GraphQL Scalars 1.0 is out!

This article was published on Thursday, August 8, 2019 by Arda Tanrikulu @ The Guild Blog

The GraphQL Specification has theInt, Float, String, Booleanand ID Scalar types by
default. Those scalar types help you identify the data and validate it before transferring it
between client and server. But you might need more specific scalars for your GraphQL application, to
help you better describe and validate your app's data.

Validation Using Scalars

For example, you have a String field, but you need to validate upcoming or ongoing string data
using regular expressions. So you should have this validation on each end; one in the client, the
other one in the server and maybe there is another on a source. Instead of duplicating the same
logic in different parts of the project, you can use EmailAddress scalar type that does the
validation inside GraphQL for you.

Serialization and Parsing

The other benefit of using GraphQL scalar types is parsing and serializing while transferring data.
For example, you have DateTime data, but it is transferred as String due to restrictions of
JSON, and each time you receive and pass the data, you have to parse the string and create a
JavaScript Date instance while also serializing it to string before passing it to the client.
Instead of having that logic in your implementation, you can just use DateTime scalar and you
would work with native JavaScriptDate instances directly like it is one of primitive types such as
string, number and boolean.

What's New?

We've recently taken over the maintenance of
GraphQL-Scalars library from the amazing team of OK-Grow!

Since then, we completely rewrote the library using TypeScript, upgraded all dependencies, closed
all the issues and PRs and increased the number of scalars in the package with new scalars like:
BigInt(Long) , GUID , HexColorCode , Hexadecimal , IPv4 , IPv6 , ISBN , MAC , JSON
and more. You can see all scalars in the
README.

Mocking

Apollo Server provides mocks built-in scalars such as Int , String , Float , ID and
Boolean . What if you need same thing for our scalars? So, we provide you mocking functions for
each scalar in this package. You can add those easily in your server for mocking the schema.

import { ApolloServer } from 'apollo-server'
// import all scalars and resolvers
import { mocks, resolvers, typeDefs } from 'graphql-scalars'
import { makeExecutableSchema } from 'graphql-tools'

// Alternatively, import individual scalars and resolvers
// import { DateTimeResolver, DateTimeTypeDefinition, DateTimeMock, ... } from "graphql-scalars"

const server = new ApolloServer({
  typeDefs: [
    // use spread syntax to add scalar definitions to your schema
    ...typeDefs
    // DateTimeDefinition,
    // ...
    // ... other type definitions ...
  ],
  resolvers: {
    // use spread syntax to add scalar resolvers to your resolver map
    ...resolvers
    // DateTimeResolver,
    // ...
    // ... remainder of resolver map ...
  },
  mocks: {
    // use spread syntax to add scalar resolvers to your resolver map
    ...mocks
    // DateTimeMock,
    // ...
    // ... other mocks ...
  }
})

Special Thanks

Thanks to OK-Grow for creating this package,
adriano-di-giovanni for being generous and giving us the
graphql-scalars name on npm, to
Saeris for letting us take other scalar implementations from his fork,
stems for their
graphql-bigint package,
abhiaiyer91 for his
graphql-currency-scalars package and
taion for his
graphql-type-json.