| // @flow strict |
| |
| import { GraphQLError } from '../../error/GraphQLError'; |
| import { type ASTVisitor } from '../../language/visitor'; |
| |
| import { type ASTValidationContext } from '../ValidationContext'; |
| |
| /** |
| * Unique argument names |
| * |
| * A GraphQL field or directive is only valid if all supplied arguments are |
| * uniquely named. |
| */ |
| export function UniqueArgumentNamesRule( |
| context: ASTValidationContext, |
| ): ASTVisitor { |
| let knownArgNames = Object.create(null); |
| return { |
| Field() { |
| knownArgNames = Object.create(null); |
| }, |
| Directive() { |
| knownArgNames = Object.create(null); |
| }, |
| Argument(node) { |
| const argName = node.name.value; |
| if (knownArgNames[argName]) { |
| context.reportError( |
| new GraphQLError( |
| `There can be only one argument named "${argName}".`, |
| [knownArgNames[argName], node.name], |
| ), |
| ); |
| } else { |
| knownArgNames[argName] = node.name; |
| } |
| return false; |
| }, |
| }; |
| } |