Remove Unique from Definition

GraphQL types can refer to each other in a circular way. The PDV framework used to use values of type `Unique` to recognize two fragments of GraphQL schema as being the same instance. Internally, this is based on `Data.Unique` from the `base` package, which simply increases a counter on every creation of a `Unique` object.

**NB**: The `Unique` values are _not_ used for knot tying the schema combinators themselves (i.e. `Parser`s). The knot tying for `Parser`s is purely based on keys provided to `memoizeOn`. The `Unique` values are _only_ used to recognize two pieces of GraphQL _schema_ as being identical. Originally, the idea was that this would help us with a perfectly correct identification of GraphQL types. But this fully correct equality checking of GraphQL types was never implemented, and does not seem to be necessary to prevent bugs.

Specifically, these `Unique` values are stored as part of `data Definition a`, which specifies a part of our internal abstract syntax tree for the GraphQL types that we expose. The `Unique` values get initialized by the `SchemaT` effect.

In #2894 and #2895, we are experimenting with how (parts of) the GraphQL types can be hidden behind certain permission predicates. This would allow a single GraphQL schema in memory to serve all roles, implementing #2711. The permission predicates get evaluated at query parsing time when we know what role is doing a certain request, thus outputting the correct GraphQL types for that role.

If the approach of #2895 is followed, then the `Definition` objects, and thus the `Unique` values, would be hidden behind the permission predicates. Since the permission predicates are evaluated only after the schema is already supposed to be built, this means that the permission predicates would prevent us from initializing the `Unique` values, rendering them useless.

The simplest remedy to this is to remove our usage of `Unique` altogether from the GraphQL schema and schema combinators. It doesn't serve a functional purpose, doesn't prevent bugs, and requires extra bookkeeping.

PR-URL: https://github.com/hasura/graphql-engine-mono/pull/2980
GitOrigin-RevId: 50d3f9e0b9fbf578ac49c8fc773ba64a94b1f43d

server/documentation/schema.md

@@ -261,7 +261,7 @@ float = Parser
         v                         -> typeMismatch floatScalar "a float" v
   }
   where
-    schemaType = NonNullable $ TNamed $ mkDefinition "Float" Nothing TIScalar
+    schemaType = NonNullable $ TNamed $ Definition "Float" Nothing TIScalar
 ```
 
 This allows us to incrementally unpack JSON values without having to fully

server/src-lib/Hasura/App.hs

@@ -52,7 +52,6 @@ import Control.Monad.STM (atomically)
 import Control.Monad.Stateless
 import Control.Monad.Trans.Control (MonadBaseControl (..))
 import Control.Monad.Trans.Managed (ManagedT (..), allocate_)
-import Control.Monad.Unique
 import Data.Aeson qualified as A
 import Data.ByteString.Char8 qualified as BC
 import Data.ByteString.Lazy.Char8 qualified as BLC
@@ -308,7 +307,6 @@ newtype PGMetadataStorageAppT m a = PGMetadataStorageAppT {runPGMetadataStorageA
       MonadMask,
       HasHttpManagerM,
       HasServerConfigCtx,
-      MonadUnique,
       MonadReader (Q.PGPool, Q.PGLogger)
     )
     via (ReaderT (Q.PGPool, Q.PGLogger) m)

server/src-lib/Hasura/Backends/BigQuery/Instances/Schema.hs

@@ -208,7 +208,7 @@ bqColumnParser columnType (G.Nullability isNullable) =
       BigQuery.DatetimeScalarType -> pure $ possiblyNullable scalarType $ BigQuery.DatetimeValue . BigQuery.Datetime <$> P.string
       BigQuery.GeographyScalarType -> pure $ possiblyNullable scalarType $ BigQuery.GeographyValue . BigQuery.Geography <$> P.string
       BigQuery.TimestampScalarType -> do
-        let schemaType = P.Nullable . P.TNamed $ P.mkDefinition stringScalar Nothing P.TIScalar
+        let schemaType = P.Nullable . P.TNamed $ P.Definition stringScalar Nothing P.TIScalar
         pure $
           possiblyNullable scalarType $
             Parser
@@ -233,11 +233,11 @@ bqColumnParser columnType (G.Nullability isNullable) =
       | otherwise = id
     mkEnumValue :: (EnumValue, EnumValueInfo) -> (P.Definition P.EnumValueInfo, ScalarValue 'BigQuery)
     mkEnumValue (EnumValue value, EnumValueInfo description) =
-      ( P.mkDefinition value (G.Description <$> description) P.EnumValueInfo,
+      ( P.Definition value (G.Description <$> description) P.EnumValueInfo,
         BigQuery.StringValue $ G.unName value
       )
     throughJSON scalarName =
-      let schemaType = P.NonNullable $ P.TNamed $ P.mkDefinition scalarName Nothing P.TIScalar
+      let schemaType = P.NonNullable $ P.TNamed $ P.Definition scalarName Nothing P.TIScalar
        in Parser
             { pType = schemaType,
               pParser =
@@ -278,7 +278,7 @@ bqOrderByOperators =
       )
     ]
   where
-    define name desc = P.mkDefinition name (Just desc) P.EnumValueInfo
+    define name desc = P.Definition name (Just desc) P.EnumValueInfo
 
 bqComparisonExps ::
   forall m n r.

server/src-lib/Hasura/Backends/MSSQL/Instances/Schema.hs

@@ -275,7 +275,7 @@ msColumnParser columnType (G.Nullability isNullable) =
         MSSQL.BitType -> pure $ ODBC.BoolValue <$> P.boolean
         _ -> do
           name <- MSSQL.mkMSSQLScalarTypeName scalarType
-          let schemaType = P.NonNullable $ P.TNamed $ P.mkDefinition name Nothing P.TIScalar
+          let schemaType = P.NonNullable $ P.TNamed $ P.Definition name Nothing P.TIScalar
           pure $
             Parser
               { pType = schemaType,
@@ -296,7 +296,7 @@ msColumnParser columnType (G.Nullability isNullable) =
       | otherwise = id
     mkEnumValue :: (EnumValue, EnumValueInfo) -> (P.Definition P.EnumValueInfo, ScalarValue 'MSSQL)
     mkEnumValue (EnumValue value, EnumValueInfo description) =
-      ( P.mkDefinition value (G.Description <$> description) P.EnumValueInfo,
+      ( P.Definition value (G.Description <$> description) P.EnumValueInfo,
         ODBC.TextValue $ G.unName value
       )
 
@@ -333,7 +333,7 @@ msOrderByOperators =
       )
     ]
   where
-    define name desc = P.mkDefinition name (Just desc) P.EnumValueInfo
+    define name desc = P.Definition name (Just desc) P.EnumValueInfo
 
 msComparisonExps ::
   forall m n r.

