chore(internal): support rendering enum types from the DMMF

This will be helpful for transaction isolation levels support

#878

Author: RobertCraigie

src/prisma/generator/models.py

@@ -353,6 +353,7 @@ def to_params(self) -> Dict[str, Any]:
         """Get the parameters that should be sent to Jinja templates"""
         params = vars(self)
         params['type_schema'] = Schema.from_data(self)
+        params['client_types'] = ClientTypes.from_data(self)
 
         # add utility functions
         for func in [
@@ -628,11 +629,22 @@ def engine_type_validator(cls, value: EngineType) -> EngineType:
             assert_never(value)
 
 
+class EnumType(BaseModel):
+    name: str
+    values: List[object]
+
+
+class EnumTypes(BaseModel):
+    prisma: List[EnumType]
+
+
+class PrismaSchema(BaseModel):
+    enum_types: EnumTypes = FieldInfo(alias='enumTypes')
+
+
 class DMMF(BaseModel):
     datamodel: 'Datamodel'
-
-    # TODO
-    prisma_schema: Any = FieldInfo(alias='schema')
+    prisma_schema: PrismaSchema = FieldInfo(alias='schema')
 
 
 class Datamodel(BaseModel):
@@ -1182,4 +1194,4 @@ class DefaultData(GenericData[_EmptyModel]):
     TemplateError,
     PartialTypeGeneratorError,
 )
-from .schema import Schema
+from .schema import Schema, ClientTypes

src/prisma/generator/schema.py

@@ -1,9 +1,10 @@
 from enum import Enum
-from typing import Any, Dict, List, Type, Tuple, Union
+from typing import Any, Dict, List, Type, Tuple, Union, Optional
 from typing_extensions import ClassVar
 
 from pydantic import BaseModel
 
+from .utils import to_constant_case
 from .models import Model as ModelInfo, AnyData, PrimaryKey
 from .._compat import (
     PYDANTIC_V2,
@@ -18,6 +19,7 @@ class Kind(str, Enum):
     alias = 'alias'
     union = 'union'
     typeddict = 'typeddict'
+    enum = 'enum'
 
 
 class PrismaType(BaseModel):
@@ -45,6 +47,11 @@ class PrismaUnion(PrismaType):
     subtypes: List[PrismaType]
 
 
+class PrismaEnum(PrismaType):
+    kind: Kind = Kind.enum
+    members: List[Tuple[str, str]]
+
+
 class PrismaAlias(PrismaType):
     kind: Kind = Kind.alias
     to: str
@@ -143,6 +150,28 @@ def order_by(self) -> PrismaType:
         return PrismaType.from_subtypes(subtypes, name=f'{model}OrderByInput')
 
 
+class ClientTypes(BaseModel):
+    transaction_isolation_level: Optional[PrismaEnum]
+
+    @classmethod
+    def from_data(cls, data: AnyData) -> 'ClientTypes':
+        enum_types = data.dmmf.prisma_schema.enum_types.prisma
+
+        tx_isolation = next((t for t in enum_types if t.name == 'TransactionIsolationLevel'), None)
+        if tx_isolation is not None:
+            tx_isolation = PrismaEnum(
+                name='TransactionIsolationLevel',
+                members=[
+                    (to_constant_case(str(value)), str(value))
+                    for value in tx_isolation.values
+                ],
+            )
+
+        return cls(
+            transaction_isolation_level=tx_isolation,
+        )
+
+
 model_rebuild(Schema)
 model_rebuild(PrismaType)
 model_rebuild(PrismaDict)

src/prisma/generator/templates/types.py.jinja

@@ -65,6 +65,11 @@ from .utils import _NoneType
     },
     total={{ type.total }}
 )
+{% elif type.kind == 'enum' %}
+class {{ type.name }}(StrEnum):
+    {% for name, value in type.members %}
+    {{ name }} = "{{ value }}"
+    {% endfor %}
 {% else %}
 {{ raise_err('Unhandled type kind: %s' % type.kind) }}
 {% endif %}