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import { GraphQLError } from '../../error/GraphQLError.mjs';
/**
* Unique operation types
*
* A GraphQL document is only valid if it has only one type per operation.
*/
export function UniqueOperationTypesRule(context) {
const schema = context.getSchema();
const definedOperationTypes = Object.create(null);
const existingOperationTypes = schema
? {
query: schema.getQueryType(),
mutation: schema.getMutationType(),
subscription: schema.getSubscriptionType(),
}
: {};
return {
SchemaDefinition: checkOperationTypes,
SchemaExtension: checkOperationTypes,
};
function checkOperationTypes(node) {
var _node$operationTypes;
// See: https://github.com/graphql/graphql-js/issues/2203
/* c8 ignore next */
const operationTypesNodes =
(_node$operationTypes = node.operationTypes) !== null &&
_node$operationTypes !== void 0
? _node$operationTypes
: [];
for (const operationType of operationTypesNodes) {
const operation = operationType.operation;
const alreadyDefinedOperationType = definedOperationTypes[operation];
if (existingOperationTypes[operation]) {
context.reportError(
new GraphQLError(
`Type for ${operation} already defined in the schema. It cannot be redefined.`,
{
nodes: operationType,
},
),
);
} else if (alreadyDefinedOperationType) {
context.reportError(
new GraphQLError(
`There can be only one ${operation} type in schema.`,
{
nodes: [alreadyDefinedOperationType, operationType],
},
),
);
} else {
definedOperationTypes[operation] = operationType;
}
}
return false;
}
}