add new rule require-nullable-fields-with-oneof (#1330)

Author: dimaMachina

.changeset/early-geckos-search.md

@@ -0,0 +1,5 @@
+---
+'@graphql-eslint/eslint-plugin': minor
+---
+
+add new rule `require-nullable-fields-with-oneof`

docs/README.md

@@ -58,6 +58,7 @@ Name            &nbs
 [require-description](rules/require-description.md)|Enforce descriptions in type definitions and operations.|![recommended][]|📄|🚀|
 [require-field-of-type-query-in-mutation-result](rules/require-field-of-type-query-in-mutation-result.md)|Allow the client in one round-trip not only to call mutation but also to get a wagon of data to update their application.|![all][]|📄|🚀|
 [require-id-when-available](rules/require-id-when-available.md)|Enforce selecting specific fields when they are available on the GraphQL type.|![recommended][]|📦|🚀|💡
+[require-nullable-fields-with-oneof](rules/require-nullable-fields-with-oneof.md)|Require are `input` or `type` fields be non nullable with `@oneOf` directive.|![all][]|📄|🚀|
 [scalar-leafs](rules/scalar-leafs.md)|A GraphQL document is valid only if all leaf fields (fields without sub selections) are of scalar or enum types.|![recommended][]|📦|🔮|💡
 [selection-set-depth](rules/selection-set-depth.md)|Limit the complexity of the GraphQL operations solely by their depth. Based on [graphql-depth-limit](https://npmjs.com/package/graphql-depth-limit).|![recommended][]|📦|🚀|💡
 [strict-id-in-types](rules/strict-id-in-types.md)|Requires output types to have one unique identifier unless they do not have a logical one. Exceptions can be used to ignore output types that do not have unique identifiers.|![recommended][]|📄|🚀|

docs/rules/require-nullable-fields-with-oneof.md

@@ -0,0 +1,38 @@
+# `require-nullable-fields-with-oneof`
+
+- Category: `Schema`
+- Rule name: `@graphql-eslint/require-nullable-fields-with-oneof`
+- Requires GraphQL Schema: `false` [ℹ️](../../README.md#extended-linting-rules-with-graphql-schema)
+- Requires GraphQL Operations: `false`
+  [ℹ️](../../README.md#extended-linting-rules-with-siblings-operations)
+
+Require are `input` or `type` fields be non nullable with `@oneOf` directive.
+
+## Usage Examples
+
+### Incorrect
+
+```graphql
+# eslint @graphql-eslint/require-nullable-fields-with-oneof: 'error'
+
+input Input @oneOf {
+  foo: String!
+  b: Int
+}
+```
+
+### Correct
+
+```graphql
+# eslint @graphql-eslint/require-nullable-fields-with-oneof: 'error'
+
+input Input @oneOf {
+  foo: String
+  bar: Int
+}
+```
+
+## Resources
+
+- [Rule source](../../packages/plugin/src/rules/require-nullable-fields-with-oneof.ts)
+- [Test source](../../packages/plugin/tests/require-nullable-fields-with-oneof.spec.ts)

package.json

@@ -28,7 +28,7 @@
     "@types/node": "18.11.17",
     "@typescript-eslint/eslint-plugin": "5.47.0",
     "@typescript-eslint/parser": "5.47.0",
-    "bob-the-bundler": "4.2.0-alpha-20221222123652-a454f30",
+    "bob-the-bundler": "4.2.0-alpha-20221222140753-fcf5286",
     "chalk": "^4.1.2",
     "dedent": "0.7.0",
     "enquirer": "2.3.6",

packages/plugin/src/configs/schema-all.ts

@@ -17,5 +17,6 @@ export default {
     '@graphql-eslint/no-scalar-result-type-on-mutation': 'error',
     '@graphql-eslint/require-deprecation-date': 'error',
     '@graphql-eslint/require-field-of-type-query-in-mutation-result': 'error',
+    '@graphql-eslint/require-nullable-fields-with-oneof': 'error',
   },
 };

packages/plugin/src/rules/index.ts

@@ -28,6 +28,7 @@ import { rule as requireDeprecationReason } from './require-deprecation-reason';
 import { rule as requireDescription } from './require-description';
 import { rule as requireFieldOfTypeQueryInMutationResult } from './require-field-of-type-query-in-mutation-result';
 import { rule as requireIdWhenAvailable } from './require-id-when-available';
+import { rule as requireNullableFieldsWithOneof } from './require-nullable-fields-with-oneof';
 import { rule as selectionSetDepth } from './selection-set-depth';
 import { rule as strictIdInTypes } from './strict-id-in-types';
 import { rule as uniqueFragmentName } from './unique-fragment-name';
@@ -60,6 +61,7 @@ export const rules = {
   'require-description': requireDescription,
   'require-field-of-type-query-in-mutation-result': requireFieldOfTypeQueryInMutationResult,
   'require-id-when-available': requireIdWhenAvailable,
+  'require-nullable-fields-with-oneof': requireNullableFieldsWithOneof,
   'selection-set-depth': selectionSetDepth,
   'strict-id-in-types': strictIdInTypes,
   'unique-fragment-name': uniqueFragmentName,

