
     "@types/qs": "6.9.6",
     "@types/qs-middleware": "1.0.1",
     "@types/request": "2.48.5",
@@ -120,7 +120,7 @@
     "memcached-mock": "0.1.0",
     "mock-req": "0.2.0",
     "nock": "10.0.6",
-    "node-fetch": "2.3.0",
+    "node-fetch": "2.6.1",
     "prettier": "2.1.2",
     "qs-middleware": "1.0.3",
     "request": "2.88.2",

packages/apollo-datasource-rest/src/__tests__/RESTDataSource.test.ts

@@ -260,7 +260,7 @@ describe('RESTDataSource', () => {
 
       expect(fetch).toBeCalledTimes(1);
       expect(fetch.mock.calls[0][0].url).toEqual('https://api.example.com/foo');
-      expect(fetch.mock.calls[0][0].body).toEqual(
+      expect(fetch.mock.calls[0][0].body.toString()).toEqual(
         JSON.stringify({ foo: 'bar' }),
       );
       expect(fetch.mock.calls[0][0].headers.get('Content-Type')).toEqual(
@@ -285,7 +285,7 @@ describe('RESTDataSource', () => {
 
       expect(fetch).toBeCalledTimes(1);
       expect(fetch.mock.calls[0][0].url).toEqual('https://api.example.com/foo');
-      expect(fetch.mock.calls[0][0].body).toEqual(
+      expect(fetch.mock.calls[0][0].body.toString()).toEqual(
         JSON.stringify(['foo', 'bar']),
       );
       expect(fetch.mock.calls[0][0].headers.get('Content-Type')).toEqual(
@@ -321,7 +321,7 @@ describe('RESTDataSource', () => {
 
       expect(fetch).toBeCalledTimes(1);
       expect(fetch.mock.calls[0][0].url).toEqual('https://api.example.com/foo');
-      expect(fetch.mock.calls[0][0].body).toEqual(
+      expect(fetch.mock.calls[0][0].body.toString()).toEqual(
         JSON.stringify({ foo: 'bar' }),
       );
       expect(fetch.mock.calls[0][0].headers.get('Content-Type')).toEqual(
@@ -349,7 +349,7 @@ describe('RESTDataSource', () => {
 
       expect(fetch).toBeCalledTimes(1);
       expect(fetch.mock.calls[0][0].url).toEqual('https://api.example.com/foo');
-      expect(fetch.mock.calls[0][0].body).not.toEqual('{}');
+      expect(fetch.mock.calls[0][0].body.toString()).not.toEqual('{}');
       expect(fetch.mock.calls[0][0].headers.get('Content-Type')).not.toEqual(
         'application/json',
       );