| /** @category Validation Rules */ |
| import { invariant } from '../../jsutils/invariant.mjs'; |
| import { GraphQLError } from '../../error/GraphQLError.mjs'; |
| |
| /** |
| * Unique input field names |
| * |
| * A GraphQL input object value is only valid if all supplied fields are |
| * uniquely named. |
| * |
| * See https://spec.graphql.org/draft/#sec-Input-Object-Field-Uniqueness |
| * @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 { UniqueInputFieldNamesRule } from 'graphql/validation'; |
| * |
| * const schema = buildSchema(` |
| * input Filter { |
| * name: String |
| * } |
| * |
| * type Query { |
| * search(filter: Filter): String |
| * } |
| * `); |
| * |
| * const invalidDocument = parse(` |
| * { search(filter: { name: "a", name: "b" }) } |
| * `); |
| * const invalidErrors = validate(schema, invalidDocument, [UniqueInputFieldNamesRule]); |
| * |
| * invalidErrors.length; // => 1 |
| * |
| * const validDocument = parse(` |
| * { search(filter: { name: "a" }) } |
| * `); |
| * const validErrors = validate(schema, validDocument, [UniqueInputFieldNamesRule]); |
| * |
| * validErrors; // => [] |
| * ``` |
| */ |
| export function UniqueInputFieldNamesRule(context) { |
| const knownNameStack = []; |
| let knownNames = Object.create(null); |
| return { |
| ObjectValue: { |
| enter() { |
| knownNameStack.push(knownNames); |
| knownNames = Object.create(null); |
| }, |
| |
| leave() { |
| const prevKnownNames = knownNameStack.pop(); |
| prevKnownNames || invariant(false); |
| knownNames = prevKnownNames; |
| }, |
| }, |
| |
| ObjectField(node) { |
| const fieldName = node.name.value; |
| |
| if (knownNames[fieldName]) { |
| context.reportError( |
| new GraphQLError( |
| `There can be only one input field named "${fieldName}".`, |
| { |
| nodes: [knownNames[fieldName], node.name], |
| }, |
| ), |
| ); |
| } else { |
| knownNames[fieldName] = node.name; |
| } |
| }, |
| }; |
| } |