server/src-lib/Hasura/Backends/MySQL/Instances/Schema.hs

@@ -185,7 +185,7 @@ columnParser' columnType (G.Nullability isNullable) =
       MySQL.Timestamp -> pure $ possiblyNullable scalarType $ MySQL.TimestampValue <$> P.string
       _ -> do
         name <- MySQL.mkMySQLScalarTypeName scalarType
-        let schemaType = P.NonNullable $ P.TNamed $ P.mkDefinition name Nothing P.TIScalar
+        let schemaType = P.NonNullable $ P.TNamed $ P.Definition name Nothing P.TIScalar
         pure $
           Parser
             { pType = schemaType,
@@ -207,11 +207,11 @@ columnParser' columnType (G.Nullability isNullable) =
       | otherwise = id
     mkEnumValue :: (EnumValue, EnumValueInfo) -> (P.Definition P.EnumValueInfo, RQL.ScalarValue 'MySQL)
     mkEnumValue (RQL.EnumValue value, EnumValueInfo description) =
-      ( P.mkDefinition value (G.Description <$> description) P.EnumValueInfo,
+      ( P.Definition value (G.Description <$> description) P.EnumValueInfo,
         MySQL.VarcharValue $ G.unName value
       )
     throughJSON scalarName =
-      let schemaType = P.NonNullable $ P.TNamed $ P.mkDefinition scalarName Nothing P.TIScalar
+      let schemaType = P.NonNullable $ P.TNamed $ P.Definition scalarName Nothing P.TIScalar
        in Parser
             { pType = schemaType,
               pParser =
@@ -248,7 +248,7 @@ orderByOperators' =
       )
     ]
   where
-    define name desc = P.mkDefinition name (Just desc) P.EnumValueInfo
+    define name desc = P.Definition name (Just desc) P.EnumValueInfo
 
 -- | TODO: Make this as thorough as the one for MSSQL/PostgreSQL
 comparisonExps' ::

server/src-lib/Hasura/Backends/Postgres/Connection.hs

@@ -43,7 +43,6 @@ where
 import Control.Lens (makeLenses)
 import Control.Monad.Morph (hoist)
 import Control.Monad.Trans.Control (MonadBaseControl (..))
-import Control.Monad.Unique
 import Control.Monad.Validate
 import Data.Aeson
 import Data.Aeson.Casing (aesonDrop)
@@ -176,9 +175,6 @@ withTraceContext ctx tx = setTraceContextInTx ctx >> tx
 
 deriving instance Tracing.MonadTrace m => Tracing.MonadTrace (Q.TxET e m)
 
-instance (MonadIO m) => MonadUnique (Q.TxET e m) where
-  newUnique = liftIO newUnique
-
 checkDbConnection :: MonadIO m => Q.PGPool -> m Bool
 checkDbConnection pool = do
   e <- liftIO $ runExceptT $ Q.runTx' pool select1Query

server/src-lib/Hasura/Backends/Postgres/Instances/Schema.hs

@@ -214,7 +214,7 @@ columnParser columnType (G.Nullability isNullable) =
         --
         -- TODO: introduce new dedicated scalars for Postgres column types.
         name <- mkScalarTypeName scalarType
-        let schemaType = P.NonNullable $ P.TNamed $ P.mkDefinition name Nothing P.TIScalar
+        let schemaType = P.NonNullable $ P.TNamed $ P.Definition name Nothing P.TIScalar
         pure $
           Parser
             { pType = schemaType,
@@ -237,7 +237,7 @@ columnParser columnType (G.Nullability isNullable) =
       | otherwise = id
     mkEnumValue :: (EnumValue, EnumValueInfo) -> (P.Definition P.EnumValueInfo, PGScalarValue)
     mkEnumValue (EnumValue value, EnumValueInfo description) =
-      ( P.mkDefinition value (G.Description <$> description) P.EnumValueInfo,
+      ( P.Definition value (G.Description <$> description) P.EnumValueInfo,
         PGValText $ G.unName value
       )
 
@@ -283,7 +283,7 @@ orderByOperators =
       )
     ]
   where
-    define name desc = P.mkDefinition name (Just desc) P.EnumValueInfo
+    define name desc = P.Definition name (Just desc) P.EnumValueInfo
 
 comparisonExps ::
   forall pgKind m n r.

server/src-lib/Hasura/GraphQL/Parser/Class.hs

@@ -9,18 +9,15 @@ where
 import Data.Has
 import Data.HashMap.Strict qualified as Map
 import Data.Text.Extended
-import Data.Tuple.Extended
 import GHC.Stack (HasCallStack)
 import Hasura.Base.Error
 import Hasura.GraphQL.Parser.Class.Parse
 import Hasura.GraphQL.Parser.Internal.Types
-import Hasura.GraphQL.Parser.Schema (HasDefinition)
 import Hasura.Prelude
 import Hasura.RQL.Types.Backend
 import Hasura.RQL.Types.Common
 import Hasura.RQL.Types.Source
 import Hasura.RQL.Types.Table
--- import           Hasura.SQL.Backend
 import Hasura.Session (RoleName)
 import Language.Haskell.TH qualified as TH
 import Type.Reflection (Typeable)
@@ -103,8 +100,8 @@ class (Monad m, MonadParse n) => MonadSchema n m | m -> n where
   -- 'memoizeOn' :: 'MonadSchema' n m => 'TH.Name' -> a -> m (FieldParser n b) -> m (FieldParser n b)
   -- @
   memoizeOn ::
-    forall p d a b.
+    forall p a b.
-    (HasCallStack, HasDefinition (p n b) d, Ord a, Typeable p, Typeable a, Typeable b) =>
+    (HasCallStack, Ord a, Typeable p, Typeable a, Typeable b) =>
     -- | A unique name used to identify the function being memoized. There isn’t
     -- really any metaprogramming going on here, we just use a Template Haskell
     -- 'TH.Name' as a convenient source for a static, unique identifier.
