feat: Support make-fetch-happen fetcher when communicating with services

gateway-js/CHANGELOG.md

@@ -4,7 +4,7 @@
 
 > The changes noted within this `vNEXT` section have not been released yet.  New PRs and commits which introduce changes should include an entry in this `vNEXT` section as part of their development.  When a release is being prepared, a new header will be (manually) created below and the appropriate changes within that release will be moved into the new section.
 
-- _Nothing yet! Stay tuned!_
+- When using a custom `fetcher` on a `RemoteGraphQLDataSource`, use that fetcher's `Request` initialization in order to satisfy and of its own implementation details.  This is necessary, for example, when using `make-fetch-happen`. [PR #188](https://github.com/apollographql/federation/pull/188) [Issue #191](https://github.com/apollographql/federation/issues/191)
 
 ## v0.20.4
 

gateway-js/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@apollo/gateway",
-  "version": "0.20.4",
+  "version": "0.21.0",
   "description": "Apollo Gateway",
   "author": "Apollo <[email protected]>",
   "main": "dist/index.js",

gateway-js/src/__mocks__/make-fetch-happen-fetcher.ts

@@ -0,0 +1,51 @@
+/// <reference types="jest" />
+
+import {
+  fetch,
+  Response,
+  BodyInit,
+  Headers,
+  HeadersInit
+} from 'apollo-server-env';
+
+import fetcher from 'make-fetch-happen';
+
+interface MakeFetchHappenMock extends jest.Mock<typeof fetch> {
+  mockResponseOnce(data?: any, headers?: HeadersInit, status?: number): this;
+  mockJSONResponseOnce(data?: object, headers?: HeadersInit): this;
+}
+
+const mockMakeFetchHappen = jest.fn<typeof fetch>(fetcher) as MakeFetchHappenMock;
+
+mockMakeFetchHappen.mockResponseOnce = (
+  data?: BodyInit,
+  headers?: Headers,
+  status: number = 200,
+) => {
+  return mockMakeFetchHappen.mockImplementationOnce(async () => {
+    return new Response(data, {
+      status,
+      headers,
+    });
+  });
+};
+
+mockMakeFetchHappen.mockJSONResponseOnce = (
+  data = {},
+  headers?: Headers,
+  status?: number,
+) => {
+  return mockMakeFetchHappen.mockResponseOnce(
+    JSON.stringify(data),
+    Object.assign({ 'Content-Type': 'application/json' }, headers),
+    status,
+  );
+};
+
+const makeFetchMock = {
+  makeFetchHappenFetcher: mockMakeFetchHappen,
+};
+
+jest.doMock('make-fetch-happen', () => makeFetchMock);
+
+export = makeFetchMock;

gateway-js/src/__tests__/gateway/buildService.test.ts

@@ -77,8 +77,7 @@ it('correctly passes the context from ApolloServer to datasources', async () =>
   });
 
   expect(fetch).toBeCalledTimes(1);
-  expect(fetch).toHaveFetched({
-    url: 'https://api.example.com/foo',
+  expect(fetch).toHaveFetched('https://api.example.com/foo', {
     body: {
       query: `{me{username}}`,
       variables: {},
@@ -125,8 +124,7 @@ it('makes enhanced introspection request using datasource', async () => {
 
   expect(fetch).toBeCalledTimes(1);
 
-  expect(fetch).toHaveFetched({
-    url: 'https://api.example.com/override',
+  expect(fetch).toHaveFetched('https://api.example.com/override', {
     body: {
       query: SERVICE_DEFINITION_QUERY,
     },
@@ -171,8 +169,7 @@ it('customizes request on a per-service basis', async () => {
 
   expect(fetch).toBeCalledTimes(3);
 
-  expect(fetch).toHaveFetched({
-    url: 'https://api.example.com/one',
+  expect(fetch).toHaveFetched('https://api.example.com/one', {
     body: {
       query: `query __ApolloGetServiceDefinition__ { _service { sdl } }`,
     },
@@ -181,8 +178,7 @@ it('customizes request on a per-service basis', async () => {
     },
   });
 
-  expect(fetch).toHaveFetched({
-    url: 'https://api.example.com/two',
+  expect(fetch).toHaveFetched('https://api.example.com/two', {
     body: {
       query: `query __ApolloGetServiceDefinition__ { _service { sdl } }`,
     },
@@ -191,8 +187,7 @@ it('customizes request on a per-service basis', async () => {
     },
   });
 
