Example Caliban app for the talk

Slides can be found here

In this application you can create users, repos and forks and also import them from Github.

Running application

Application is in graphql package. To start server

• have docker installed
• run graphql.CalibanApp
• open http://localhost:8088/graphiql

If you want to run it against local postgres

• go to CalibanApp and setup customLayer
• setup db in application.conf or overwrite it env.conf

If you enable authorization in graphql.package.resolver and you can test it by inputting token to top right corner in graphiql e.g. {"name": "String", "roles": ["VIEWER"]}

Libraries used:

• caliban - graphql server
• caliban-client - graphql client
• zio - effect
• http4s - web server
• circe - json
• doobie and quill - database
• sttp - http client
• shapeless - just for type tags
• testcontainers-scala - postgresql in docker container in tests
• flyway - migrations

GraphQL tests

Tests are written in markdown files. Single file represent single request. One directory is a test suite. Requests/files are executes sequentially ordered by file names. To create test you need only extend GQLTestBase as it is done in UserTest. You can store values to cache between requests by using <<< and read them by using <<< as you can see in 01_create-user.md. Stored value might be any json, not just string. String is used only as a placeholder.

Example package

Example package contains examples shown in the talk which were not part of our application:

• GithubQuery - standalone example showing how to call Github graphql api with the help of caliban-client
• MagnoliaExample - Magnolia simple use case - used in Caliban for typeclass derivations
• SlideExamples - examples which were on the slides
• ZIOFirstExample - simple ZIO app
• ZIOTypeInference - example how type inference works in ZIO

GithubApi.scala

Client was generated via

calibanGenClient src/main/resources/schema.docs.graphql src/main/scala/graphql/GithubApi.scala