fix schema renderer (#1823)

Was crashing because `enum` type was not supported.

# Test
```
scripts/gen/schema-docs.sh
```

[New generated doc](https://github.com/swarm-game/swarm/blob/ebe28c3a781fded37024fce8d49b4ecb95e1577f/data/scenarios/_doc-fragments/SCHEMA.md#directions) now contains "Directions" enum.

app/doc/Swarm/Doc/Schema/Parse.hs

@@ -11,6 +11,7 @@ module Swarm.Doc.Schema.Parse where
 
 import Control.Applicative ((<|>))
 import Data.Aeson
+import Data.List.NonEmpty (NonEmpty)
 import Data.Map (Map)
 import Data.Maybe (fromMaybe)
 import Data.Text (Text)
@@ -28,6 +29,7 @@ data SchemaData = SchemaData
 data Members
   = ObjectProperties (Map Text SwarmSchema)
   | ListMembers (ItemDescription SwarmSchema)
+  | EnumMembers (NonEmpty Text)
   deriving (Eq, Ord, Show)
 
 data ToplevelSchema = ToplevelSchema
@@ -49,4 +51,5 @@ instance FromJSON ToplevelSchema where
         maybeMembers =
           ObjectProperties <$> properties swarmSchema
             <|> ListMembers <$> itemsDescription swarmSchema
+            <|> EnumMembers <$> _enum rawSchema
     return $ ToplevelSchema theTitle (objectDescription swarmSchema) swarmSchema maybeMembers theFooters

app/doc/Swarm/Doc/Schema/Refined.hs

@@ -11,6 +11,7 @@ module Swarm.Doc.Schema.Refined where
 import Control.Applicative ((<|>))
 import Data.Aeson
 import Data.List.Extra (replace)
+import Data.List.NonEmpty (NonEmpty)
 import Data.Map (Map)
 import Data.Map qualified as M
 import Data.Maybe (fromMaybe, mapMaybe)
@@ -47,6 +48,7 @@ data SchemaRaw = SchemaRaw
   , _oneOf :: Maybe [SchemaRaw]
   , _footers :: Maybe [FilePath]
   , _additionalProperties :: Maybe Bool
+  , _enum :: Maybe (NonEmpty Text)
   }
   deriving (Eq, Ord, Show, Generic)
 
@@ -59,6 +61,7 @@ extractSchemaType rawSchema =
     <|> getTypeFromItems
     <|> Simple <$> _type rawSchema
     <|> Alternatives . mapMaybe extractSchemaType <$> _oneOf rawSchema
+    <|> EnumList <$> _enum rawSchema
  where
   mkReference = Reference . SchemaIdReference . T.pack . takeBaseName . T.unpack
 
@@ -87,6 +90,7 @@ getSchemaReferences = \case
   Alternatives xs -> concatMap getSchemaReferences xs
   Reference x -> pure x
   ListOf x -> getSchemaReferences x
+  EnumList _ -> []
 
 -- | A subset of all JSON schemas, conforming to internal Swarm conventions.
 --

app/doc/Swarm/Doc/Schema/Render.hs

@@ -14,6 +14,7 @@ import Control.Monad.IO.Class (liftIO)
 import Control.Monad.Trans.Except (except)
 import Data.Aeson
 import Data.List (intersperse)
+import Data.List.NonEmpty qualified as NE
 import Data.Map (Map)
 import Data.Map.Strict qualified as M
 import Data.Maybe (fromMaybe)
@@ -81,6 +82,10 @@ makePandocTable titleMap (SchemaData _ (ToplevelSchema theTitle theDescription _
   mkTable x = doc $ case x of
     ObjectProperties props -> makePropsTable True propertyColumnHeadings titleMap props
     ListMembers someStuff -> renderItems someStuff
+    EnumMembers enumMembers ->
+      simpleTable [plain $ text "Member"] $
+        map (\m -> [plain $ code m]) $
+          NE.toList enumMembers
 
 genPropsRow :: Bool -> Map SchemaIdReference T.Text -> (T.Text, SwarmSchema) -> [Blocks]
 genPropsRow includeDefaultColumn titleMap (k, x) =
@@ -176,6 +181,7 @@ listToText titleMap = \case
   Alternatives xs -> renderAlternatives $ map (listToText titleMap) xs
   Reference r@(SchemaIdReference x) -> schemaLink r x
   ListOf x -> listToText titleMap x <> text " list"
+  EnumList xs -> renderAlternatives $ NE.toList $ text <$> xs
  where
   renderAlternatives = mconcat . intersperse (text " or ")
   schemaLink r = link (fragmentHref titleMap r) "Link to object properties" . text

app/doc/Swarm/Doc/Schema/SchemaType.hs

@@ -6,6 +6,7 @@ module Swarm.Doc.Schema.SchemaType where
 
 import Control.Applicative ((<|>))
 import Data.Aeson
+import Data.List.NonEmpty (NonEmpty)
 import Data.Text (Text)
 import Data.Text qualified as T
 import System.FilePath (takeBaseName)
@@ -29,6 +30,7 @@ data SchemaType
     Reference SchemaIdReference
   | -- | Members of a list, all of the given schema type
     ListOf SchemaType
+  | EnumList (NonEmpty Text)
   deriving (Eq, Ord, Show)
 
 newtype SchemaIdReference = SchemaIdReference Text