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

shared relay validation rules for graphql-js parser

import { GraphQLError, valueFromAST } from "graphql";
import type { ValidationRule } from "graphql";

import { getFragmentArgumentDefinitions } from "./argumentDefinitions";
import { containsVariableNodes, findFragmentSpreadParent } from "./utils";

// tslint:disable-next-line: no-shadowed-variable
export const RelayArgumentsOfCorrectType: ValidationRule = function RelayArgumentsOfCorrectType(context) {
  return {
    Directive(directive, _key, _parent, _path, ancestors) {
      if (directive.name.value !== "arguments" || !directive.arguments) {
        return false;
      }
      const fragmentSpread = findFragmentSpreadParent(ancestors);
      if (!fragmentSpread) {
        return false;
      }
      const fragmentDefinition = context.getFragment(fragmentSpread.name.value);
      if (!fragmentDefinition) {
        return false;
      }

      const typedArguments = getFragmentArgumentDefinitions(context, fragmentDefinition);

      directive.arguments.forEach((arg) => {
        const argDef = typedArguments[arg.name.value];
        if (!argDef || !argDef.schemaType) {
          return;
        }

        const schemaType = argDef.schemaType;

        if (containsVariableNodes(arg.value)) {
          return;
        }

        const value = valueFromAST(arg.value, schemaType);

        if (value === undefined) {
          context.reportError(
            new GraphQLError(
              badValueMessage(fragmentDefinition.name.value, arg.name.value, schemaType.toString()),
              arg.value
            )
          );
        }
      });
    },
  };
};

function badValueMessage(fragmentName: string, argName: string, argType: string): string {
  return `Argument "${argName}" for fragment "${fragmentName}" is expected to be of type "${argType}".`;
}