Validate Input Objects do not contain non-nullable circu…

src/validation/__tests__/InputObjectCircularReferences-test.js

@@ -0,0 +1,80 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import { describe, it } from 'mocha';
+import { expectPassesRule, expectFailsRule } from './harness';
+import {
+  InputObjectCircularReferences,
+  unbrokenCircularReferenceMessage,
+} from '../rules/InputObjectCircularReferences';
+
+function unbrokenCircularReference(defName, fieldName, line, column) {
+  return {
+    message: unbrokenCircularReferenceMessage(defName, fieldName),
+    locations: [{ line, column }],
+  };
+}
+
+describe('Validate: Executable definitions', () => {
+  it('Allow simple input object with nullable circular reference', () => {
+    expectPassesRule(
+      InputObjectCircularReferences,
+      `
+      input Example {
+        self: Example
+        value: String
+      }
+    `,
+    );
+  });
+
+  it('Allow input object with circular reference broken up by a list', () => {
+    expectPassesRule(
+      InputObjectCircularReferences,
+      `
+      input Example {
+        self: [Example!]!
+        value: String
+      }
+    `,
+    );
+  });
+
+  it('Reject simple input object with non-nullable circular reference', () => {
+    expectFailsRule(
+      InputObjectCircularReferences,
+      `
+      input Example {
+        value: String
+        self: Example!
+      }
+    `,
+      [unbrokenCircularReference('Example', 'self', 3, 8)],
+    );
+  });
+
+  it('Reject input object with non-nullable circular reference spread across multiple inputs', () => {
+    expectFailsRule(
+      InputObjectCircularReferences,
+      `
+      input First {
+        second: Second!
+        value: String
+      }
+
+      input Second {
+        first: First!
+        value: String
+      }
+    `,
+      [
+        unbrokenCircularReference('First', 'second', 3, 8),
+        unbrokenCircularReference('Second', 'first', 8, 8),
+      ],
+    );
+  });
+});