packages/plugin/src/rules/require-nullable-fields-with-oneof.ts

@@ -0,0 +1,64 @@
+import { GraphQLESLintRule } from '../types';
+import { InputObjectTypeDefinitionNode, Kind, ObjectTypeDefinitionNode } from 'graphql';
+import { GraphQLESTreeNode } from '../estree-converter';
+
+const RULE_ID = 'require-nullable-fields-with-oneof';
+
+export const rule: GraphQLESLintRule = {
+  meta: {
+    type: 'suggestion',
+    docs: {
+      category: 'Schema',
+      description: 'Require are `input` or `type` fields be non nullable with `@oneOf` directive.',
+      url: `https://github.com/B2o5T/graphql-eslint/blob/master/docs/rules/${RULE_ID}.md`,
+      examples: [
+        {
+          title: 'Incorrect',
+          code: /* GraphQL */ `
+            input Input @oneOf {
+              foo: String!
+              b: Int
+            }
+          `,
+        },
+        {
+          title: 'Correct',
+          code: /* GraphQL */ `
+            input Input @oneOf {
+              foo: String
+              bar: Int
+            }
+          `,
+        },
+      ],
+    },
+    messages: {
+      [RULE_ID]: 'Field `{{fieldName}}` must be nullable.',
+    },
+    schema: [],
+  },
+  create(context) {
+    return {
+      'Directive[name.value=oneOf]'(node: {
+        parent: GraphQLESTreeNode<InputObjectTypeDefinitionNode | ObjectTypeDefinitionNode>;
+      }) {
+        const isTypeOrInput = [
+          Kind.OBJECT_TYPE_DEFINITION,
+          Kind.INPUT_OBJECT_TYPE_DEFINITION,
+        ].includes(node.parent.kind);
+        if (!isTypeOrInput) {
+          return;
+        }
+        for (const field of node.parent.fields) {
+          if (field.gqlType.kind === Kind.NON_NULL_TYPE) {
+            context.report({
+              node: field.name,
+              messageId: RULE_ID,
+              data: { fieldName: field.name.value },
+            });
+          }
+        }
+      },
+    };
+  },
+};

packages/plugin/tests/__snapshots__/require-nullable-fields-with-oneof.spec.md

@@ -0,0 +1,40 @@
+// Vitest Snapshot v1
+
+exports[`should validate \`input\` 1`] = `
+#### ⌨️ Code
+
+      1 |         input Input @oneOf {
+      2 |           foo: String!
+      3 |           bar: [Int]!
+      4 |         }
+
+#### ❌ Error 1/2
+
+      1 |         input Input @oneOf {
+    > 2 |           foo: String!
+        |           ^^^ Field \`foo\` must be nullable.
+      3 |           bar: [Int]!
+
+#### ❌ Error 2/2
+
+      2 |           foo: String!
+    > 3 |           bar: [Int]!
+        |           ^^^ Field \`bar\` must be nullable.
+      4 |         }
+`;
+
+exports[`should validate \`type\` 1`] = `
+#### ⌨️ Code
+
+      1 |         type Type @oneOf {
+      2 |           foo: String!
+      3 |           bar: Int
+      4 |         }
+
+#### ❌ Error
+
+      1 |         type Type @oneOf {
+    > 2 |           foo: String!
+        |           ^^^ Field \`foo\` must be nullable.
+      3 |           bar: Int
+`;

packages/plugin/tests/require-nullable-fields-with-oneof.spec.ts

@@ -0,0 +1,46 @@
+import { GraphQLRuleTester } from '../src';
+import { rule } from '../src/rules/require-nullable-fields-with-oneof';
+
+const ruleTester = new GraphQLRuleTester();
+
+ruleTester.runGraphQLTests('require-nullable-fields-with-oneof', rule, {
+  valid: [
+    /* GraphQL */ `
+      input Input @oneOf {
+        foo: [String]
+        bar: Int
+      }
+    `,
+    /* GraphQL */ `
+      type User @oneOf {
+        foo: String
+        bar: [Int!]
+      }
+    `,
+  ],
+  invalid: [
+    {
+      name: 'should validate `input`',
+      code: /* GraphQL */ `
+        input Input @oneOf {
+          foo: String!
+          bar: [Int]!
+        }
+      `,
+      errors: [
+        { message: 'Field `foo` must be nullable.' },
+        { message: 'Field `bar` must be nullable.' },
+      ],
+    },
+    {
+      name: 'should validate `type`',
+      code: /* GraphQL */ `
+        type Type @oneOf {
+          foo: String!
+          bar: Int
+        }
+      `,
+      errors: [{ message: 'Field `foo` must be nullable.' }],
+    },
+  ],
+});