graphql-extend-input
Extend graphql Inputs.
Why?
The Simple answer is, extend input MyInput
is not part of the GraphQL specs.
So, let's say you need to add specific fields to an Input
on a remote fetched schema. In this case, you'll have to actually rewrite whole input schema, so now we have this duplication and it's really hard to maintain. This happens quite often if you are to build a graphql gateway and you need to merge the schemas from graphql microservices. Bonus feature extend enum
also available.
Hopefully this will be introduced into the specs sooner or later!
What's the goal?
- Get the statement
extend input MyInput
andNewInput extend input MyInput
to work. - Don't touch on the AST or GraphQL objects directly, this should work on top of the work already done by other contributors so let's try to make it simple, even if that means fewer features.
- Use
graphql/utilities
as much as possible.
How to use
[NewName] extend <input|enum> ObjectToExt[, AnotherObjectToExt, ...]
- A complex example would be:
NewInput extends input MyInput1, MyInput2, MyInput3 {}
. This will only return text (GraphQL language) with a newinput
type calledNewInput
.
Install
npm i graphql-extend-input --save-prod
Getting partial changes/creations
; // Schema representing a remote fetched schema// this can either be a string or a GraphQLSchema objectconst remoteFetchedSchema = ` scalar Date input BookInput { title: String! date: Date } type Book { id: ID! title: String author: String price: Float } type Query { getBooks(filter: [BookInput]!): Book }`; const newSchema = ;console;/** Output: input BookInput { author: String price: Float title: String! date: Date }*/
So you can now use newSchema
and merge it with remoteFetchedSchema
. It would look something like:
; const mergedSchemas = ;
Input
Extending and creating a new If you don't need to mess with existing Inputs
you could also do the following.
const newSchema = ; console;/** Output: input NewBookInput { author: String price: Float title: String! date: Date } extend type Query { newGetBooks(filter: [NewBookInput]!): Book }*/
Get the complete resulting schema
const newSchema = ; // just need to pass true on the last param console;/** Output: scalar Date input BookInput { author: String price: Float title: String! date: Date } type Book { id: ID! title: String author: String price: Float } type Query { getBooks(filter: [BookInput]!): Book } */
Multiple extends - similar to union
const remoteFetchedSchema = ` input PersonInput { firstname: String! lastname: String! } input AddressBookInput { street: String! phone: String! }`; const newSchema = ; console;/** Output: input EmployeeInput { salary: Float! department: String! street: String! phone: String! firstname: String! lastname: String! } extend type Query { getEmployNumber(input: EmployeeInput): Int! } */
extend enum
Into the wild plus const remoteFetchedSchema = ` input TVShowInput { title: String! duration: Int! } input TVShowCastInput { castMemberName: String! } enum TVShows { lost walking_dead } enum BestTVShows { got breaking_bad black_mirror mr_robot }`; const newSchema = ; console;/** Output: input TVShowSearchInput { tvshow: AllTVShowsEnum castMemberName: String! title: String! duration: Int! } enum AllTVShowsEnum { got breaking_bad black_mirror mr_robot lost walking_dead } type TvShow { title: String! duration: Int! cast: [String!]! } extend type Query { searchTVShows(input: TVShowSearchInput): [TVShow] getTVShow(input: AllTVShowsEnum) TVShow }*/
Work in progress
- Maybe support
extend enum
also or maybe that will be for another repo. ✔️ - More real world examples and tests.
Important note:
Unfortunately I don't do open-source for a living, not that I would mind :), so if you find a bug or have any suggestion to improve this module you're very welcome to contribute.