@@ -152,46 +149,3 @@ memoize ::
   (a -> m (Parser k n b)) ->
   (a -> m (Parser k n b))
 memoize name f a = memoizeOn name a (f a)
-
-memoize2 ::
-  (HasCallStack, MonadSchema n m, Ord a, Ord b, Typeable a, Typeable b, Typeable c, Typeable k) =>
-  TH.Name ->
-  (a -> b -> m (Parser k n c)) ->
-  (a -> b -> m (Parser k n c))
-memoize2 name = curry . memoize name . uncurry
-
-memoize3 ::
-  ( HasCallStack,
-    MonadSchema n m,
-    Ord a,
-    Ord b,
-    Ord c,
-    Typeable a,
-    Typeable b,
-    Typeable c,
-    Typeable d,
-    Typeable k
-  ) =>
-  TH.Name ->
-  (a -> b -> c -> m (Parser k n d)) ->
-  (a -> b -> c -> m (Parser k n d))
-memoize3 name = curry3 . memoize name . uncurry3
-
-memoize4 ::
-  ( HasCallStack,
-    MonadSchema n m,
-    Ord a,
-    Ord b,
-    Ord c,
-    Ord d,
-    Typeable a,
-    Typeable b,
-    Typeable c,
-    Typeable d,
-    Typeable e,
-    Typeable k
-  ) =>
-  TH.Name ->
-  (a -> b -> c -> d -> m (Parser k n e)) ->
-  (a -> b -> c -> d -> m (Parser k n e))
-memoize4 name = curry4 . memoize name . uncurry4

server/src-lib/Hasura/GraphQL/Parser/Internal/Input.hs

@@ -188,7 +188,7 @@ field ::
 field name description parser = case pType parser of
   NonNullable typ ->
     InputFieldsParser
-      { ifDefinitions = [mkDefinition name description $ IFRequired typ],
+      { ifDefinitions = [Definition name description $ IFRequired typ],
         ifParser = \values -> withPath (++ [Key (unName name)]) do
           value <-
             onNothing (M.lookup name values) $
@@ -215,7 +215,7 @@ fieldOptional ::
 fieldOptional name description parser =
   InputFieldsParser
     { ifDefinitions =
-        [ mkDefinition name description $
+        [ Definition name description $
             IFOptional (nullableType $ pType parser) Nothing
         ],
       ifParser =
@@ -240,7 +240,7 @@ fieldWithDefault ::
   InputFieldsParser m a
 fieldWithDefault name description defaultValue parser =
   InputFieldsParser
-    { ifDefinitions = [mkDefinition name description $ IFOptional (pType parser) (Just defaultValue)],
+    { ifDefinitions = [Definition name description $ IFOptional (pType parser) (Just defaultValue)],
       ifParser =
         M.lookup name
           >>> withPath (++ [Key (unName name)]) . \case
@@ -270,7 +270,7 @@ enum name description values =
           other -> typeMismatch name "an enum value" other
     }
   where
-    schemaType = NonNullable $ TNamed $ mkDefinition name description $ TIEnum (fst <$> values)
+    schemaType = NonNullable $ TNamed $ Definition name description $ TIEnum (fst <$> values)
     valuesMap = M.fromList $ over (traverse . _1) dName $ toList values
     validate value =
       onNothing (M.lookup value valuesMap) $
@@ -314,7 +314,7 @@ object name description parser =
     schemaType =
       NonNullable $
         TNamed $
-          mkDefinition name description $
+          Definition name description $
             TIInputObject (InputObjectInfo (ifDefinitions parser))
     fieldNames = S.fromList (dName <$> ifDefinitions parser)
     parseFields fields = do

server/src-lib/Hasura/GraphQL/Parser/Internal/Parser.hs

@@ -50,9 +50,6 @@ data FieldParser m a = FieldParser
   }
   deriving (Functor)
 
-instance HasDefinition (FieldParser m a) FieldInfo where
-  definitionLens f parser = definitionLens f (fDefinition parser) <&> \fDefinition -> parser {fDefinition}
-
 infixl 1 `bindField`
 
 bindField :: Monad m => FieldParser m a -> (a -> m b) -> FieldParser m b
@@ -88,17 +85,17 @@ nullable parser =
 
 -- | Decorate a schema field as NON_NULL
 nonNullableField :: forall m a. FieldParser m a -> FieldParser m a
-nonNullableField (FieldParser (Definition n u d (FieldInfo as t)) p) =
+nonNullableField (FieldParser (Definition n d (FieldInfo as t)) p) =
-  FieldParser (Definition n u d (FieldInfo as (nonNullableType t))) p
+  FieldParser (Definition n d (FieldInfo as (nonNullableType t))) p
 
 -- | Decorate a schema field as NULL
 nullableField :: forall m a. FieldParser m a -> FieldParser m a
-nullableField (FieldParser (Definition n u d (FieldInfo as t)) p) =
+nullableField (FieldParser (Definition n d (FieldInfo as t)) p) =
-  FieldParser (Definition n u d (FieldInfo as (nullableType t))) p
+  FieldParser (Definition n d (FieldInfo as (nullableType t))) p
 
 multipleField :: forall m a. FieldParser m a -> FieldParser m a
-multipleField (FieldParser (Definition n u d (FieldInfo as t)) p) =
+multipleField (FieldParser (Definition n d (FieldInfo as t)) p) =
-  FieldParser (Definition n u d (FieldInfo as (Nullable (TList t)))) p
+  FieldParser (Definition n d (FieldInfo as (Nullable (TList t)))) p
 
 -- | Decorate a schema field with reference to given @'G.GType'
 wrapFieldParser :: forall m a. G.GType -> FieldParser m a -> FieldParser m a
@@ -164,7 +161,7 @@ selectionSetObject name description parsers implementsInterfaces =
     { pType =
         Nullable $
           TNamed $
-            mkDefinition name description $
+            Definition name description $
               TIObject $ ObjectInfo (map fDefinition parsers) interfaces,
       pParser = \input -> withPath (++ [Key "selectionSet"]) do
         -- Not all fields have a selection set, but if they have one, it
@@ -221,7 +218,7 @@ selectionSetInterface name description fields objectImplementations =
     { pType =
         Nullable $
           TNamed $
-            mkDefinition name description $
+            Definition name description $
               TIInterface $ InterfaceInfo (map fDefinition fields) objects,
       pParser = \input -> for objectImplementations (($ input) . pParser)
       -- Note: This is somewhat suboptimal, since it parses a query against every
@@ -249,7 +246,7 @@ selectionSetUnion name description objectImplementations =
     { pType =
         Nullable $
           TNamed $
-            mkDefinition name description $
+            Definition name description $
               TIUnion $ UnionInfo objects,
       pParser = \input -> for objectImplementations (($ input) . pParser)
     }
@@ -289,7 +286,7 @@ rawSelection ::
 rawSelection name description argumentsParser resultParser =
   FieldParser
     { fDefinition =
-        mkDefinition name description $
+        Definition name description $
           FieldInfo (ifDefinitions argumentsParser) (pType resultParser),
       fParser = \Field {_fAlias, _fArguments, _fSelectionSet} -> do
         unless (null _fSelectionSet) $
@@ -341,7 +338,7 @@ rawSubselection ::
 rawSubselection name description argumentsParser bodyParser =
   FieldParser
     { fDefinition =
-        mkDefinition name description $
+        Definition name description $
           FieldInfo (ifDefinitions argumentsParser) (pType bodyParser),
       fParser = \Field {_fAlias, _fArguments, _fSelectionSet} -> do
         -- check for extraneous arguments here, since the InputFieldsParser just

server/src-lib/Hasura/GraphQL/Parser/Internal/Scalars.hs

@@ -135,7 +135,7 @@ unsafeRawScalar ::
   Parser 'Both n (InputValue Variable)
 unsafeRawScalar name description =
   Parser
-    { pType = NonNullable $ TNamed $ mkDefinition name description TIScalar,
+    { pType = NonNullable $ TNamed $ Definition name description TIScalar,
       pParser = pure
     }
 
@@ -148,7 +148,7 @@ jsonScalar name description =
       pParser = valueToJSON $ toGraphQLType schemaType
     }
   where
-    schemaType = NonNullable $ TNamed $ mkDefinition name description TIScalar
+    schemaType = NonNullable $ TNamed $ Definition name description TIScalar
 
 --------------------------------------------------------------------------------
 -- Local helpers
@@ -165,7 +165,7 @@ mkScalar name description parser =
       pParser = peelVariable (toGraphQLType schemaType) >=> parser
     }
   where
-    schemaType = NonNullable $ TNamed $ mkDefinition name description TIScalar
+    schemaType = NonNullable $ TNamed $ Definition name description TIScalar
 
 convertWith ::
   MonadParse m =>

server/src-lib/Hasura/GraphQL/Parser/Internal/Types.hs

@@ -61,9 +61,6 @@ data Parser k m a = Parser
 instance HasName (Parser k m a) where
   getName = getName . pType
 
-instance HasDefinition (Parser k m a) (TypeInfo k) where
-  definitionLens f parser = definitionLens f (pType parser) <&> \pType -> parser {pType}
-
 type family ParserInput k where
 -- see Note [The 'Both kind] in Hasura.GraphQL.Parser.Schema
   ParserInput 'Both = InputValue Variable

server/src-lib/Hasura/GraphQL/Parser/Monad.hs

@@ -9,7 +9,6 @@ module Hasura.GraphQL.Parser.Monad
   )
 where
 
-import Control.Monad.Unique
 import Control.Monad.Validate
 import Data.Dependent.Map (DMap)
 import Data.Dependent.Map qualified as DM
@@ -21,7 +20,6 @@ import Data.Proxy (Proxy (..))
