Detox your GraphQL: Mocking Date scalar type example

mockingDate.js

const { GraphQLScalarType } = require("graphql");
const { Kind } = require("graphql/language");

const date = {
  Date: () => new Date()
};

// for custom scalar types such as Date you need to write resolvers
// then add them to ApolloServer config in startGraphQLServer
const resolvers = {
  Date: new GraphQLScalarType({
    name: "Date",
    description: "Date custom scalar type",
    parseValue(value) {
      return new Date(value);
    },
    serialize(value) {
      return value.getTime();
    },
    parseLiteral(ast) {
      if (ast.kind === Kind.INT) {
        return new Date(ast.value);
      }
      return null;
    }
  })
};