swc/crates/swc_bundler/tests/.cache/deno/ac2b751ad023e6ef3ede6e8506946a9f3ab9cd3c.ts

// Loaded from https://deno.land/x/graphql_deno@v15.0.0/lib/validation/rules/UniqueFieldDefinitionNamesRule.js


import { GraphQLError } from '../../error/GraphQLError.js';
import { isObjectType, isInterfaceType, isInputObjectType } from '../../type/definition.js';

/**
 * Unique field definition names
 *
 * A GraphQL complex type is only valid if all its fields are uniquely named.
 */
export function UniqueFieldDefinitionNamesRule(context) {
  const schema = context.getSchema();
  const existingTypeMap = schema ? schema.getTypeMap() : Object.create(null);
  const knownFieldNames = Object.create(null);
  return {
    InputObjectTypeDefinition: checkFieldUniqueness,
    InputObjectTypeExtension: checkFieldUniqueness,
    InterfaceTypeDefinition: checkFieldUniqueness,
    InterfaceTypeExtension: checkFieldUniqueness,
    ObjectTypeDefinition: checkFieldUniqueness,
    ObjectTypeExtension: checkFieldUniqueness
  };

  function checkFieldUniqueness(node) {
    const typeName = node.name.value;

    if (!knownFieldNames[typeName]) {
      knownFieldNames[typeName] = Object.create(null);
    }
    /* istanbul ignore next (See https://github.com/graphql/graphql-js/issues/2203) */


    const fieldNodes = node.fields ?? [];
    const fieldNames = knownFieldNames[typeName];

    for (const fieldDef of fieldNodes) {
      const fieldName = fieldDef.name.value;

      if (hasField(existingTypeMap[typeName], fieldName)) {
        context.reportError(new GraphQLError(`Field "${typeName}.${fieldName}" already exists in the schema. It cannot also be defined in this type extension.`, fieldDef.name));
      } else if (fieldNames[fieldName]) {
        context.reportError(new GraphQLError(`Field "${typeName}.${fieldName}" can only be defined once.`, [fieldNames[fieldName], fieldDef.name]));
      } else {
        fieldNames[fieldName] = fieldDef.name;
      }
    }

    return false;
  }
}

function hasField(type, fieldName) {
  if (isObjectType(type) || isInterfaceType(type) || isInputObjectType(type)) {
    return type.getFields()[fieldName];
  }

  return false;
}