 import Data.Sequence.NonEmpty qualified as NE
 import Hasura.Base.Error
 import Hasura.GraphQL.Parser.Class
-import Hasura.GraphQL.Parser.Schema
 import Hasura.Prelude
 import Language.Haskell.TH qualified as TH
 import System.IO.Unsafe (unsafeInterleaveIO)
@@ -40,7 +38,7 @@ runSchemaT = flip evalStateT mempty . unSchemaT
 
 -- | see Note [SchemaT requires MonadIO]
 instance
-  (MonadIO m, MonadUnique m, MonadParse n) =>
+  (MonadIO m, MonadParse n) =>
   MonadSchema n (SchemaT n m)
   where
   memoizeOn name key buildParser = SchemaT do
@@ -84,8 +82,7 @@ instance
                       ]
         put $! DM.insert parserId parserById parsersById
 
-        unique <- newUnique
+        parser <- unSchemaT buildParser
-        parser <- addDefinitionUnique unique <$> unSchemaT buildParser
         liftIO $ writeIORef cell (Just parser)
         pure parser
 
@@ -96,7 +93,7 @@ instance
 deriving instance Monad m => MonadReader a (SchemaT n (ReaderT a m))
 
 instance
-  (MonadIO m, MonadUnique m, MonadParse n) =>
+  (MonadIO m, MonadParse n) =>
   MonadSchema n (ReaderT a (SchemaT n m))
   where
   memoizeOn name key = mapReaderT (memoizeOn name key)

server/src-lib/Hasura/GraphQL/Parser/Schema.hs

@@ -12,6 +12,7 @@ module Hasura.GraphQL.Parser.Schema
     Type (..),
     NonNullableType (..),
     TypeInfo (..),
+    getTypeInfo,
     SomeTypeInfo (..),
     eqType,
     eqNonNullableType,
@@ -32,9 +33,6 @@ module Hasura.GraphQL.Parser.Schema
 
     -- * Definitions
     Definition (..),
-    mkDefinition,
-    addDefinitionUnique,
-    HasDefinition (..),
 
     -- * Schemas
     Schema (..),
@@ -53,7 +51,6 @@ module Hasura.GraphQL.Parser.Schema
 where
 
 import Control.Lens.Extended
-import Control.Monad.Unique
 import Data.Aeson qualified as J
 import Data.Functor.Classes
 import Data.Has
@@ -324,10 +321,6 @@ eqType _ _ = False
 instance HasName (Type k) where
   getName = getName . discardNullability
 
-instance HasDefinition (Type k) (TypeInfo k) where
-  definitionLens f (NonNullable t) = NonNullable <$> definitionLens f t
-  definitionLens f (Nullable t) = Nullable <$> definitionLens f t
-
 discardNullability :: Type k -> NonNullableType k
 discardNullability (NonNullable t) = t
 discardNullability (Nullable t) = t
@@ -367,10 +360,6 @@ instance HasName (NonNullableType k) where
   getName (TNamed definition) = getName definition
   getName (TList t) = getName t
 
-instance HasDefinition (NonNullableType k) (TypeInfo k) where
-  definitionLens f (TNamed definition) = TNamed <$> f definition
-  definitionLens f (TList t) = TList <$> definitionLens f t
-
 {- Note [The interfaces story]
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 GraphQL interfaces are not conceptually complicated, but they pose some
@@ -541,19 +530,20 @@ eqTypeInfo (TIUnion (UnionInfo objects1)) (TIUnion (UnionInfo objects2)) =
   Set.fromList (fmap dName objects1) == Set.fromList (fmap dName objects2)
 eqTypeInfo _ _ = False
 
-getObjectInfo :: Type k -> Maybe (Definition ObjectInfo)
+getTypeInfo :: Type k -> Definition (TypeInfo k)
-getObjectInfo = traverse getTI . (^. definitionLens)
+getTypeInfo t = case discardNullability t of
-  where
+  TNamed d -> d
-    getTI :: TypeInfo k -> Maybe ObjectInfo
+  TList t' -> getTypeInfo t'
-    getTI (TIObject oi) = Just oi
-    getTI _ = Nothing
 
-getInterfaceInfo :: Type 'Output -> Maybe (Definition InterfaceInfo)
+getObjectInfo :: Type k -> Maybe (Definition ObjectInfo)
-getInterfaceInfo = traverse getTI . (^. definitionLens)
+getObjectInfo t = case getTypeInfo t of
-  where
+  d@Definition {dInfo = TIObject oi} -> Just d {dInfo = oi}
-    getTI :: TypeInfo 'Output -> Maybe InterfaceInfo
+  _ -> Nothing
-    getTI (TIInterface ii) = Just ii
+
-    getTI _ = Nothing
+getInterfaceInfo :: Type k -> Maybe (Definition InterfaceInfo)
+getInterfaceInfo t = case getTypeInfo t of
+  d@Definition {dInfo = TIInterface ii} -> Just d {dInfo = ii}
+  _ -> Nothing
 
 data SomeTypeInfo = forall k. SomeTypeInfo (TypeInfo k)
 
@@ -562,13 +552,6 @@ instance Eq SomeTypeInfo where
 
 data Definition a = Definition
   { dName :: Name,
-    -- | A unique identifier used to break cycles in mutually-recursive type
-    -- definitions. If two 'Definition's have the same 'Unique', they can be
-    -- assumed to be identical. Note that the inverse is /not/ true: two
-    -- definitions with different 'Unique's might still be otherwise identical.
-    --
-    -- Also see Note [Tying the knot] in Hasura.GraphQL.Parser.Class.
-    dUnique :: Maybe Unique,
     dDescription :: Maybe Description,
     -- | Lazy to allow mutually-recursive type definitions.
     dInfo :: ~a
@@ -579,39 +562,19 @@ instance Hashable a => Hashable (Definition a) where
   hashWithSalt salt Definition {..} =
     salt `hashWithSalt` dName `hashWithSalt` dInfo
 
-mkDefinition :: Name -> Maybe Description -> a -> Definition a
-mkDefinition name description info = Definition name Nothing description info
-
 instance Eq a => Eq (Definition a) where
   (==) = eq1
 
 instance Eq1 Definition where
   liftEq
     eq
-    (Definition name1 maybeUnique1 _ info1)
+    (Definition name1 _ info1)
-    (Definition name2 maybeUnique2 _ info2)
+    (Definition name2 _ info2) =
-      | Just unique1 <- maybeUnique1,
+      name1 == name2 && eq info1 info2
-        Just unique2 <- maybeUnique2,
-        unique1 == unique2 =
-        True
-      | otherwise =
-        name1 == name2 && eq info1 info2
 
 instance HasName (Definition a) where
   getName = dName
 
-class HasDefinition s a | s -> a where
-  definitionLens :: Lens' s (Definition a)
-
-instance HasDefinition (Definition a) a where
-  definitionLens = id
-
--- | Adds a 'Unique' to a 'Definition' that does not yet have one. If the
--- definition already has a 'Unique', the existing 'Unique' is kept.
