[relay] Refactor and move type recognition to type files.

schema/article.js

@@ -58,6 +58,8 @@ const Article = {
     },
   },
   resolve: (root, { id }) => positron(`articles/${id}`),
+  // ObjectIdentification
+  isType: (obj) => obj.title !== undefined && obj.author !== undefined,
 };
 
 export default Article;

schema/artist/index.js

@@ -491,6 +491,8 @@ const Artist = {
     },
   },
   resolve: (root, { id }) => gravity(`artist/${id}`),
+  // ObjectIdentification
+  isType: (obj) => obj.birthday !== undefined && obj.artworks_count !== undefined,
 };
 
 export default Artist;

schema/artwork/index.js

@@ -462,6 +462,8 @@ const Artwork = {
     },
   },
   resolve: (root, { id }) => gravity(`artwork/${id}`),
+  // ObjectIdentification
+  isType: (obj) => obj.title !== undefined && obj.artists !== undefined,
 };
 
 export default Artwork;

schema/object_identification.js

@@ -1,6 +1,4 @@
-import gravity from '../lib/loaders/gravity';
-import positron from '../lib/loaders/positron';
-
+import _ from 'lodash';
 import {
   fromGlobalId,
   toGlobalId,
@@ -11,6 +9,12 @@ import {
   GraphQLInterfaceType,
 } from 'graphql';
 
+const SupportedTypes = {
+  types: ['Article', 'Artist', 'Artwork', 'PartnerShow'],
+  // To prevent circular dependencies, when this file is loaded, the modules are lazily loaded.
+  typeModule: _.memoize(type => require(`./${_.snakeCase(type)}`).default),
+};
+
 // Because we use a custom Node ID, we duplicate and slightly adjust the code from:
 // https://github.com/graphql/graphql-relay-js/blob/master/src/node/node.js
 
@@ -24,16 +28,11 @@ const NodeInterface = new GraphQLInterfaceType({
     },
   }),
   resolveType: (obj) => {
-    if (obj.birthday !== undefined && obj.artworks_count !== undefined) {
-      return require('./artist').default.type;
-    } else if (obj.title !== undefined && obj.artists !== undefined) {
-      return require('./artwork').default.type;
-    } else if (obj.title !== undefined && obj.author !== undefined) {
-      return require('./article').default.type;
-    } else if (obj.partner !== undefined && obj.display_on_partner_profile !== undefined) {
-      return require('./partner_show').default.type;
-    }
-    return null;
+    const mod = _.chain(SupportedTypes.types)
+      .map(type => SupportedTypes.typeModule(type))
+      .find(m => m.isType(obj))
+      .value();
+    return mod && mod.type;
   },
 });
 
@@ -47,19 +46,11 @@ const NodeField = {
       description: 'The ID of the object',
     },
   },
-  resolve: (_, { __id }) => {
+  resolve: (root, { __id }) => {
     const { type, id } = fromGlobalId(__id);
-    switch (type) {
-      case 'Artist':
-        return gravity(`artist/${id}`);
-      case 'Artwork':
-        return gravity(`artwork/${id}`);
-      case 'Article':
-        return positron(`articles/${id}`);
-      case 'PartnerShow':
-        return gravity(`show/${id}`);
-      default:
-        return null;
+    if (_.includes(SupportedTypes.types, type)) {
+      // Re-uses (slightly abuses) the existing GraphQL `resolve` function.
+      return SupportedTypes.typeModule(type).resolve(null, { id });
     }
   },
 };

schema/partner_show.js

@@ -268,6 +268,8 @@ const PartnerShow = {
         return show;
       });
   },
+  // ObjectIdentification
+  isType: (obj) => obj.partner !== undefined && obj.display_on_partner_profile !== undefined,
 };
 
 export default PartnerShow;

test/schema/object_identification.js

@@ -8,27 +8,23 @@ describe('Global Identification', () => {
   const Artist = schema.__get__('Artist');
   const Artwork = schema.__get__('Artwork');
   const PartnerShow = schema.__get__('PartnerShow');
-  const ObjectIdentification = schema.__get__('ObjectIdentification');
 
   afterEach(() => {
     Article.__ResetDependency__('positron');
     Artist.__ResetDependency__('gravity');
     Artwork.__ResetDependency__('gravity');
     PartnerShow.__ResetDependency__('gravity');
-    ObjectIdentification.__ResetDependency__('gravity');
   });
 
   describe('for an Article', () => {
     beforeEach(() => {
-      [Article, ObjectIdentification].forEach((mod) => {
-        mod.__Rewire__('positron', sinon.stub().returns(
-          Promise.resolve({
-            id: 'foo-bar',
-            title: 'Nightlife at the Foo Bar',
-            author: 'Artsy Editorial',
-          })
-        ));
-      });
+      Article.__Rewire__('positron', sinon.stub().returns(
+        Promise.resolve({
+          id: 'foo-bar',
+          title: 'Nightlife at the Foo Bar',
+          author: 'Artsy Editorial',
+        })
+      ));
     });
 
     it('generates a Global ID', () => {
@@ -76,15 +72,13 @@ describe('Global Identification', () => {
 
   describe('for an Artist', () => {
     beforeEach(() => {
-      [Artist, ObjectIdentification].forEach((mod) => {
-        mod.__Rewire__('gravity', sinon.stub().returns(
-          Promise.resolve({
-            id: 'foo-bar',
-            birthday: null,
-            artworks_count: 42,
-          })
-        ));
-      });
+      Artist.__Rewire__('gravity', sinon.stub().returns(
+        Promise.resolve({
+          id: 'foo-bar',
+          birthday: null,
+          artworks_count: 42,
+        })
+      ));
     });
 
     it('generates a Global ID', () => {
@@ -132,15 +126,13 @@ describe('Global Identification', () => {
 
   describe('for an Artwork', () => {
     beforeEach(() => {
-      [Artwork, ObjectIdentification].forEach((mod) => {
-        mod.__Rewire__('gravity', sinon.stub().returns(
-          Promise.resolve({
-            id: 'foo-bar',
-            title: 'For baz',
-            artists: null,
-          })
-        ));
-      });
+      Artwork.__Rewire__('gravity', sinon.stub().returns(
+        Promise.resolve({
+          id: 'foo-bar',
+          title: 'For baz',
+          artists: null,
+        })
+      ));
     });
 
     it('generates a Global ID', () => {
@@ -188,16 +180,14 @@ describe('Global Identification', () => {
 
   describe('for a PartnerShow', () => {
     beforeEach(() => {
-      [PartnerShow, ObjectIdentification].forEach((mod) => {
-        mod.__Rewire__('gravity', sinon.stub().returns(
-          Promise.resolve({
-            id: 'foo-bar',
-            displayable: true,
-            partner: { id: 'for-baz' },
-            display_on_partner_profile: true,
-          })
-        ));
-      });
+      PartnerShow.__Rewire__('gravity', sinon.stub().returns(
+        Promise.resolve({
+          id: 'foo-bar',
+          displayable: true,
+          partner: { id: 'for-baz' },
+          display_on_partner_profile: true,
+        })
+      ));
     });
 
     it('generates a Global ID', () => {