More resolveType fixes, this time for Relay's nodeDefinitions (#51)

* More resolveType fixes, this time for Relay's nodeDefinitions

* Add a loadExtension helper

* Use createContext in test helpers

src/context.js

@@ -1,4 +1,5 @@
 import createLoaders from './loaders'
+import { loadExtension } from './extensions'
 
 const debug = require('debug')('graphbrainz:context')
 
@@ -27,6 +28,6 @@ export function createContext(options = {}) {
   const context = { client, loaders }
   const { extensions = [] } = options
   return extensions.reduce((context, extension) => {
-    return extendContext(extension, context, options)
+    return extendContext(loadExtension(extension), context, options)
   }, context)
 }

src/extensions/index.js

@@ -0,0 +1,18 @@
+export function loadExtension(extensionModule) {
+  let extension
+  if (typeof extensionModule === 'string') {
+    extension = require(extensionModule)
+  } else {
+    extension = extensionModule
+  }
+  if (extension == null || typeof extension !== 'object') {
+    throw new Error(
+      `Expected ${extensionModule} to export an extension but instead ` +
+        `got: ${extension}`
+    )
+  } else if (extension.default) {
+    // ECMAScript module interop.
+    extension = extension.default
+  }
+  return extension
+}

src/index.js

@@ -6,40 +6,29 @@ import MusicBrainz from './api'
 import schema, { createSchema } from './schema'
 import { createContext } from './context'
 
-const debug = require('debug')('graphbrainz')
-
 const formatError = err => ({
   message: err.message,
   locations: err.locations,
   stack: err.stack
 })
 
+export const defaultExtensions = [
+  require.resolve('./extensions/cover-art-archive'),
+  require.resolve('./extensions/fanart-tv'),
+  require.resolve('./extensions/mediawiki'),
+  require.resolve('./extensions/the-audio-db')
+]
+
 const middleware = (
   {
     client = new MusicBrainz(),
     extensions = process.env.GRAPHBRAINZ_EXTENSIONS
       ? JSON.parse(process.env.GRAPHBRAINZ_EXTENSIONS)
-      : [
-          './extensions/cover-art-archive',
-          './extensions/fanart-tv',
-          './extensions/mediawiki',
-          './extensions/the-audio-db'
-        ],
+      : defaultExtensions,
     ...middlewareOptions
   } = {}
 ) => {
-  debug(`Loading ${extensions.length} extension(s).`)
-  const options = {
-    client,
-    extensions: extensions.map(extensionModule => {
-      if (typeof extensionModule === 'object') {
-        return extensionModule
-      }
-      const extension = require(extensionModule)
-      return extension.default ? extension.default : extension
-    }),
-    ...middlewareOptions
-  }
+  const options = { client, extensions, ...middlewareOptions }
   const DEV = process.env.NODE_ENV !== 'production'
   const graphiql = DEV || process.env.GRAPHBRAINZ_GRAPHIQL === 'true'
   return graphqlHTTP({

src/schema.js

@@ -2,6 +2,7 @@ import { GraphQLSchema, GraphQLObjectType, extendSchema, parse } from 'graphql'
 import { addResolveFunctionsToSchema } from 'graphql-tools'
 import { lookup, browse, search } from './queries'
 import { nodeField } from './types/node'
+import { loadExtension } from './extensions'
 
 const debug = require('debug')('graphbrainz:schema')
 
@@ -45,9 +46,9 @@ export function applyExtension(extension, schema, options = {}) {
 }
 
 export function createSchema(schema, options = {}) {
-  const extensions = options.extensions || []
+  const { extensions = [] } = options
   return extensions.reduce((updatedSchema, extension) => {
-    return applyExtension(extension, updatedSchema, options)
+    return applyExtension(loadExtension(extension), updatedSchema, options)
   }, schema)
 }
 

src/types/entity.js

@@ -1,21 +1,24 @@
 import { GraphQLInterfaceType } from 'graphql'
 import { mbid, connectionWithExtras } from './helpers'
 
