Merge pull request #184 from graphql/unique-input-fields

[RFC] Move input field uniqueness validator

Author: leebyron

src/language/__tests__/parser.js

@@ -107,12 +107,6 @@ fragment MissingOn Type
     ).to.throw('Syntax Error GraphQL (1:37) Unexpected $');
   });
 
-  it('duplicate keys in input object is syntax error', () => {
-    expect(
-      () => parse('{ field(arg: { a: 1, a: 2 }) }')
-    ).to.throw('Syntax Error GraphQL (1:22) Duplicate input object field a.');
-  });
-
   it('does not accept fragments named "on"', () => {
     expect(
       () => parse('fragment on on on { on }')

src/language/parser.js

@@ -528,10 +528,9 @@ function parseList(parser, isConst: boolean): ListValue {
 function parseObject(parser, isConst: boolean): ObjectValue {
   var start = parser.token.start;
   expect(parser, TokenKind.BRACE_L);
-  var fieldNames = {};
   var fields = [];
   while (!skip(parser, TokenKind.BRACE_R)) {
-    fields.push(parseObjectField(parser, isConst, fieldNames));
+    fields.push(parseObjectField(parser, isConst));
   }
   return {
     kind: OBJECT,
@@ -543,24 +542,11 @@ function parseObject(parser, isConst: boolean): ObjectValue {
 /**
  * ObjectField[Const] : Name : Value[?Const]
  */
-function parseObjectField(
-  parser,
-  isConst: boolean,
-  fieldNames: {[name: string]: boolean}
-): ObjectField {
+function parseObjectField(parser, isConst: boolean): ObjectField {
   var start = parser.token.start;
-  var name = parseName(parser);
-  if (fieldNames.hasOwnProperty(name.value)) {
-    throw syntaxError(
-      parser.source,
-      start,
-      `Duplicate input object field ${name.value}.`
-    );
-  }
-  fieldNames[name.value] = true;
   return {
     kind: OBJECT_FIELD,
-    name,
+    name: parseName(parser),
     value:
       (expect(parser, TokenKind.COLON), parseValueLiteral(parser, isConst)),
     loc: loc(parser, start)

src/validation/__tests__/UniqueInputFieldNames.js

@@ -0,0 +1,72 @@
+/**
+ *  Copyright (c) 2015, Facebook, Inc.
+ *  All rights reserved.
+ *
+ *  This source code is licensed under the BSD-style license found in the
+ *  LICENSE file in the root directory of this source tree. An additional grant
+ *  of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+import { describe, it } from 'mocha';
+import { expectPassesRule, expectFailsRule } from './harness';
+import {
+  UniqueInputFieldNames,
+  duplicateInputFieldMessage,
+} from '../rules/UniqueInputFieldNames';
+
+
+function duplicateField(name, l1, c1, l2, c2) {
+  return {
+    message: duplicateInputFieldMessage(name),
+    locations: [ { line: l1, column: c1 }, { line: l2, column: c2 } ],
+  };
+}
+
+describe('Validate: Unique input field names', () => {
+
+  it('input object with fields', () => {
+    expectPassesRule(UniqueInputFieldNames, `
+      {
+        field(arg: { f: true })
+      }
+    `);
+  });
+
+  it('same input object within two args', () => {
+    expectPassesRule(UniqueInputFieldNames, `
+      {
+        field(arg1: { f: true }, arg2: { f: true })
+      }
+    `);
+  });
+
+  it('multiple input object fields', () => {
+    expectPassesRule(UniqueInputFieldNames, `
+      {
+        field(arg: { f1: "value", f2: "value", f3: "value" })
+      }
+    `);
+  });
+
+  it('duplicate input object fields', () => {
+    expectFailsRule(UniqueInputFieldNames, `
+      {
+        field(arg: { f1: "value", f1: "value" })
+      }
+    `, [
+      duplicateField('f1', 3, 22, 3, 35)
+    ]);
+  });
+
+  it('many duplicate input object fields', () => {
+    expectFailsRule(UniqueInputFieldNames, `
+      {
+        field(arg: { f1: "value", f1: "value", f1: "value" })
+      }
+    `, [
+      duplicateField('f1', 3, 22, 3, 35),
+      duplicateField('f1', 3, 22, 3, 48)
+    ]);
+  });
+
+});

src/validation/rules/UniqueInputFieldNames.js

@@ -0,0 +1,41 @@
+/* @flow */
+/**
+ *  Copyright (c) 2015, Facebook, Inc.
+ *  All rights reserved.
+ *
+ *  This source code is licensed under the BSD-style license found in the
+ *  LICENSE file in the root directory of this source tree. An additional grant
+ *  of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+import { GraphQLError } from '../../error';
+
+
+export function duplicateInputFieldMessage(fieldName: any): string {
+  return `There can be only one input field named "${fieldName}".`;
+}
+
+/**
+ * Unique input field names
+ *
+ * A GraphQL input object value is only valid if all supplied fields are
+ * uniquely named.
+ */
+export function UniqueInputFieldNames(): any {
+  var knownNames = Object.create(null);
+  return {
+    ObjectValue() {
+      knownNames = Object.create(null);
+    },
+    ObjectField(node) {
+      var fieldName = node.name.value;
+      if (knownNames[fieldName]) {
+        return new GraphQLError(
+          duplicateInputFieldMessage(fieldName),
+          [ knownNames[fieldName], node.name ]
+        );
+      }
+      knownNames[fieldName] = node.name;
+    }
+  };
+}

src/validation/specifiedRules.js

@@ -76,6 +76,9 @@ import {
   OverlappingFieldsCanBeMerged
 } from './rules/OverlappingFieldsCanBeMerged';
 
+// Spec Section: "Input Object Field Uniqueness"
+import { UniqueInputFieldNames } from './rules/UniqueInputFieldNames';
+
 
 /**
  * This set includes all validation rules defined by the GraphQL spec.
@@ -103,4 +106,5 @@ export var specifiedRules = [
   DefaultValuesOfCorrectType,
   VariablesInAllowedPosition,
   OverlappingFieldsCanBeMerged,
+  UniqueInputFieldNames,
 ];