-addDefinitionUnique :: HasDefinition s a => Unique -> s -> s
-addDefinitionUnique unique = over definitionLens \definition ->
-  definition {dUnique = dUnique definition <|> Just unique}
-
 -- | Enum values have no extra information except for the information common to
 -- all definitions, so this is just a placeholder for use as @'Definition'
 -- 'EnumValueInfo'@.

server/src-lib/Hasura/GraphQL/RemoteServer.hs

@@ -12,7 +12,6 @@ where
 import Control.Arrow.Extended (left)
 import Control.Exception (try)
 import Control.Lens (set, (^.))
-import Control.Monad.Unique
 import Data.Aeson ((.:), (.:?))
 import Data.Aeson qualified as J
 import Data.Aeson.Types qualified as J
@@ -142,7 +141,7 @@ validateSchemaCustomizationsDistinct remoteSchemaCustomizer (RemoteSchemaIntrosp
 -- and also is called by schema cache rebuilding code in "Hasura.RQL.DDL.Schema.Cache".
 fetchRemoteSchema ::
   forall m.
-  (MonadIO m, MonadUnique m, MonadError QErr m, Tracing.MonadTrace m) =>
+  (MonadIO m, MonadError QErr m, Tracing.MonadTrace m) =>
   Env.Environment ->
   HTTP.Manager ->
   RemoteSchemaName ->

server/src-lib/Hasura/GraphQL/Schema.hs

@@ -6,7 +6,6 @@ module Hasura.GraphQL.Schema
 where
 
 import Control.Lens.Extended
-import Control.Monad.Unique
 import Data.Aeson.Ordered qualified as JO
 import Data.Has
 import Data.HashMap.Strict qualified as Map
@@ -51,7 +50,6 @@ buildGQLContext ::
   forall m.
   ( MonadError QErr m,
     MonadIO m,
-    MonadUnique m,
     HasServerConfigCtx m
   ) =>
   GraphQLQueryType ->
@@ -102,7 +100,7 @@ buildGQLContext queryType sources allRemoteSchemas allActions nonObjectCustomTyp
   queryFieldNames :: [G.Name] <-
     case P.discardNullability $ P.parserType $ fst adminHasuraDBContext of
       -- It really ought to be this case; anything else is a programming error.
-      P.TNamed (P.Definition _ _ _ (P.TIObject (P.ObjectInfo rootFields _interfaces))) ->
+      P.TNamed (P.Definition _ _ (P.TIObject (P.ObjectInfo rootFields _interfaces))) ->
         pure $ fmap P.dName rootFields
       _ -> throw500 "We encountered an root query of unexpected GraphQL type.  It should be an object type."
   let mutationFieldNames :: [G.Name]
@@ -158,7 +156,7 @@ customizeFields SourceCustomization {..} =
 
 buildRoleContext ::
   forall m.
-  (MonadError QErr m, MonadIO m, MonadUnique m) =>
+  (MonadError QErr m, MonadIO m) =>
   (SQLGenCtx, GraphQLQueryType, FunctionPermissionsCtx) ->
   SourceCache ->
   RemoteSchemaCache ->
@@ -259,7 +257,7 @@ buildRoleContext
 
 buildRelayRoleContext ::
   forall m.
-  (MonadError QErr m, MonadIO m, MonadUnique m) =>
+  (MonadError QErr m, MonadIO m) =>
   (SQLGenCtx, GraphQLQueryType, FunctionPermissionsCtx) ->
   SourceCache ->
   [ActionInfo] ->
@@ -344,7 +342,7 @@ buildRelayRoleContext
 
 buildFullestDBSchema ::
   forall m.
-  (MonadError QErr m, MonadIO m, MonadUnique m) =>
+  (MonadError QErr m, MonadIO m) =>
   QueryContext ->
   SourceCache ->
   [ActionInfo] ->
@@ -403,8 +401,7 @@ buildFullestDBSchema queryContext sources allActionInfos nonObjectCustomTypes =
 unauthenticatedContext ::
   forall m.
   ( MonadError QErr m,
-    MonadIO m,
+    MonadIO m
-    MonadUnique m
   ) =>
   [P.FieldParser (P.ParseT Identity) (NamespacedField RemoteField)] ->
   [P.FieldParser (P.ParseT Identity) (NamespacedField RemoteField)] ->
@@ -426,7 +423,7 @@ unauthenticatedContext adminQueryRemotes adminMutationRemotes remoteSchemaPermsC
 
 buildRoleBasedRemoteSchemaParser ::
   forall m.
-  (MonadError QErr m, MonadUnique m, MonadIO m) =>
+  (MonadError QErr m, MonadIO m) =>
   RoleName ->
   RemoteSchemaCache ->
   m [(RemoteSchemaName, RemoteRelationshipQueryContext)]

server/src-lib/Hasura/GraphQL/Schema/Action.hs

@@ -360,7 +360,7 @@ customScalarParser = \case
         | _stdName == boolScalar -> J.toJSON <$> P.boolean
         | otherwise -> P.jsonScalar _stdName _stdDescription
   ASTReusedScalar name pgScalarType ->
-    let schemaType = P.NonNullable $ P.TNamed $ P.mkDefinition name Nothing P.TIScalar
+    let schemaType = P.NonNullable $ P.TNamed $ P.Definition name Nothing P.TIScalar
      in P.Parser
           { pType = schemaType,
             pParser =
@@ -381,7 +381,7 @@ customEnumParser (EnumTypeDefinition typeName description enumValues) =
         enumValues <&> \enumValue ->
           let valueName = G.unEnumValue $ _evdValue enumValue
            in (,J.toJSON valueName) $
-                P.mkDefinition
+                P.Definition
                   valueName
                   (_evdDescription enumValue)
                   P.EnumValueInfo

server/src-lib/Hasura/GraphQL/Schema/Introspect.hs

@@ -155,8 +155,8 @@ typeIntrospection fakeSchema = do
   name'printer <- P.subselection $$(G.litName "__type") Nothing nameArg typeField
   return $ case Map.lookup (fst name'printer) (sTypes fakeSchema) of
     Nothing -> J.Null
-    Just (P.Definition n u d (P.SomeTypeInfo i)) ->
+    Just (P.Definition n d (P.SomeTypeInfo i)) ->
-      snd name'printer (SomeType (P.Nullable (P.TNamed (P.Definition n u d i))))
+      snd name'printer (SomeType (P.Nullable (P.TNamed (P.Definition n d i))))
 
 -- | Generate a __schema introspection parser.
