Add an ignoredFields option for relay/unused-fields

Author: azz

README.md

@@ -52,14 +52,42 @@ The following rules support suppression within graphql tags:
 Supported rules can be suppressed by adding `# eslint-disable-next-line relay/name-of-rule` to the preceding line:
 
 ```js
-graphql`fragment foo on Page {
-  # eslint-disable-next-line relay/must-colocate-fragment-spreads
-  ...unused1
-}`
+graphql`
+  fragment foo on Page {
+    # eslint-disable-next-line relay/must-colocate-fragment-spreads
+    ...unused1
+  }
+`;
 ```
 
 Note that only the `eslint-disable-next-line` form of suppression works. `eslint-disable-line` doesn't currently work until graphql-js provides support for [parsing Comment nodes](https://github.com/graphql/graphql-js/issues/2241) in their AST.
 
+## Ignoring fields with `unused-fields`
+
+Sometimes you might have fields that are accessed by library code (outside the current file), for example:
+
+```js
+import getNodes from 'some/lib';
+
+graphql`
+  fragment foo on Page {
+    edges { # not directly accessed by this file
+      node { # not directly accessed by this file
+        name
+      }
+    }
+  }
+`;
+
+getNodes(foo).map(node => node.name);
+```
+
+You can ignore the `unused-fields` rule for these fields by providing the `ignoredFields` option.
+
+```js
+  'relay/unused-fields': ['warn', {ignoredFields: ['edges', 'node']}],
+```
+
 ## Contribute
 
 We actively welcome pull requests, learn how to [contribute](./CONTRIBUTING.md).

src/rule-unused-fields.js

@@ -92,6 +92,11 @@ function isPageInfoField(field) {
   }
 }
 
+function isIgnoredField(field, options = []) {
+  const {ignoredFields = []} = options[0] || {};
+  return ignoredFields.includes(field);
+}
+
 function rule(context) {
   let currentMethod = [];
   let foundMemberAccesses = {};
@@ -147,6 +152,7 @@ function rule(context) {
           if (
             !foundMemberAccesses[field] &&
             !isPageInfoField(field) &&
+            !isIgnoredField(field, context.options) &&
             // Do not warn for unused __typename which can be a workaround
             // when only interested in existence of an object.
             field !== '__typename'
@@ -205,4 +211,20 @@ function rule(context) {
   };
 }
 
-module.exports = rule;
+module.exports = module.exports = {
+  meta: {
+    schema: [
+      {
+        type: 'object',
+        properties: {
+          ignoredFields: {
+            type: 'array',
+            items: {type: 'string'}
+          }
+        },
+        additionalProperties: false
+      }
+    ]
+  },
+  create: rule
+};

test/unused-fields.js

@@ -89,7 +89,16 @@ ruleTester.run('unused-fields', rules['unused-fields'], {
         # eslint-disable-next-line relay/unused-fields
         name
       }\`;
-    `
+    `,
+    {
+      code: `
+        graphql\`fragment foo on Page {
+          edges { node { name } }
+        }\`;
+        getCollectionNodes(foo)[0]?.name;
+      `,
+      options: [{ignoredFields: ['node', 'edges']}]
+    }
   ],
   invalid: [
     {
@@ -163,6 +172,15 @@ ruleTester.run('unused-fields', rules['unused-fields'], {
           line: 4
         }
       ]
+    },
+    {
+      code: `
+        graphql\`fragment foo on Page {
+          edges { node { name } }
+        }\`;
+        getCollectionNodes(foo)[0]?.name;
+      `,
+      errors: [unusedFieldsWarning('edges'), unusedFieldsWarning('node')]
     }
   ]
 });