Add ignore config to no-unused-fields rule

.changeset/lovely-emus-shake.md

@@ -0,0 +1,5 @@
+---
+"@graphql-eslint/eslint-plugin": major
+---
+
+Add ignore config to `no-unused-fields` rule

packages/plugin/__tests__/no-unused-fields.spec.ts

@@ -94,6 +94,27 @@ ruleTester.run('no-unused-fields', rule, {
         },
       },
     },
+    {
+      name: 'should allow fields if they are ignored',
+      options: [{ ignoredFieldSelectors: ['FieldDefinition[name.value=firstName]'] }],
+      code: /* GraphQL */ `
+        type User {
+          id: ID!
+          firstName: String
+        }
+      `,
+      parserOptions: {
+        graphQLConfig: {
+          documents: /* GraphQL */ `
+            {
+              user(id: 1) {
+                id
+              }
+            }
+          `,
+        },
+      },
+    },
   ],
   invalid: [
     {

packages/plugin/src/rules/no-unused-fields.ts

@@ -1,10 +1,39 @@
-import { GraphQLSchema, TypeInfo, visit, visitWithTypeInfo } from 'graphql';
+import { FieldDefinitionNode, GraphQLSchema, TypeInfo, visit, visitWithTypeInfo } from 'graphql';
+import { FromSchema } from 'json-schema-to-ts';
+import { GraphQLESTreeNode } from '../estree-converter/types.js';
 import { SiblingOperations } from '../siblings.js';
-import { GraphQLESLintRule } from '../types.js';
+import { GraphQLESLintRule, GraphQLESLintRuleListener } from '../types.js';
 import { requireGraphQLSchemaFromContext, requireSiblingsOperations } from '../utils.js';
 
 const RULE_ID = 'no-unused-fields';
 
+const schema = {
+  type: 'array',
+  maxItems: 1,
+  items: {
+    type: 'object',
+    additionalProperties: false,
+    properties: {
+      ignoredFieldSelectors: {
+        type: 'array',
+        uniqueItems: true,
+        minItems: 1,
+        description: [
+          'Fields that will be ignored and are allowed to be unused.',
+          '',
+          '> These fields are defined by ESLint [`selectors`](https://eslint.org/docs/developer-guide/selectors). Paste or drop code into the editor in [ASTExplorer](https://astexplorer.net) and inspect the generated AST to compose your selector.',
+        ].join('\n'),
+        items: {
+          type: 'string',
+          pattern: '^FieldDefinition(.+)$',
+        },
+      },
+    },
+  },
+} as const;
+
+export type RuleOptions = FromSchema<typeof schema>;
+
 type UsedFields = Record<string, Set<string>>;
 
 let usedFieldsCache: UsedFields;
@@ -41,7 +70,7 @@ function getUsedFields(schema: GraphQLSchema, operations: SiblingOperations): Us
   return usedFieldsCache;
 }
 
-export const rule: GraphQLESLintRule = {
+export const rule: GraphQLESLintRule<RuleOptions> = {
   meta: {
     messages: {
       [RULE_ID]: 'Field "{{fieldName}}" is unused',
@@ -96,45 +125,74 @@ export const rule: GraphQLESLintRule = {
             }
           `,
         },
+        {
+          title: 'Correct (ignoring fields)',
+          usage: [{ ignoredFieldSelectors: ['FieldDefinition[name.value=lastName]'] }],
+          code: /* GraphQL */ `
+            type User {
+              id: ID!
+              firstName: String
+              lastName: String
+            }
+
+            type Query {
+              me: User
+            }
+
+            query {
+              me {
+                id
+                firstName
+              }
+            }
+          `,
+        },
       ],
     },
     type: 'suggestion',
-    schema: [],
+    schema,
     hasSuggestions: true,
   },
   create(context) {
     const schema = requireGraphQLSchemaFromContext(RULE_ID, context);
     const siblingsOperations = requireSiblingsOperations(RULE_ID, context);
     const usedFields = getUsedFields(schema, siblingsOperations);
+    const { ignoredFieldSelectors } = context.options[0] || {};
+    const selector = (ignoredFieldSelectors || []).reduce(
+      (acc, selector) => `${acc}:not(${selector})`,
+      'FieldDefinition',
+    );
 
-    return {
-      FieldDefinition(node) {
-        const fieldName = node.name.value;
-        const parentTypeName = node.parent.name.value;
-        const isUsed = usedFields[parentTypeName]?.has(fieldName);
-
-        if (isUsed) {
-          return;
-        }
-
-        context.report({
-          node: node.name,
-          messageId: RULE_ID,
-          data: { fieldName },
-          suggest: [
-            {
-              desc: `Remove \`${fieldName}\` field`,
-              fix(fixer) {
-                const sourceCode = context.getSourceCode() as any;
-                const tokenBefore = sourceCode.getTokenBefore(node);
-                const tokenAfter = sourceCode.getTokenAfter(node);
-                const isEmptyType = tokenBefore.type === '{' && tokenAfter.type === '}';
-                return fixer.remove((isEmptyType ? node.parent : node) as any);
-              },
+    const listener: GraphQLESLintRuleListener = (node: GraphQLESTreeNode<FieldDefinitionNode>) => {
+      const fieldName = node.name.value;
+      const parentTypeName = node.parent.name.value;
+      const isUsed = usedFields[parentTypeName]?.has(fieldName);
+
+      if (isUsed) {
+        return;
+      }
+
+      context.report({
+        node: node.name,
+        messageId: RULE_ID,
+        data: { fieldName },
+        suggest: [
+          {
+            desc: `Remove \`${fieldName}\` field`,
+            fix(fixer) {
+              const sourceCode = context.getSourceCode() as any;
+              const tokenBefore = sourceCode.getTokenBefore(node);
+              const tokenAfter = sourceCode.getTokenAfter(node);
+              const isEmptyType = tokenBefore.type === '{' && tokenAfter.type === '}';
+              return fixer.remove((isEmptyType ? node.parent : node) as any);
             },
-          ],
-        });
-      },
+          },
+        ],
+      });
+    };
+
+    return {
+      [selector]: listener,
     };
   },
 };

website/src/pages/rules/no-unused-fields.md

@@ -59,6 +59,49 @@ query {
 }
 ```
 
+### Correct (ignoring fields)
+
+```graphql
+# eslint @graphql-eslint/no-unused-fields: ['error', { ignoredFieldSelectors: ['FieldDefinition[name.value=lastName]'] }]
+
+type User {
+  id: ID!
+  firstName: String
+  lastName: String
+}
+
+type Query {
+  me: User
+}
+
+query {
+  me {
+    id
+    firstName
+  }
+}
+```
+
+## Config Schema
+
+The schema defines the following properties:
+
+### `ignoredFieldSelectors` (array)
+
+Fields that will be ignored and are allowed to be unused.
+
+> These fields are defined by ESLint
+> [`selectors`](https://eslint.org/docs/developer-guide/selectors) . Paste or drop code into the
+> editor in [ASTExplorer](https://astexplorer.net) and inspect the generated AST to compose your
+> selector.
+
+The object is an array with all elements of the type `string`.
+
+Additional restrictions:
+
+- Minimum items: `1`
+- Unique items: `true`
+
 ## Resources
 
 - [Rule source](https://github.com/B2o5T/graphql-eslint/tree/master/packages/plugin/src/rules/no-unused-fields.ts)