 schema ::
@@ -215,17 +215,17 @@ typeField =
                   J.String "NON_NULL"
                 P.Nullable (P.TList _) ->
                   J.String "LIST"
-                P.Nullable (P.TNamed (P.Definition _ _ _ P.TIScalar)) ->
+                P.Nullable (P.TNamed (P.Definition _ _ P.TIScalar)) ->
                   J.String "SCALAR"
-                P.Nullable (P.TNamed (P.Definition _ _ _ (P.TIEnum _))) ->
+                P.Nullable (P.TNamed (P.Definition _ _ (P.TIEnum _))) ->
                   J.String "ENUM"
-                P.Nullable (P.TNamed (P.Definition _ _ _ (P.TIInputObject _))) ->
+                P.Nullable (P.TNamed (P.Definition _ _ (P.TIInputObject _))) ->
                   J.String "INPUT_OBJECT"
-                P.Nullable (P.TNamed (P.Definition _ _ _ (P.TIObject _))) ->
+                P.Nullable (P.TNamed (P.Definition _ _ (P.TIObject _))) ->
                   J.String "OBJECT"
-                P.Nullable (P.TNamed (P.Definition _ _ _ (P.TIInterface _))) ->
+                P.Nullable (P.TNamed (P.Definition _ _ (P.TIInterface _))) ->
                   J.String "INTERFACE"
-                P.Nullable (P.TNamed (P.Definition _ _ _ (P.TIUnion _))) ->
+                P.Nullable (P.TNamed (P.Definition _ _ (P.TIUnion _))) ->
                   J.String "UNION"
       name :: FieldParser n (SomeType -> J.Value)
       name =
@@ -233,7 +233,7 @@ typeField =
           $> \case
             SomeType tp ->
               case tp of
-                P.Nullable (P.TNamed (P.Definition name' _ _ _)) ->
+                P.Nullable (P.TNamed (P.Definition name' _ _)) ->
                   nameAsJSON name'
                 _ -> J.Null
       description :: FieldParser n (SomeType -> J.Value)
@@ -242,7 +242,7 @@ typeField =
           $> \case
             SomeType tp ->
               case P.discardNullability tp of
-                P.TNamed (P.Definition _ _ (Just desc) _) ->
+                P.TNamed (P.Definition _ (Just desc) _) ->
                   J.String (G.unDescription desc)
                 _ -> J.Null
       fields :: FieldParser n (SomeType -> J.Value)
@@ -253,9 +253,9 @@ typeField =
           \case
             SomeType tp ->
               case tp of
-                P.Nullable (P.TNamed (P.Definition _ _ _ (P.TIObject (P.ObjectInfo fields' _interfaces')))) ->
+                P.Nullable (P.TNamed (P.Definition _ _ (P.TIObject (P.ObjectInfo fields' _interfaces')))) ->
                   J.Array $ V.fromList $ snd includeDeprecated'printer <$> sortOn P.dName fields'
-                P.Nullable (P.TNamed (P.Definition _ _ _ (P.TIInterface (P.InterfaceInfo fields' _objects')))) ->
+                P.Nullable (P.TNamed (P.Definition _ _ (P.TIInterface (P.InterfaceInfo fields' _objects')))) ->
                   J.Array $ V.fromList $ snd includeDeprecated'printer <$> sortOn P.dName fields'
                 _ -> J.Null
       interfaces :: FieldParser n (SomeType -> J.Value)
@@ -265,7 +265,7 @@ typeField =
           \case
             SomeType tp ->
               case tp of
-                P.Nullable (P.TNamed (P.Definition _ _ _ (P.TIObject (P.ObjectInfo _fields' interfaces')))) ->
+                P.Nullable (P.TNamed (P.Definition _ _ (P.TIObject (P.ObjectInfo _fields' interfaces')))) ->
                   J.Array $ V.fromList $ printer . SomeType . P.Nullable . P.TNamed . fmap P.TIInterface <$> sortOn P.dName interfaces'
                 _ -> J.Null
       possibleTypes :: FieldParser n (SomeType -> J.Value)
@@ -275,9 +275,9 @@ typeField =
           \case
             SomeType tp ->
               case tp of
-                P.Nullable (P.TNamed (P.Definition _ _ _ (P.TIInterface (P.InterfaceInfo _fields' objects')))) ->
+                P.Nullable (P.TNamed (P.Definition _ _ (P.TIInterface (P.InterfaceInfo _fields' objects')))) ->
                   J.Array $ V.fromList $ printer . SomeType . P.Nullable . P.TNamed . fmap P.TIObject <$> sortOn P.dName objects'
-                P.Nullable (P.TNamed (P.Definition _ _ _ (P.TIUnion (P.UnionInfo objects')))) ->
+                P.Nullable (P.TNamed (P.Definition _ _ (P.TIUnion (P.UnionInfo objects')))) ->
                   J.Array $ V.fromList $ printer . SomeType . P.Nullable . P.TNamed . fmap P.TIObject <$> sortOn P.dName objects'
                 _ -> J.Null
       enumValues :: FieldParser n (SomeType -> J.Value)
@@ -288,7 +288,7 @@ typeField =
           \case
             SomeType tp ->
               case tp of
-                P.Nullable (P.TNamed (P.Definition _ _ _ (P.TIEnum vals))) ->
+                P.Nullable (P.TNamed (P.Definition _ _ (P.TIEnum vals))) ->
                   J.Array $ V.fromList $ fmap (snd includeDeprecated'printer) $ sortOn P.dName $ toList vals
                 _ -> J.Null
       inputFields :: FieldParser n (SomeType -> J.Value)
@@ -298,7 +298,7 @@ typeField =
           \case
             SomeType tp ->
               case tp of
-                P.Nullable (P.TNamed (P.Definition _ _ _ (P.TIInputObject (P.InputObjectInfo fieldDefs)))) ->
+                P.Nullable (P.TNamed (P.Definition _ _ (P.TIInputObject (P.InputObjectInfo fieldDefs)))) ->
                   J.Array $ V.fromList $ map printer $ sortOn P.dName fieldDefs
                 _ -> J.Null
       ofType :: FieldParser n (SomeType -> J.Value)
@@ -440,7 +440,7 @@ typeKind =
         ]
     )
   where
-    mkDefinition name = (P.Definition name Nothing Nothing P.EnumValueInfo, ())
+    mkDefinition name = (P.Definition name Nothing P.EnumValueInfo, ())
 
 {-
 type __Field {
@@ -581,8 +581,8 @@ schemaSet fakeSchema =
           schemaTypeToSomeType ::
             P.Definition P.SomeTypeInfo ->
             SomeType
-          schemaTypeToSomeType (P.Definition n u d (P.SomeTypeInfo i)) =
+          schemaTypeToSomeType (P.Definition n d (P.SomeTypeInfo i)) =
-            SomeType $ P.Nullable $ P.TNamed (P.Definition n u d i)
+            SomeType $ P.Nullable $ P.TNamed (P.Definition n d i)
       queryType :: FieldParser n J.Value
       queryType = do
         printer <- P.subselection_ $$(G.litName "queryType") Nothing typeField

server/src-lib/Hasura/GraphQL/Schema/Mutation.hs

@@ -384,7 +384,7 @@ conflictConstraint constraints sourceName tableInfo =
     constraintEnumValues <- for constraints \constraint -> do
       name <- textToName $ toTxt $ _cName constraint
       pure
-        ( P.mkDefinition name (Just "unique or primary key constraint") P.EnumValueInfo,
+        ( P.Definition name (Just "unique or primary key constraint") P.EnumValueInfo,
           _cName constraint
         )
     enumName <- P.mkTypename $ tableGQLName <> $$(G.litName "_constraint")

server/src-lib/Hasura/GraphQL/Schema/Remote.hs

@@ -9,7 +9,6 @@ module Hasura.GraphQL.Schema.Remote
   )
 where
 
-import Control.Monad.Unique
 import Data.Has
 import Data.HashMap.Strict qualified as Map
 import Data.HashMap.Strict.InsOrd qualified as OMap
@@ -35,7 +34,7 @@ import Language.GraphQL.Draft.Syntax qualified as G
 
 buildRemoteParser ::
   forall m n.
