fix: emit pass for empty generated classes

internal/endtoend/testdata/query_parameter_limit_zero/python/query.py

@@ -3,13 +3,24 @@
 #   sqlc v1.28.0
 # source: query.sql
 import dataclasses
+from typing import Optional
 
 import sqlalchemy
 import sqlalchemy.ext.asyncio
 
 from querytest import models
 
 
+COUNT_BARS = """-- name: count_bars \\:one
+SELECT count(*) FROM bar
+"""
+
+
+@dataclasses.dataclass()
+class CountBarsParams:
+    pass
+
+
 DELETE_BAR_BY_ID = """-- name: delete_bar_by_id \\:execrows
 DELETE FROM bar WHERE id = :p1
 """
@@ -35,6 +46,12 @@ class Querier:
     def __init__(self, conn: sqlalchemy.engine.Connection):
         self._conn = conn
 
+    def count_bars(self, arg: CountBarsParams) -> Optional[int]:
+        row = self._conn.execute(sqlalchemy.text(COUNT_BARS), {}).first()
+        if row is None:
+            return None
+        return row[0]
+
     def delete_bar_by_id(self, arg: DeleteBarByIDParams) -> int:
         result = self._conn.execute(sqlalchemy.text(DELETE_BAR_BY_ID), {"p1": arg.id})
         return result.rowcount
@@ -48,6 +65,12 @@ class AsyncQuerier:
     def __init__(self, conn: sqlalchemy.ext.asyncio.AsyncConnection):
         self._conn = conn
 
+    async def count_bars(self, arg: CountBarsParams) -> Optional[int]:
+        row = (await self._conn.execute(sqlalchemy.text(COUNT_BARS), {})).first()
+        if row is None:
+            return None
+        return row[0]
+
     async def delete_bar_by_id(self, arg: DeleteBarByIDParams) -> int:
         result = await self._conn.execute(sqlalchemy.text(DELETE_BAR_BY_ID), {"p1": arg.id})
         return result.rowcount

internal/endtoend/testdata/query_parameter_limit_zero/query.sql

@@ -3,3 +3,6 @@ DELETE FROM bar WHERE id = $1;
 
 -- name: DeleteBarByIDAndName :execrows
 DELETE FROM bar WHERE id = $1 AND name = $2;
+
+-- name: CountBars :one
+SELECT count(*) FROM bar;

internal/printer/printer.go

@@ -238,6 +238,11 @@ func (w *writer) printClassDef(cd *ast.ClassDef, indent int32) {
 		w.print(")")
 	}
 	w.print(":\n")
+	if len(cd.Body) == 0 {
+		w.printIndent(indent + 1)
+		w.print("pass\n")
+		return
+	}
 	for i, node := range cd.Body {
 		if i != 0 {
 			if _, ok := node.Node.(*ast.Node_FunctionDef); ok {

internal/printer/printer_test.go

@@ -68,7 +68,10 @@ func TestPrinter(t *testing.T) {
 					},
 				},
 			},
-			Expected: `class Foo(str, enum.Enum):`,
+			Expected: `
+class Foo(str, enum.Enum):
+    pass
+`,
 		},
 		"dataclass": {
 			Node: &ast.Node{
@@ -125,6 +128,29 @@ func TestPrinter(t *testing.T) {
 class Foo:
     bar: int
     bat: Optional[int]
+`,
+		},
+		"empty-dataclass": {
+			Node: &ast.Node{
+				Node: &ast.Node_ClassDef{
+					ClassDef: &ast.ClassDef{
+						Name: "Foo",
+						DecoratorList: []*ast.Node{
+							{
+								Node: &ast.Node_Name{
+									Name: &ast.Name{
+										Id: "dataclass",
+									},
+								},
+							},
+						},
+					},
+				},
+			},
+			Expected: `
+@dataclass
+class Foo:
+    pass
 `,
 		},
 		"call": {