fix: cost-limit ignore only Field Node named __schema (#772)

* fix: cost-limit ignore only Field Node named __schema

* fix: linting

Author: M0ngi

packages/plugins/cost-limit/src/index.ts

@@ -85,7 +85,12 @@ class CostLimitVisitor {
     node: FieldNode | FragmentDefinitionNode | InlineFragmentNode | OperationDefinitionNode | FragmentSpreadNode,
     depth = 0,
   ): number {
-    if (this.config.ignoreIntrospection && 'name' in node && node.name?.value === '__schema') {
+    if (
+      this.config.ignoreIntrospection &&
+      'name' in node &&
+      node.name?.value === '__schema' &&
+      node.kind === Kind.FIELD
+    ) {
       return 0;
     }
 

packages/plugins/cost-limit/test/index.spec.ts

@@ -87,6 +87,68 @@ describe('costLimitPlugin', () => {
     ]);
   });
 
+  it('should limit cost for query named `__schema`', async () => {
+    const testkit = createTestkit(
+      [
+        costLimitPlugin({
+          maxCost: 10,
+          objectCost: 4,
+          scalarCost: 2,
+          depthCostFactor: 2,
+          ignoreIntrospection: true,
+        }),
+      ],
+      schema,
+    );
+    const result = await testkit.execute(`
+    query __schema {
+      books {
+        title
+        author
+      }
+    }
+    `);
+
+    assertSingleExecutionValue(result);
+    expect(result.errors).toBeDefined();
+    expect(result.errors?.map((error) => error.message)).toEqual([
+      'Syntax Error: Query Cost limit of 10 exceeded, found 12.',
+    ]);
+  });
+
+  it('should limit cost for fragment named `__schema`', async () => {
+    const testkit = createTestkit(
+      [
+        costLimitPlugin({
+          maxCost: 10,
+          objectCost: 4,
+          scalarCost: 2,
+          depthCostFactor: 2,
+          ignoreIntrospection: true,
+        }),
+      ],
+      schema,
+    );
+    const result = await testkit.execute(`
+    query  {
+      ...__schema
+    }
+
+    fragment __schema on Query {
+      books {
+        title
+        author
+      }
+    }
+    `);
+
+    assertSingleExecutionValue(result);
+    expect(result.errors).toBeDefined();
+    expect(result.errors?.map((error) => error.message)).toEqual([
+      'Syntax Error: Query Cost limit of 10 exceeded, found 58.',
+    ]);
+  });
+
   it('should allow introspection', async () => {
     const testkit = createTestkit(
       [
@@ -100,6 +162,7 @@ describe('costLimitPlugin', () => {
       ],
       schema,
     );
+    const x = getIntrospectionQuery();
     const result = await testkit.execute(getIntrospectionQuery());
 
     assertSingleExecutionValue(result);