-  (MonadIO m, MonadUnique m, MonadError QErr m, MonadParse n) =>
+  (MonadIO m, MonadError QErr m, MonadParse n) =>
   IntrospectionResult ->
   RemoteSchemaInfo ->
   m (ParsedIntrospectionG n)
@@ -350,7 +349,7 @@ remoteFieldScalarParser customizeTypename (G.ScalarTypeDefinition description na
     }
   where
     customizedTypename = runMkTypename customizeTypename name
-    schemaType = NonNullable $ TNamed $ mkDefinition customizedTypename description TIScalar
+    schemaType = NonNullable $ TNamed $ Definition customizedTypename description TIScalar
     gType = toGraphQLType schemaType
 
     mkRemoteGType = \case
@@ -365,7 +364,7 @@ remoteFieldEnumParser ::
 remoteFieldEnumParser customizeTypename (G.EnumTypeDefinition desc name _directives valueDefns) =
   let enumValDefns =
         valueDefns <&> \(G.EnumValueDefinition enumDesc enumName _) ->
-          ( mkDefinition (G.unEnumValue enumName) enumDesc P.EnumValueInfo,
+          ( Definition (G.unEnumValue enumName) enumDesc P.EnumValueInfo,
             G.VEnum enumName
           )
    in fmap (Altered False,) $ P.enum (runMkTypename customizeTypename name) desc $ NE.fromList enumValDefns
@@ -841,12 +840,12 @@ remoteFieldFromDefinition ::
   m (FieldParser n (G.Field G.NoFragments RemoteSchemaVariable))
 remoteFieldFromDefinition schemaDoc parentTypeName (G.FieldDefinition description name argsDefinition gType _) = do
   let addNullableList :: FieldParser n a -> FieldParser n a
-      addNullableList (P.FieldParser (Definition name' un desc (FieldInfo args typ)) parser) =
+      addNullableList (P.FieldParser (Definition name' desc (FieldInfo args typ)) parser) =
-        P.FieldParser (Definition name' un desc (FieldInfo args (Nullable (TList typ)))) parser
+        P.FieldParser (Definition name' desc (FieldInfo args (Nullable (TList typ)))) parser
 
       addNonNullableList :: FieldParser n a -> FieldParser n a
-      addNonNullableList (P.FieldParser (Definition name' un desc (FieldInfo args typ)) parser) =
+      addNonNullableList (P.FieldParser (Definition name' desc (FieldInfo args typ)) parser) =
-        P.FieldParser (Definition name' un desc (FieldInfo args (NonNullable (TList typ)))) parser
+        P.FieldParser (Definition name' desc (FieldInfo args (NonNullable (TList typ)))) parser
 
       -- TODO add directives, deprecation
       convertType :: G.GType -> m (FieldParser n (G.Field G.NoFragments RemoteSchemaVariable))

server/src-lib/Hasura/GraphQL/Schema/Table.hs

@@ -80,7 +80,7 @@ tableSelectColumnsEnum sourceName tableInfo selectPermissions = do
         ]
   where
     define name =
-      P.mkDefinition name (Just $ G.Description "column name") P.EnumValueInfo
+      P.Definition name (Just $ G.Description "column name") P.EnumValueInfo
 
 -- | Table update columns enum
 --
@@ -111,8 +111,8 @@ tableUpdateColumnsEnum tableInfo updatePermissions = do
     Just values -> P.enum enumName enumDesc values
     Nothing -> P.enum enumName altDesc $ pure (placeholder, Nothing)
   where
-    define name = P.mkDefinition name (Just $ G.Description "column name") P.EnumValueInfo
+    define name = P.Definition name (Just $ G.Description "column name") P.EnumValueInfo
-    placeholder = P.mkDefinition @P.EnumValueInfo $$(G.litName "_PLACEHOLDER") (Just $ G.Description "placeholder (do not use)") P.EnumValueInfo
+    placeholder = P.Definition @P.EnumValueInfo $$(G.litName "_PLACEHOLDER") (Just $ G.Description "placeholder (do not use)") P.EnumValueInfo
 
 tablePermissions ::
   forall m n r b.

server/src-lib/Hasura/RQL/DDL/RemoteSchema.hs

@@ -14,7 +14,6 @@ module Hasura.RQL.DDL.RemoteSchema
 where
 
 import Control.Lens ((^.))
-import Control.Monad.Unique
 import Data.Environment qualified as Env
 import Data.HashMap.Strict qualified as Map
 import Data.HashMap.Strict.InsOrd qualified as OMap
@@ -34,7 +33,6 @@ runAddRemoteSchema ::
   ( QErrM m,
     CacheRWM m,
     MonadIO m,
-    MonadUnique m,
     HasHttpManagerM m,
     MetadataM m,
     Tracing.MonadTrace m
@@ -125,7 +123,7 @@ addRemoteSchemaP1 name = do
         <> name <<> " already exists"
 
 addRemoteSchemaP2Setup ::
-  (QErrM m, MonadIO m, MonadUnique m, HasHttpManagerM m, Tracing.MonadTrace m) =>
+  (QErrM m, MonadIO m, HasHttpManagerM m, Tracing.MonadTrace m) =>
   Env.Environment ->
   AddRemoteSchemaQuery ->
   m RemoteSchemaCtx
@@ -213,7 +211,6 @@ runUpdateRemoteSchema ::
   ( QErrM m,
     CacheRWM m,
     MonadIO m,
-    MonadUnique m,
     HasHttpManagerM m,
     MetadataM m,
     Tracing.MonadTrace m

server/src-lib/Hasura/RQL/DDL/Schema/Cache.hs

@@ -24,7 +24,6 @@ import Control.Arrow.Extended
 import Control.Concurrent.Async.Lifted.Safe qualified as LA
 import Control.Lens hiding ((.=))
 import Control.Monad.Trans.Control (MonadBaseControl)
-import Control.Monad.Unique
 import Control.Retry qualified as Retry
 import Data.Aeson
 import Data.Align (align)
@@ -147,7 +146,6 @@ newtype CacheRWT m a
       Applicative,
       Monad,
       MonadIO,
-      MonadUnique,
       MonadReader r,
       MonadError e,
       MonadTx,
@@ -227,7 +225,6 @@ buildSchemaCacheRule ::
     Inc.ArrowDistribute arr,
     Inc.ArrowCache m arr,
     MonadIO m,
-    MonadUnique m,
     MonadBaseControl IO m,
     MonadError QErr m,
     MonadReader BuildReason m,
@@ -560,7 +557,6 @@ buildSchemaCacheRule logger env = proc (metadata, invalidationKeys) -> do
         Inc.ArrowCache m arr,
         ArrowWriter (Seq CollectedInfo) arr,
         MonadIO m,
-        MonadUnique m,
         MonadError QErr m,
         MonadReader BuildReason m,
         MonadBaseControl IO m,
@@ -1134,7 +1130,6 @@ buildSchemaCacheRule logger env = proc (metadata, invalidationKeys) -> do
         ArrowWriter (Seq CollectedInfo) arr,
         Inc.ArrowCache m arr,
         MonadIO m,
-        MonadUnique m,
         HasHttpManagerM m
       ) =>
       ( Inc.Dependency (HashMap RemoteSchemaName Inc.InvalidationKey),

server/src-lib/Hasura/RQL/Types.hs

@@ -30,7 +30,6 @@ module Hasura.RQL.Types
 where
 
 import Control.Lens (Traversal', at, preview, (^.))
