fix(gatsby): tolerate null object values (#12756)

fix(gatsby): tolerate null object values (#12756)

Author: freiksenet

packages/gatsby/src/schema/infer/__tests__/__snapshots__/infer.js.snap

@@ -167,6 +167,16 @@ Object {
                 ],
               },
             ],
+            "anObjectArrayWithNull": Array [
+              Object {
+                "anotherObjectArray": Array [
+                  Object {
+                    "baz": "quz",
+                  },
+                ],
+              },
+              null,
+            ],
             "date": "1012",
             "deepObject": Object {
               "deepObject": Object {
@@ -216,6 +226,16 @@ Object {
                 ],
               },
             ],
+            "anObjectArrayWithNull": Array [
+              Object {
+                "anotherObjectArray": Array [
+                  Object {
+                    "baz": "quz",
+                  },
+                ],
+              },
+              null,
+            ],
             "date": "1984",
             "deepObject": null,
             "domain": null,

packages/gatsby/src/schema/infer/__tests__/infer.js

@@ -28,6 +28,7 @@ const makeNodes = () => [
       { aString: `some string`, aNumber: 2, anArray: [1, 2] },
       { anotherObjectArray: [{ bar: 10 }] },
     ],
+    anObjectArrayWithNull: [{ anotherObjectArray: [{ baz: `quz` }] }, null],
     deepObject: {
       level: 1,
       deepObject: {
@@ -63,6 +64,7 @@ const makeNodes = () => [
     anArray: [1, 2, 5, 4],
     aNestedArray: [[1, 2, 3, 4]],
     anObjectArray: [{ anotherObjectArray: [{ baz: `quz` }] }],
+    anObjectArrayWithNull: [{ anotherObjectArray: [{ baz: `quz` }] }, null],
     "with space": 3,
     "with-hyphen": 4,
     123: 24,
@@ -987,6 +989,11 @@ describe(`GraphQL type inference`, () => {
             baz
           }
         },
+        anObjectArrayWithNull {
+          anotherObjectArray {
+            baz
+          }
+        }
         deepObject {
           level
           deepObject {

packages/gatsby/src/schema/infer/example-value.js

@@ -22,11 +22,12 @@ module.exports = {
 }
 
 const getExampleObject = ({
-  nodes,
+  nodes: rawNodes,
   prefix,
   typeConflictReporter,
   ignoreFields = [],
 }) => {
+  const nodes = rawNodes.filter(node => node != null)
   const allKeys = nodes.reduce(
     (acc, node) =>
       Object.keys(node).forEach(

packages/gatsby/src/schema/utils/get-value-at.js

@@ -3,7 +3,9 @@ const getValueAt = (obj, selector) => {
   return selectors.reduce((acc, key) => {
     if (acc && typeof acc === `object`) {
       if (Array.isArray(acc)) {
-        return acc.map(a => a[key]).filter(a => a !== undefined)
+        return acc
+          .map(a => (a && typeof a === `object` ? a[key] : undefined))
+          .filter(a => a !== undefined)
       }
       return acc[key]
     }