Fix regression introduced in 0.9.4 which caused the reference guides to fail

Author: Dom Harrington

packages/api-explorer/__tests__/index.test.jsx

@@ -151,13 +151,26 @@ describe('oas', () => {
     expect(explorer.find('Doc').get(0).props.oas).toBe(oas);
   });
 
+  // Of course... `typeof null === 'object'`
+  it('should not error if `doc.api.apiSetting` is null', () => {
+    const explorer = shallow(
+      <ApiExplorer
+        {...props}
+        docs={[
+          Object.assign({}, baseDoc, {
+            api: { method: 'get', apiSetting: null },
+          }),
+        ]}
+      />,
+    );
+
+    expect(explorer.find('Doc').get(0).props.oas).toEqual({});
+  });
+
   it('should set it to empty object', () => {
     const explorer = shallow(
       <ApiExplorer
         {...props}
-        oasFiles={{
-          'api-setting': oas,
-        }}
         docs={[baseDoc]}
       />,
     );

packages/api-explorer/src/index.jsx

@@ -50,7 +50,7 @@ class ApiExplorer extends React.Component {
     const apiSetting =
       doc.category.apiSetting ||
       (typeof doc.api.apiSetting === 'string' && doc.api.apiSetting) ||
-      (typeof doc.api.apiSetting === 'object' && doc.api.apiSetting._id);
+      (typeof doc.api.apiSetting === 'object' && doc.api.apiSetting && doc.api.apiSetting._id);
 
     return this.props.oasFiles[apiSetting];
   }