-import Control.Monad.Unique
 import Data.HashMap.Strict qualified as M
 import Data.Text.Extended
 import Database.PG.Query qualified as Q
@@ -242,7 +241,6 @@ newtype HasSystemDefinedT m a = HasSystemDefinedT {unHasSystemDefinedT :: Reader
       Monad,
       MonadTrans,
       MonadIO,
-      MonadUnique,
       MonadError e,
       MonadTx,
       HasHttpManagerM,

server/src-lib/Hasura/RQL/Types/Run.hs

@@ -8,7 +8,6 @@ module Hasura.RQL.Types.Run
 where
 
 import Control.Monad.Trans.Control (MonadBaseControl)
-import Control.Monad.Unique
 import Hasura.Base.Error
 import Hasura.Metadata.Class
 import Hasura.Prelude
@@ -35,9 +34,6 @@ newtype RunT m a = RunT {unRunT :: ReaderT RunCtx (ExceptT QErr m) a}
       Tracing.MonadTrace
     )
 
-instance (MonadIO m) => MonadUnique (RunT m) where
-  newUnique = liftIO newUnique
-
 instance (MonadMetadataStorage m) => MonadMetadataStorageQueryAPI (RunT m)
 
 deriving instance (MonadIO m, MonadBase IO m) => MonadBase IO (RunT m)

server/src-lib/Hasura/RQL/Types/SchemaCache/Build.hs

@@ -28,7 +28,6 @@ import Control.Arrow.Extended
 import Control.Lens
 import Control.Monad.Morph
 import Control.Monad.Trans.Control (MonadBaseControl)
-import Control.Monad.Unique
 import Data.Aeson (Value, toJSON)
 import Data.Aeson.TH
 import Data.HashMap.Strict.Extended qualified as M
@@ -210,7 +209,6 @@ newtype MetadataT m a = MetadataT {unMetadataT :: StateT Metadata m a}
       Monad,
       MonadTrans,
       MonadIO,
-      MonadUnique,
       MonadReader r,
       MonadError e,
       MonadTx,

server/src-lib/Hasura/Server/API/Metadata.hs

@@ -9,7 +9,6 @@ module Hasura.Server.API.Metadata
 where
 
 import Control.Monad.Trans.Control (MonadBaseControl)
-import Control.Monad.Unique
 import Data.Aeson
 import Data.Aeson.Casing
 import Data.Aeson.Types qualified as A
@@ -355,7 +354,6 @@ runMetadataQueryM ::
     CacheRWM m,
     Tracing.MonadTrace m,
     UserInfoM m,
-    MonadUnique m,
     HTTP.HasHttpManagerM m,
     MetadataM m,
     MonadMetadataStorageQueryAPI m,
@@ -379,7 +377,6 @@ runMetadataQueryV1M ::
     CacheRWM m,
     Tracing.MonadTrace m,
     UserInfoM m,
-    MonadUnique m,
     HTTP.HasHttpManagerM m,
     MetadataM m,
     MonadMetadataStorageQueryAPI m,

server/src-lib/Hasura/Server/API/Query.hs

@@ -8,7 +8,6 @@ module Hasura.Server.API.Query
 where
 
 import Control.Monad.Trans.Control (MonadBaseControl)
-import Control.Monad.Unique
 import Data.Aeson
 import Data.Aeson.Casing
 import Data.Aeson.TH
@@ -288,7 +287,6 @@ runQueryM ::
     UserInfoM m,
     MonadBaseControl IO m,
     MonadIO m,
-    MonadUnique m,
     HasHttpManagerM m,
     HasServerConfigCtx m,
     Tracing.MonadTrace m,

server/src-lib/Hasura/Tracing.hs

@@ -24,7 +24,6 @@ import Control.Lens (over, view, (^?))
 import Control.Monad.Catch (MonadCatch, MonadMask, MonadThrow)
 import Control.Monad.Morph
 import Control.Monad.Trans.Control
-import Control.Monad.Unique
 import Data.Aeson qualified as J
 import Data.Aeson.Lens qualified as JL
 import Data.Binary qualified as Bin
@@ -84,7 +83,7 @@ data TraceContext = TraceContext
 -- | The 'TraceT' monad transformer adds the ability to keep track of
 -- the current trace context.
 newtype TraceT m a = TraceT {unTraceT :: ReaderT (TraceContext, Reporter) (WriterT TracingMetadata m) a}
-  deriving (Functor, Applicative, Monad, MonadIO, MonadUnique, MonadMask, MonadCatch, MonadThrow)
+  deriving (Functor, Applicative, Monad, MonadIO, MonadMask, MonadCatch, MonadThrow)
 
 instance MonadTrans TraceT where
   lift = TraceT . lift . lift

server/src-test/Hasura/GraphQL/Parser/TestUtils.hs

@@ -44,12 +44,12 @@ fakeInputFieldValue = \case
     fromNNT :: forall k. ('Input <: k) => NonNullableType k -> G.Value Variable
     fromNNT = \case
       TList t -> G.VList [fromT t, fromT t]
-      TNamed (Definition name _ _ info) -> case info of
+      TNamed (Definition name _ info) -> case info of
         TIScalar -> fakeScalar name
         TIEnum ei -> G.VEnum $ G.EnumValue $ dName $ NE.head ei
         TIInputObject (InputObjectInfo oi) -> G.VObject $
           M.fromList $ do
-            Definition fieldName _ _ fieldInfo <- oi
+            Definition fieldName _ fieldInfo <- oi
             pure (fieldName, fakeInputFieldValue fieldInfo)
         _ -> error "impossible"
 
@@ -57,5 +57,5 @@ fakeDirective :: DirectiveInfo -> G.Directive Variable
 fakeDirective DirectiveInfo {..} =
   G.Directive diName $
     M.fromList $
-      diArguments <&> \(Definition argName _ _ argInfo) ->
+      diArguments <&> \(Definition argName _ argInfo) ->
         (argName, fakeInputFieldValue argInfo)

server/src-test/Hasura/Server/MigrateSpec.hs

@@ -5,7 +5,6 @@ module Hasura.Server.MigrateSpec (CacheRefT (..), spec) where
 import Control.Concurrent.MVar.Lifted
 import Control.Monad.Morph
 import Control.Monad.Trans.Control (MonadBaseControl)
-import Control.Monad.Unique
 import Control.Natural ((:~>) (..))
 import Data.Aeson (encode)
 import Data.ByteString.Lazy.UTF8 qualified as LBS
@@ -43,7 +42,6 @@ newtype CacheRefT m a = CacheRefT {runCacheRefT :: MVar RebuildableSchemaCache -
       MonadBase b,
       MonadBaseControl b,
       MonadTx,
-      MonadUnique,
       UserInfoM,
       HTTP.HasHttpManagerM,
       HasServerConfigCtx,