| /** @category Validation Rules */ |
| import type { ASTVisitor } from '../../language/visitor'; |
| import type { ASTValidationContext } from '../ValidationContext'; |
| /** |
| * Unique variable names |
| * |
| * A GraphQL operation is only valid if all its variables are uniquely named. |
| * @param context - The validation context used while checking the document. |
| * @returns A visitor that reports validation errors for this rule. |
| * @example |
| * ```ts |
| * import { buildSchema, parse, validate } from 'graphql'; |
| * import { UniqueVariableNamesRule } from 'graphql/validation'; |
| * |
| * const schema = buildSchema(` |
| * type Query { |
| * field(arg: ID): String |
| * } |
| * `); |
| * |
| * const invalidDocument = parse(` |
| * query ($id: ID, $id: ID) { field(arg: $id) } |
| * `); |
| * const invalidErrors = validate(schema, invalidDocument, [UniqueVariableNamesRule]); |
| * |
| * invalidErrors.length; // => 1 |
| * |
| * const validDocument = parse(` |
| * query ($id: ID) { field(arg: $id) } |
| * `); |
| * const validErrors = validate(schema, validDocument, [UniqueVariableNamesRule]); |
| * |
| * validErrors; // => [] |
| * ``` |
| */ |
| export declare function UniqueVariableNamesRule( |
| context: ASTValidationContext, |
| ): ASTVisitor; |