fix required-fields rule to work with inline fragments without a fiel…

…d ancestor

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ### vNEXT
 
+- Update the `required-fields` rule to handle inline fragments without field ancestors. PR by [Henry Q. Dineen](https://github.com/henryqdineen)
+
 ### v3.0.3
 
 - chore: Update dependency `graphql-tools` to `v4.0.4`. [PR #210](https://github.com/apollographql/eslint-plugin-graphql/pull/210)

src/customGraphQLValidationRules.js

@@ -63,11 +63,11 @@ export function RequiredFields(context, options) {
 
           const ancestorClone = [...ancestors];
 
-          let nearestField;
+          let nearestFieldOrExecutableDefinition;
           let nextAncestor;
 
-          // Now, walk up the ancestors, until you see a field.
-          while (!nearestField) {
+          // Now, walk up the ancestors, until you see a field or executable definition.
+          while (!nearestFieldOrExecutableDefinition) {
             nextAncestor = ancestorClone.pop();
 
             if (
@@ -77,19 +77,23 @@ export function RequiredFields(context, options) {
               return true;
             }
 
-            if (nextAncestor.kind === "Field") {
-              nearestField = nextAncestor;
+            if (
+              nextAncestor.kind === "Field" ||
+              nextAncestor.kind === "FragmentDefinition" ||
+              nextAncestor.kind === "OperationDefiniton"
+            ) {
+              nearestFieldOrExecutableDefinition = nextAncestor;
             }
           }
 
-          // If we never found a field, the query is malformed
-          if (!nearestField) {
+          // If we never found a field or executable definition, the query is malformed
+          if (!nearestFieldOrExecutableDefinition) {
             throw new Error(
-              "Inline fragment found inside document without a parent field."
+              "Inline fragment found inside document without a parent field, fragment definition, or operation definition."
             );
           }
 
-          // We found a field, but we never saw the field we were looking for in
+          // We found a field or executable definition, but we never saw the field we were looking for in
           // the intermediate selection sets.
           context.reportError(
             new GraphQLError(

test/validationRules/required-fields.js

@@ -81,6 +81,16 @@ const requiredFieldsTestCases = {
         }
       ]
     },
+    {
+      code:
+        "const x = gql`fragment GreetingOrStoryFragment on GreetingOrStory { ... on Greetings { hello } }`",
+      errors: [
+        {
+          message: `'id' field required on '... on Greetings'`,
+          type: "TaggedTemplateExpression"
+        }
+      ]
+    },
   ]
 };