GraphQL Union Types and GraphQL Tools

Learn how to define a GraphQL Union Type using GraphQL Tools.

Notes

const typeDefs = `
type Query {
tracks: [Track]
videos: [Video]
images: [Image]
feed: [FeedItem!]!
}
union FeedItem = Track | Video | Image
type Track {
duration: Int
format: TrackFormat
}
type Video {
length: Int
format: VideoFormat
}
type Image {
width: Int
height: Int
format: ImageFormat
}
enum TrackFormat {
WAV
MP3
AAC
}
enum VideoFormat {
AVI
MP4
M4V
}
enum ImageFormat {
PNG
JPG
TIFF
}
`;
const resolvers = {
Query: {
tracks: () => tracks,
videos: () => videos,
images: () => images,
feed: () => [
...tracks,
...videos,
...images,
{
width: 500,
height: 350,
format: "TIFF",
},
],
},
FeedItem: {
__resolveType: (object) => {
if (object.duration) {
return "Track";
}
if (object.length) {
return "Video";
}
if (object.width) {
return "Image";
}
return null;
},
},
};
Jamie Barton

Published on 22 Nov 2021 by Jamie Barton