Fixed KeyError when rendering an empty index

Fixes #192.

Author: agronholm

CHANGES.rst

@@ -4,6 +4,7 @@ Version history
 **UNRELEASED**
 
 - Migrated all packaging/testing configuration to ``pyproject.toml``
+. Fixed ``KeyError`` when rendering an index without any columns
 
 **3.0.0b3**
 

src/sqlacodegen/utils.py

@@ -127,11 +127,10 @@ def uses_default_name(constraint: Constraint | Index) -> bool:
 
     try:
         convention: str = table.metadata.naming_convention[key]
+        return constraint.name == (convention % values)
     except KeyError:
         return False
 
-    return constraint.name == (convention % values)
-
 
 def render_callable(
     name: str,

tests/test_generators.py

@@ -300,6 +300,7 @@ def test_indexes(self, generator: CodeGenerator) -> None:
             Column("id", INTEGER),
             Column("number", INTEGER),
             Column("text", VARCHAR),
+            Index("ix_empty"),
         )
         simple_items.indexes.add(Index("ix_number", simple_items.c.number))
         simple_items.indexes.add(
@@ -325,6 +326,7 @@ def test_indexes(self, generator: CodeGenerator) -> None:
                 Column('id', Integer),
                 Column('number', Integer, index=True),
                 Column('text', String, unique=True),
+                Index('ix_empty'),
                 Index('ix_text_number', 'text', 'number', unique=True)
             )
             """,