-  expect(fetch).toHaveFetched({
-    url: 'https://api.example.com/three',
+  expect(fetch).toHaveFetched('https://api.example.com/three', {
     body: {
       query: `query __ApolloGetServiceDefinition__ { _service { sdl } }`,
     },

gateway-js/src/__tests__/matchers/toHaveFetched.ts

@@ -1,4 +1,4 @@
-import { Request, RequestInit, Headers } from 'apollo-server-env';
+import { RequestInit, Headers } from 'apollo-server-env';
 
 // Make this file a module
 // See: https://github.com/microsoft/TypeScript/issues/17736
@@ -11,36 +11,39 @@ declare global {
   }
 }
 
-type ExtendedRequest = RequestInit & { url: string };
-
-function prepareHttpRequest(request: ExtendedRequest): Request {
+function prepareHttpOptions(requestUrl: string, requestOpts: RequestInit): RequestInit {
   const headers = new Headers();
   headers.set('Content-Type', 'application/json');
-  if (request.headers) {
-    for (let name in request.headers) {
-      headers.set(name, request.headers[name]);
+  if (requestOpts.headers) {
+    for (let name in requestOpts.headers) {
+      headers.set(name, requestOpts.headers[name]);
     }
   }
 
-  const options: RequestInit = {
+  const requestHttp = {
     method: 'POST',
     headers,
-    body: JSON.stringify(request.body),
+    url: requestUrl
+  };
+
+  return {
+    ...requestHttp,
+    body: JSON.stringify(requestOpts.body)
   };
 
-  return new Request(request.url, options);
 }
 
 function toHaveFetched(
   this: jest.MatcherUtils,
   fetch: jest.SpyInstance,
-  request: ExtendedRequest,
+  requestUrl: string,
+  requestOpts: RequestInit
 ): { message(): string; pass: boolean } {
-  const httpRequest = prepareHttpRequest(request);
+  const httpOptions = prepareHttpOptions(requestUrl, requestOpts);
   let pass = false;
   let message = () => '';
   try {
-    expect(fetch).toBeCalledWith(httpRequest);
+    expect(fetch).toBeCalledWith(requestUrl, httpOptions);
     pass = true;
   } catch (e) {
     message = () => e.message;
@@ -56,13 +59,14 @@ function toHaveFetchedNth(
   this: jest.MatcherUtils,
   fetch: jest.SpyInstance,
   nthCall: number,
-  request: ExtendedRequest,
+  requestUrl: string,
+  requestOpts: RequestInit
 ): { message(): string; pass: boolean } {
-  const httpRequest = prepareHttpRequest(request);
+  const httpOptions = prepareHttpOptions(requestUrl, requestOpts);
   let pass = false;
   let message = () => '';
   try {
-    expect(fetch).toHaveBeenNthCalledWith(nthCall, httpRequest);
+    expect(fetch).toHaveBeenNthCalledWith(nthCall, requestUrl, httpOptions);
     pass = true;
   } catch (e) {
     message = () => e.message;

gateway-js/src/datasources/RemoteGraphQLDataSource.ts

@@ -149,7 +149,12 @@ export class RemoteGraphQLDataSource<TContext extends Record<string, any> = Reco
 
     try {
       // Use our local `fetcher` to allow for fetch injection
-      fetchResponse = await this.fetcher(fetchRequest);
+      // Adding support for custom fetcher such as 'make-fetch-happen' other than default (node fetch);
+      // for it, we need the Request to be constructed by the fetcher's own Request class
+      fetchResponse = await this.fetcher(http.url, {
+        ...http,
+        body: JSON.stringify(requestWithoutHttp)
+      });
 
       if (!fetchResponse.ok) {
         throw await this.errorFromResponse(fetchResponse);

gateway-js/src/datasources/__tests__/RemoteGraphQLDataSource.test.ts

@@ -1,4 +1,5 @@
 import { fetch } from '__mocks__/apollo-server-env';
+import { makeFetchHappenFetcher} from '__mocks__/make-fetch-happen-fetcher';
 
 import {
   ApolloError,
@@ -31,9 +32,8 @@ describe('constructing requests', () => {
 
       expect(data).toEqual({ me: 'james' });
       expect(fetch).toBeCalledTimes(1);
-      expect(fetch).toHaveFetched({
-        url: 'https://api.example.com/foo',
-        body: { query: '{ me { name } }' },
+      expect(fetch).toHaveFetched('https://api.example.com/foo', {
+        body: { query: '{ me { name } }' }
       });
     });
 
