test for lone-schema-definition rule (#407)

* feat: add tests for `lone-schema-definition` rule

* Fix lone-schema-definition

* update rule docs

Co-authored-by: dimitri <[email protected]>
Co-authored-by: Dotan Simha <[email protected]>

Author: 3 people

.changeset/ninety-deers-end.md

@@ -0,0 +1,5 @@
+---
+'@graphql-eslint/eslint-plugin': patch
+---
+
+Fix issues with `lone-schema-definition` rule

docs/rules/lone-schema-definition.md

@@ -2,7 +2,7 @@
 
 - Category: `Validation`
 - Rule name: `@graphql-eslint/lone-schema-definition`
-- Requires GraphQL Schema: `true` [ℹ️](../../README.md#extended-linting-rules-with-graphql-schema)
+- 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)
 
 A GraphQL document is only valid if it contains only one schema definition.

packages/plugin/src/rules/graphql-js-validation.ts

@@ -99,11 +99,16 @@ export const GRAPHQL_JS_VALIDATIONS = Object.assign(
       description: `A GraphQL document is only valid if when it contains an anonymous operation (the query short-hand) that it contains only that one operation definition.`,
     },
   }),
-  validationToRule('lone-schema-definition', 'LoneSchemaDefinition', {
-    docs: {
-      description: `A GraphQL document is only valid if it contains only one schema definition.`,
+  validationToRule(
+    'lone-schema-definition',
+    'LoneSchemaDefinition',
+    {
+      docs: {
+        description: `A GraphQL document is only valid if it contains only one schema definition.`,
+      },
     },
-  }),
+    true
+  ),
   validationToRule('no-fragment-cycles', 'NoFragmentCycles', {
     docs: {
       description: `A GraphQL fragment is only valid when it does not have cycles in fragments usage.`,

packages/plugin/tests/lone-schema-definition.spec.ts

@@ -0,0 +1,66 @@
+import { GraphQLRuleTester } from '../src/testkit';
+import { GRAPHQL_JS_VALIDATIONS } from '../src/rules/graphql-js-validation';
+import { ParserOptions } from '../src/types';
+
+const TEST_SCHEMA = /* GraphQL */`
+  type Query {
+    foo: String
+  }
+
+  type Mutation {
+    bar: Boolean
+  }
+
+  schema {
+    query: Query
+    mutation: Mutation
+  }
+`;
+
+const WITH_SCHEMA = {
+  parserOptions: <ParserOptions>{
+    schema: TEST_SCHEMA,
+    operations: [],
+  },
+};
+
+const ruleTester = new GraphQLRuleTester();
+
+ruleTester.runGraphQLTests('lone-schema-definition', GRAPHQL_JS_VALIDATIONS['lone-schema-definition'], {
+  valid: [{ ...WITH_SCHEMA, code: TEST_SCHEMA }],
+  invalid: [
+    {
+      ...WITH_SCHEMA,
+      code: /* GraphQL */`
+        type Query {
+          foo: String
+        }
+
+        type Mutation {
+          bar: Boolean
+        }
+
+        schema {
+          query: Query
+          mutation: Mutation
+        }
+
+        type RootQuery {
+          foo: String
+        }
+
+        type RootMutation {
+          bar: Boolean
+        }
+
+        schema {
+          query: RootQuery
+          mutation: RootMutation
+        }
+      `,
+      errors: [
+        { message: 'Must provide only one schema definition.' },
+      ],
+    },
+  ],
+});