+const debug = require('debug')('graphbrainz:types/entity')
+
 const Entity = new GraphQLInterfaceType({
   name: 'Entity',
   description: 'An entity in the MusicBrainz schema.',
   resolveType(value, context, info) {
     if (value._type) {
-      const typeMap = info.schema.getTypeMap()
       let originalType
       try {
         originalType = require(`./${value._type}`).default
       } catch (err) {
+        debug(`Failed to load type: ${value._type}`)
         return
       }
       // Don't use `originalType`! The schema may have been extended in which
       // case the types have all been replaced. Instead, find the current type
       // of the same name.
+      const typeMap = info.schema.getTypeMap()
       return typeMap[originalType.name]
     }
   },

src/types/node.js

@@ -13,13 +13,21 @@ const { nodeInterface, nodeField } = nodeDefinitions(
     const entityType = toDashed(type)
     return loaders.lookup.load([entityType, id])
   },
-  obj => {
+  (obj, context, info) => {
     const type = TYPE_MODULES[obj._type] || obj._type
-    try {
-      return require(`./${type}`).default
-    } catch (err) {
-      debug(`Failed to load type: ${type}`)
-      return null
+    if (type) {
+      let originalType
+      try {
+        originalType = require(`./${type}`).default
+      } catch (err) {
+        debug(`Failed to load type: ${type}`)
+        return
+      }
+      // Don't use `originalType`! The schema may have been extended in which
+      // case the types have all been replaced. Instead, find the current type
+      // of the same name.
+      const typeMap = info.schema.getTypeMap()
+      return typeMap[originalType.name]
     }
   }
 )

test/_schema.js

@@ -1,8 +1,11 @@
 import test from 'ava'
 import { graphql } from 'graphql'
-import schema from '../src/schema'
+import schemas from './helpers/schema'
 import context from './helpers/context'
 
+const TEST_SCHEMA = process.env.TEST_SCHEMA || 'baseSchema'
+const schema = schemas[TEST_SCHEMA]
+
 function testData(t, query, handler) {
   return graphql(schema, query, null, context).then(result => {
     if (result.errors !== undefined) {

test/base-schema.js

@@ -0,0 +1,2 @@
+process.env.TEST_SCHEMA = 'baseSchema'
+require('./_schema')

test/extended-schema.js

@@ -0,0 +1,2 @@
+process.env.TEST_SCHEMA = 'extendedSchema'
+require('./_schema')

test/helpers/context.js

@@ -1,7 +1,4 @@
-import createLoaders from '../../src/loaders'
+import { createContext } from '../../src/context'
 import client from './client/musicbrainz'
 
-export default {
-  client,
-  loaders: createLoaders(client)
-}
+export default createContext({ client })

test/helpers/schema.js

@@ -0,0 +1,7 @@
+import schema, { createSchema } from '../../src/schema'
+import { defaultExtensions } from '../../src'
+
+export default {
+  baseSchema: schema,
+  extendedSchema: createSchema(schema, { extensions: defaultExtensions })
+}

test/snapshots/base-schema.js.md

@@ -0,0 +1,81 @@
+# Snapshot report for `test/base-schema.js`
+
+The actual snapshot is saved in `base-schema.js.snap`.
+
+Generated by [AVA](https://ava.li).
+
+## areas have a type and typeID
+
+> Snapshot 1
+
+    {
+      search: {
+        areas: {
+          nodes: [
+            {
+              name: 'Germany',
+              type: 'Country',
+              typeID: '06dd0ae4-8c74-30bb-b43d-95dcedf961de',
+            },
+            {
+              name: 'East Germany',
+              type: 'Country',
+              typeID: '06dd0ae4-8c74-30bb-b43d-95dcedf961de',
+            },
+            {
+              name: 'New Germany',
+              type: 'City',
+              typeID: '6fd8f29a-3d0a-32fc-980d-ea697b69da78',
+            },
+            {
+              name: 'New Germany',
+              type: 'City',
+              typeID: '6fd8f29a-3d0a-32fc-980d-ea697b69da78',
+            },
+            {
+              name: 'Brakel',
+              type: 'City',
+              typeID: '6fd8f29a-3d0a-32fc-980d-ea697b69da78',
+            },
+          ],
+        },
+      },
+    
+
+## baseSchema: areas have a type and typeID
+
+> Snapshot 1
+
+    {
+      search: {
+        areas: {
+          nodes: [
+            {
+              name: 'Germany',
+              type: 'Country',
+              typeID: '06dd0ae4-8c74-30bb-b43d-95dcedf961de',
+            },
+            {
+              name: 'East Germany',
+              type: 'Country',
+              typeID: '06dd0ae4-8c74-30bb-b43d-95dcedf961de',
+            },
+            {
+              name: 'New Germany',
+              type: 'City',
+              typeID: '6fd8f29a-3d0a-32fc-980d-ea697b69da78',
+            },
+            {
+              name: 'New Germany',
+              type: 'City',
+              typeID: '6fd8f29a-3d0a-32fc-980d-ea697b69da78',
+            },
+            {
+              name: 'Brakel',
+              type: 'City',
+              typeID: '6fd8f29a-3d0a-32fc-980d-ea697b69da78',
+            },
+          ],
+        },
+      },
+    }