@@ -55,8 +55,7 @@ describe('constructing requests', () => {
 
       expect(data).toEqual({ me: 'james' });
       expect(fetch).toBeCalledTimes(1);
-      expect(fetch).toHaveFetched({
-        url: 'https://api.example.com/foo',
+      expect(fetch).toHaveFetched('https://api.example.com/foo', {
         body: { query: '{ me { name } }', variables: { id: '1' } },
       });
     });
@@ -101,8 +100,7 @@ describe('constructing requests', () => {
 
         expect(data).toEqual({ me: 'james' });
         expect(fetch).toBeCalledTimes(2);
-        expect(fetch).toHaveFetchedNth(1, {
-          url: 'https://api.example.com/foo',
+        expect(fetch).toHaveFetchedNth(1, 'https://api.example.com/foo', {
           body: {
             extensions: {
               persistedQuery: {
@@ -112,8 +110,7 @@ describe('constructing requests', () => {
             }
           },
         });
-        expect(fetch).toHaveFetchedNth(2, {
-          url: 'https://api.example.com/foo',
+        expect(fetch).toHaveFetchedNth(2, 'https://api.example.com/foo', {
           body: {
             query,
             extensions: {
@@ -145,8 +142,7 @@ describe('constructing requests', () => {
 
         expect(data).toEqual({ me: 'james' });
         expect(fetch).toBeCalledTimes(2);
-        expect(fetch).toHaveFetchedNth(1, {
-          url: 'https://api.example.com/foo',
+        expect(fetch).toHaveFetchedNth(1, 'https://api.example.com/foo', {
           body: {
             variables: { id: '1' },
             extensions: {
@@ -157,9 +153,7 @@ describe('constructing requests', () => {
             }
           },
         });
-
-        expect(fetch).toHaveFetchedNth(2, {
-          url: 'https://api.example.com/foo',
+        expect(fetch).toHaveFetchedNth(2, 'https://api.example.com/foo', {
           body: {
             query,
             variables: { id: '1' },
@@ -190,9 +184,8 @@ describe('constructing requests', () => {
 
         expect(data).toEqual({ me: 'james' });
         expect(fetch).toBeCalledTimes(1);
-        expect(fetch).toHaveFetched({
-          url: 'https://api.example.com/foo',
-          body: {
+        expect(fetch).toHaveFetched('https://api.example.com/foo', {
+            body: {
             extensions: {
               persistedQuery: {
                 version: 1,
@@ -221,8 +214,7 @@ describe('constructing requests', () => {
 
         expect(data).toEqual({ me: 'james' });
         expect(fetch).toBeCalledTimes(1);
-        expect(fetch).toHaveFetched({
-          url: 'https://api.example.com/foo',
+        expect(fetch).toHaveFetched('https://api.example.com/foo', {
           body: {
             variables: { id: '1' },
             extensions: {
@@ -259,6 +251,25 @@ describe('fetcher', () => {
 
   });
 
+  it('supports a custom fetcher, like `make-fetch-happen`', async () => {
+    const injectedFetch =
+      makeFetchHappenFetcher.mockJSONResponseOnce({ data: { me: 'james' } });
+    const DataSource = new RemoteGraphQLDataSource({
+      url: 'https://api.example.com/foo',
+      fetcher: injectedFetch,
+    });
+
+    const { data } = await DataSource.process({
+      request: {
+        query: '{ me { name } }',
+        variables: { id: '1' },
+      },
+      context: {},
+    });
+
+    expect(injectedFetch).toHaveBeenCalled();
+    expect(data).toEqual({ me: 'james' });
+  })
 });
 
 describe('willSendRequest', () => {
@@ -281,8 +292,7 @@ describe('willSendRequest', () => {
     });
 
     expect(data).toEqual({ me: 'james' });
-    expect(fetch).toHaveFetched({
-      url: 'https://api.example.com/foo',
+    expect(fetch).toHaveFetched('https://api.example.com/foo', {
       body: {
         query: '{ me { name } }',
         variables: JSON.stringify({ id: '1' }),
@@ -309,8 +319,7 @@ describe('willSendRequest', () => {
     });
 
     expect(data).toEqual({ me: 'james' });
-    expect(fetch).toHaveFetched({
-      url: 'https://api.example.com/foo',
+    expect(fetch).toHaveFetched('https://api.example.com/foo', {
       body: {
         query: '{ me { name } }',
         variables: { id: '1' },