@relay-graphql-js/validation-rules/src/RelayCompatMissingConnectionDirective.ts

shared relay validation rules for graphql-js parser

import { FieldNode, ValidationRule } from "graphql";
import { GraphQLError } from "graphql";
import { getConnectionDirective, isConnectionType } from "./utils";

function hasAfterArgument(fieldNode: FieldNode): boolean {
  return !!(fieldNode.arguments && fieldNode.arguments.find((arg) => arg.name.value === "after"));
}

function hasBeforeArgument(fieldNode: FieldNode): boolean {
  return !!(fieldNode.arguments && fieldNode.arguments.find((arg) => arg.name.value === "before"));
}

// tslint:disable-next-line: no-shadowed-variable
export const RelayCompatMissingConnectionDirective: ValidationRule = function RelayCompatMissingConnectionDirective(
  context
) {
  return {
    Field: {
      enter(fieldNode) {
        if (!fieldNode.selectionSet) {
          return;
        }
        const type = context.getType();
        if (!type || !isConnectionType(type)) {
          return;
        }
        const connectionDirective = getConnectionDirective(fieldNode);
        if (!connectionDirective && (hasAfterArgument(fieldNode) || hasBeforeArgument(fieldNode))) {
          context.reportError(new GraphQLError("Missing @connection directive", fieldNode));
        }
      },
    },
  };
};