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

shared relay validation rules for graphql-js parser

import {
  ASTNode,
  DirectiveNode,
  FieldNode,
  FragmentDefinitionNode,
  FragmentSpreadNode,
  GraphQLOutputType,
  GraphQLType,
} from "graphql";
import { BREAK, getNullableType, GraphQLNonNull, GraphQLObjectType, visit } from "graphql";

export function findFragmentSpreadParent(nodes: readonly any[]): FragmentSpreadNode | undefined {
  return nodes.find(isFragmentSpread);
}

export function findFragmentDefinitionParent(nodes: readonly any[]): FragmentDefinitionNode | undefined {
  return nodes.find(isFragmentDefinition);
}

export function isFragmentSpread(node: any): node is FragmentSpreadNode {
  return node != null && node.kind === "FragmentSpread";
}

export function isFragmentDefinition(node: any): node is FragmentDefinitionNode {
  return node != null && node.kind === "FragmentDefinition";
}

export function containsVariableNodes(node: ASTNode): boolean {
  let hasVars = false;

  visit(node, {
    Variable() {
      hasVars = true;
      return BREAK;
    },
  });
  return hasVars;
}

export function makeNonNullable(type: GraphQLType): GraphQLType {
  if (!(type instanceof GraphQLNonNull)) {
    return new GraphQLNonNull(type);
  }
  return type;
}

export function getConnectionDirective(fieldNode: FieldNode): { key: string | null; directive: DirectiveNode } | null {
  const directive = fieldNode.directives && fieldNode.directives.find((d) => d.name.value === "connection");

  if (!directive) {
    return null;
  }

  const keyArgument = directive.arguments && directive.arguments.find((arg) => arg.name.value === "key");
  if (!keyArgument || keyArgument.value.kind !== "StringValue") {
    return {
      key: null,
      directive,
    };
  }

  return {
    key: keyArgument.value.value,
    directive,
  };
}

export function isConnectionType(type: GraphQLOutputType): boolean {
  const nullableType = getNullableType(type);

  if (!(nullableType instanceof GraphQLObjectType)) {
    return false;
  }

  return nullableType.name.endsWith("Connection");
}