test/snapshots/extended-schema.js.md

@@ -0,0 +1,81 @@
+# Snapshot report for `test/extended-schema.js`
+
+The actual snapshot is saved in `extended-schema.js.snap`.
+
+Generated by [AVA](https://ava.li).
+
+## areas have a type and typeID
+
+> Snapshot 1
+
+    {
+      search: {
+        areas: {
+          nodes: [
+            {
+              name: 'Germany',
+              type: 'Country',
+              typeID: '06dd0ae4-8c74-30bb-b43d-95dcedf961de',
+            },
+            {
+              name: 'East Germany',
+              type: 'Country',
+              typeID: '06dd0ae4-8c74-30bb-b43d-95dcedf961de',
+            },
+            {
+              name: 'New Germany',
+              type: 'City',
+              typeID: '6fd8f29a-3d0a-32fc-980d-ea697b69da78',
+            },
+            {
+              name: 'New Germany',
+              type: 'City',
+              typeID: '6fd8f29a-3d0a-32fc-980d-ea697b69da78',
+            },
+            {
+              name: 'Brakel',
+              type: 'City',
+              typeID: '6fd8f29a-3d0a-32fc-980d-ea697b69da78',
+            },
+          ],
+        },
+      },
+    
+
+## extendedSchema: areas have a type and typeID
+
+> Snapshot 1
+
+    {
+      search: {
+        areas: {
+          nodes: [
+            {
+              name: 'Germany',
+              type: 'Country',
+              typeID: '06dd0ae4-8c74-30bb-b43d-95dcedf961de',
+            },
+            {
+              name: 'East Germany',
+              type: 'Country',
+              typeID: '06dd0ae4-8c74-30bb-b43d-95dcedf961de',
+            },
+            {
+              name: 'New Germany',
+              type: 'City',
+              typeID: '6fd8f29a-3d0a-32fc-980d-ea697b69da78',
+            },
+            {
+              name: 'New Germany',
+              type: 'City',
+              typeID: '6fd8f29a-3d0a-32fc-980d-ea697b69da78',
+            },
+            {
+              name: 'Brakel',
+              type: 'City',
+              typeID: '6fd8f29a-3d0a-32fc-980d-ea697b69da78',
+            },
+          ],
+        },
+      },
+    }

test/snapshots/schema.js.md

@@ -1,43 +0,0 @@
-# Snapshot report for `test/schema.js`
-
-The actual snapshot is saved in `schema.js.snap`.
-
-Generated by [AVA](https://ava.li).
-
-## areas have a type and typeID
-
-> Snapshot 1
-
-    {
-      search: {
-        areas: {
-          nodes: [
-            {
-              name: 'Germany',
-              type: 'Country',
-              typeID: '06dd0ae4-8c74-30bb-b43d-95dcedf961de',
-            },
-            {
-              name: 'East Germany',
-              type: 'Country',
-              typeID: '06dd0ae4-8c74-30bb-b43d-95dcedf961de',
-            },
-            {
-              name: 'New Germany',
-              type: 'City',
-              typeID: '6fd8f29a-3d0a-32fc-980d-ea697b69da78',
-            },
-            {
-              name: 'New Germany',
-              type: 'City',
-              typeID: '6fd8f29a-3d0a-32fc-980d-ea697b69da78',
-            },
-            {
-              name: 'Brakel',
-              type: 'City',
-              typeID: '6fd8f29a-3d0a-32fc-980d-ea697b69da78',
-            },
-          ],
-        },
-      },
-    }

test/types/node.js

@@ -1,11 +1,15 @@
 import test from 'ava'
 import Node from '../../src/types/node'
 import ReleaseGroup from '../../src/types/release-group'
+import schema from '../../src/schema'
 
 test('loads types from their module', t => {
-  t.is(Node.resolveType({ _type: 'release-group' }), ReleaseGroup)
+  t.is(
+    Node.resolveType({ _type: 'release-group' }, {}, { schema }),
+    ReleaseGroup
+  )
 })
 
-test('returns null for unknown types', t => {
-  t.is(Node.resolveType({ _type: 'foo' }), null)
+test('returns undefined for unknown types', t => {
+  t.is(Node.resolveType({ _type: 'foo' }, {}, { schema }), undefined)
 })