fix: require-selections requireAllFields false positives

packages/plugin/src/rules/require-selections/index.test.ts

@@ -55,6 +55,7 @@ const USER_POST_SCHEMA = /* GraphQL */ `
   type Post {
     id: ID
     title: String
+    content: String
     author: [User!]!
   }
 
@@ -316,6 +317,30 @@ ruleTester.run<RuleOptions, true>('require-selections', rule, {
         }
       `,
     },
+    {
+      name: 'should require only extant fields with `requireAllFields` option',
+      code: /* GraphQL */ `
+        {
+          user {
+            id
+            posts {
+              id
+              title
+              content
+            }
+          }
+        }
+      `,
+      options: [{ requireAllFields: true, fieldName: ['id', 'title', 'content'] }],
+      parserOptions: {
+        graphQLConfig: {
+          schema: USER_POST_SCHEMA,
+          documents: `
+          fragment Example on User { id }
+          `,
+        },
+      },
+    },
   ],
   invalid: [
     {
@@ -523,7 +548,13 @@ ruleTester.run<RuleOptions, true>('require-selections', rule, {
           documents: '{ foo }',
         },
       },
-      errors: 1,
+      errors: [
+        {
+          message:
+            "Field `hasId.name` must be selected when it's available on a type.\n" +
+            'Include it in your selection set.',
+        },
+      ],
     },
   ],
 });

packages/plugin/src/rules/require-selections/index.ts

@@ -201,20 +201,27 @@ export const rule: GraphQLESLintRule<RuleOptions, true> = {
 
       function checkFields(rawType: GraphQLInterfaceType | GraphQLObjectType) {
         const fields = rawType.getFields();
-        const hasIdFieldInType = idNames.some(name => fields[name]);
 
-        if (!hasIdFieldInType) {
+        // Only check fields which are actually present on this type
+        const idFieldsInType = idNames.filter(name => fields[name]);
+
+        // Type doesn't implement any of the `fieldNames`
+        if (idFieldsInType.length === 0) {
           return;
         }
 
         checkFragments(node as GraphQLESTreeNode<SelectionSetNode>);
 
         if (requireAllFields) {
-          for (const idName of idNames) {
+          for (const idName of idFieldsInType) {
+            // For each `fieldName` present on this type, check it's in the
+            // selection separately
             report([idName]);
           }
         } else {
-          report(idNames);
+          // Pass the `fieldNames` present on this type together; `report` will
+          // pass if _any_ of them are selected
+          report(idFieldsInType);
         }
       }