Enables parsing of application/hal+json as JSON in RESTDataSource (#1853)

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 - Allow an optional function to resolve the `rootValue`, passing the `DocumentNode` AST to determine the value. [PR #1555](https://github.com/apollographql/apollo-server/pull/1555)
 - Follow-up on the work in [PR #1516](https://github.com/apollographql/apollo-server/pull/1516) to also fix missing insertion cursor/caret when a custom GraphQL configuration is specified which doesn't specify its own `cursorShape` property. [PR #1607](https://github.com/apollographql/apollo-server/pull/1607)
+- Allow JSON parsing in `RESTDataSource` of Content Type `application/hal+json`. [PR ##185](https://github.com/apollographql/apollo-server/pull/1853)
 
 ### v2.1.0
 

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

@@ -104,7 +104,11 @@ export abstract class RESTDataSource<TContext = any> extends DataSource {
 
   protected parseBody(response: Response): Promise<object | string> {
     const contentType = response.headers.get('Content-Type');
-    if (contentType && contentType.startsWith('application/json')) {
+    if (
+      contentType &&
+      (contentType.startsWith('application/json') ||
+        contentType.startsWith('application/hal+json'))
+    ) {
       return response.json();
     } else {
       return response.text();

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

@@ -392,6 +392,27 @@ describe('RESTDataSource', () => {
       expect(data).toEqual({ foo: 'bar' });
     });
 
+    it('returns data as parsed JSON when Content-Type is application/hal+json', async () => {
+      const dataSource = new class extends RESTDataSource {
+        baseURL = 'https://api.example.com';
+
+        getFoo() {
+          return this.get('foo');
+        }
+      }();
+
+      dataSource.httpCache = httpCache;
+
+      fetch.mockJSONResponseOnce(
+        { foo: 'bar' },
+        { 'Content-Type': 'application/hal+json' },
+      );
+
+      const data = await dataSource.getFoo();
+
+      expect(data).toEqual({ foo: 'bar' });
+    });
+
     it('returns data as a string when Content-Type is text/plain', async () => {
       const dataSource = new class extends RESTDataSource {
         baseURL = 'https://api.example.com';