From e8816bfa67b79d30bf9dc0cfcec07aa70ca25df3 Mon Sep 17 00:00:00 2001
From: stefanprobst <stefan.probst@univie.ac.at>
Date: Mon, 25 Mar 2019 10:02:57 +0100
Subject: [PATCH] fix(schema): Preserve resolvers on ___NODE fields (#12806)

---
 .../src/schema/infer/__tests__/merge-types.js | 42 +++++++++++++++++++
 .../src/schema/infer/add-inferred-fields.js   | 18 ++++----
 2 files changed, 52 insertions(+), 8 deletions(-)

diff --git a/packages/gatsby/src/schema/infer/__tests__/merge-types.js b/packages/gatsby/src/schema/infer/__tests__/merge-types.js
index f6a9e6ec5695b..bef4a151e3c7c 100644
--- a/packages/gatsby/src/schema/infer/__tests__/merge-types.js
+++ b/packages/gatsby/src/schema/infer/__tests__/merge-types.js
@@ -35,6 +35,12 @@ const nodes = [
       },
     ],
   },
+  {
+    id: `id2`,
+    internal: { type: `LinkTest` },
+    link___NODE: `id1`,
+    links___NODE: [`id1`],
+  },
 ]
 
 describe(`merges explicit and inferred type definitions`, () => {
@@ -276,4 +282,40 @@ describe(`merges explicit and inferred type definitions`, () => {
     // Date resolvers
     expect(fields.explicitDate.resolve).toBeUndefined()
   })
+
+  it(`preserves foreign-key resolvers on ___NODE fields when noDefaultResolvers: false`, async () => {
+    const typeDefs = `
+      type LinkTest implements Node {
+        link: Test!
+        links: [Test!]!
+      }
+    `
+    store.dispatch({ type: `CREATE_TYPES`, payload: typeDefs })
+
+    await build({})
+    const { schema } = store.getState()
+    const { link, links } = schema.getType(`LinkTest`).getFields()
+    expect(link.type.toString()).toBe(`Test!`)
+    expect(links.type.toString()).toBe(`[Test!]!`)
+    expect(link.resolve).toBeDefined()
+    expect(links.resolve).toBeDefined()
+  })
+
+  it(`ignores foreign-key resolvers on ___NODE fields when noDefaultResolvers: true`, async () => {
+    const typeDefs = `
+      type LinkTest implements Node @infer(noDefaultResolvers: true) {
+        link: Test!
+        links: [Test!]!
+      }
+    `
+    store.dispatch({ type: `CREATE_TYPES`, payload: typeDefs })
+
+    await build({})
+    const { schema } = store.getState()
+    const { link, links } = schema.getType(`LinkTest`).getFields()
+    expect(link.type.toString()).toBe(`Test!`)
+    expect(links.type.toString()).toBe(`[Test!]!`)
+    expect(link.resolve).toBeUndefined()
+    expect(links.resolve).toBeUndefined()
+  })
 })
diff --git a/packages/gatsby/src/schema/infer/add-inferred-fields.js b/packages/gatsby/src/schema/infer/add-inferred-fields.js
index 1beb8153050d2..35079a5c17a2c 100644
--- a/packages/gatsby/src/schema/infer/add-inferred-fields.js
+++ b/packages/gatsby/src/schema/infer/add-inferred-fields.js
@@ -102,25 +102,27 @@ const addInferredFieldsImpl = ({
       let lists = 0
       let namedFieldType = fieldType
       while (namedFieldType.ofType) {
-        namedFieldType = namedFieldType.ofType
         if (namedFieldType instanceof GraphQLList) {
           lists++
         }
+        namedFieldType = namedFieldType.ofType
       }
 
-      if (arrays === lists) {
+      const namedInferredTypeName =
+        typeof namedInferredType === `string`
+          ? namedInferredType
+          : namedInferredType.getTypeName()
+
+      if (arrays === lists && namedFieldType.name === namedInferredTypeName) {
         if (
           namedFieldType instanceof GraphQLObjectType &&
-          typeof namedInferredType !== `string` &&
-          namedFieldType.name === namedInferredType.getTypeName()
+          namedInferredType instanceof ObjectTypeComposer
         ) {
           const fieldTypeComposer = typeComposer.getFieldTC(key)
           const inferredFields = namedInferredType.getFields()
           fieldTypeComposer.addFields(inferredFields)
-        } else if (
-          addDefaultResolvers &&
-          namedFieldType.name === namedInferredType
-        ) {
+        }
+        if (addDefaultResolvers) {
           let field = typeComposer.getField(key)
           if (!field.type) {
             field = {