| /** @category Validation Rules */ |
| import { groupBy } from '../../jsutils/groupBy.mjs'; |
| import { GraphQLError } from '../../error/GraphQLError.mjs'; |
| |
| /** |
| * 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: $id) } |
| * `); |
| * const validErrors = validate(schema, validDocument, [UniqueVariableNamesRule]); |
| * |
| * validErrors; // => [] |
| * ``` |
| */ |
| export function UniqueVariableNamesRule(context) { |
| return { |
| OperationDefinition(operationNode) { |
| var _operationNode$variab; |
| |
| // See: https://github.com/graphql/graphql-js/issues/2203 |
| |
| /* c8 ignore next */ |
| const variableDefinitions = |
| (_operationNode$variab = operationNode.variableDefinitions) !== null && |
| _operationNode$variab !== void 0 |
| ? _operationNode$variab |
| : []; |
| const seenVariableDefinitions = groupBy( |
| variableDefinitions, |
| (node) => node.variable.name.value, |
| ); |
| |
| for (const [variableName, variableNodes] of seenVariableDefinitions) { |
| if (variableNodes.length > 1) { |
| context.reportError( |
| new GraphQLError( |
| `There can be only one variable named "$${variableName}".`, |
| { |
| nodes: variableNodes.map((node) => node.variable.name), |
| }, |
| ), |
| ); |
| } |
| } |
| }, |
| }; |
| } |