graphql-engine/server/src-lib/Hasura/Metadata/DTO/MetadataV1.hs
Jesse Hallett 2f3ae93ab0 server: initial set of DTO types for metadata
This implements an initial set of DTO types that represent serialized metadata. These new types come with codecs using autodocodec which are used to derive both JSON serialization, and OpenAPI documentation. This ensures that we can automatically generate API documentation that is guaranteed to match JSON produced by the server.

For the moment the new types are not used for anything except to generate an early version of an OpenAPI document. Because this is early work the DTO types for each metadata format version list top-level properties only with placeholders for the types of each top-level property. This early iteration demonstrates using a sum type in Haskell that maps to a tagged union in OpenAPI (using the `version` field value as a tag).

This work is experimental and incomplete! Please do not incorporate the generated OpenAPI documentation into essential workflows at this time.

PR-URL: https://github.com/hasura/graphql-engine-mono/pull/4801
GitOrigin-RevId: d2f110a6237b73520cdba24667333ef14e8cdd3d
2022-06-27 16:33:31 +00:00

30 lines
1.3 KiB
Haskell

module Hasura.Metadata.DTO.MetadataV1 (MetadataV1 (..)) where
import Autodocodec (Autodocodec (Autodocodec), HasCodec (codec), object, optionalField, requiredField, (.=))
import Autodocodec.OpenAPI ()
import Data.Aeson (FromJSON, ToJSON)
import Data.OpenApi qualified as OpenApi
import Hasura.Metadata.DTO.Placeholder (PlaceholderArray)
import Hasura.Metadata.DTO.Utils (optionalVersionField)
import Hasura.Prelude
-- | Revision 1 of the Metadata export format. Note that values of the types,
-- 'PlaceholderArray' and 'PlaceholderObject' are placeholders that will
-- eventually be expanded to represent more detail.
data MetadataV1 = MetadataV1
{ metaV1Functions :: Maybe PlaceholderArray,
metaV1RemoteSchemas :: Maybe PlaceholderArray,
metaV1Tables :: PlaceholderArray
}
deriving stock (Show, Eq, Generic)
deriving (FromJSON, ToJSON, OpenApi.ToSchema) via (Autodocodec MetadataV1)
instance HasCodec MetadataV1 where
codec =
object "MetadataV1" $
MetadataV1
<$ optionalVersionField 1
<*> optionalField "functions" "user-defined SQL functions" .= metaV1Functions
<*> optionalField "remote_schemas" "merge remote GraphQL schemas and provide a unified GraphQL API" .= metaV1RemoteSchemas
<*> requiredField "tables" "configured database tables" .= metaV1Tables