DOMAIN as JSON bindings fixes (#407)

* Test formatting fix

* Added test coverage

* test name fix

* Support non-default jsons

* Update src/sqlacodegen/generators.py

Co-authored-by: Alex Grönholm <alex.gronholm@nextday.fi>

* PR Fixes

* PR Fixes

---------

Co-authored-by: Alex Grönholm <alex.gronholm@nextday.fi>

Author: sheinbergon

.gitignore

@@ -13,3 +13,4 @@
 dist
 build
 venv*
+docker-compose.yaml

CHANGES.rst

@@ -10,6 +10,7 @@ Version history
 - Fixed incorrect package name used in ``importlib.metadata.version`` for
   ``sqlalchemy-citext``, resolving ``PackageNotFoundError`` (PR by @oaimtiaz)
 - Prevent double pluralization (PR by @dkratzert)
+- Fixes DOMAIN extending JSON/JSONB data types (PR by @sheinbergon)
 
 **3.0.0**
 

src/sqlacodegen/generators.py

@@ -38,7 +38,7 @@
     TypeDecorator,
     UniqueConstraint,
 )
-from sqlalchemy.dialects.postgresql import DOMAIN, JSONB
+from sqlalchemy.dialects.postgresql import DOMAIN, JSON, JSONB
 from sqlalchemy.engine import Connection, Engine
 from sqlalchemy.exc import CompileError
 from sqlalchemy.sql.elements import TextClause
@@ -222,7 +222,7 @@ def collect_imports_for_column(self, column: Column[Any]) -> None:
 
         if isinstance(column.type, ARRAY):
             self.add_import(column.type.item_type.__class__)
-        elif isinstance(column.type, JSONB):
+        elif isinstance(column.type, (JSONB, JSON)):
             if (
                 not isinstance(column.type.astext_type, Text)
                 or column.type.astext_type.length is not None
@@ -499,7 +499,7 @@ def render_column_callable(self, is_table: bool, *args: Any, **kwargs: Any) -> s
         else:
             return render_callable("mapped_column", *args, kwargs=kwargs)
 
-    def render_column_type(self, coltype: object) -> str:
+    def render_column_type(self, coltype: TypeEngine[Any]) -> str:
         args = []
         kwargs: dict[str, Any] = {}
         sig = inspect.signature(coltype.__class__.__init__)
@@ -515,6 +515,17 @@ def render_column_type(self, coltype: object) -> str:
                 continue
 
             value = getattr(coltype, param.name, missing)
+
+            if isinstance(value, (JSONB, JSON)):
+                # Remove astext_type if it's the default
+                if (
+                    isinstance(value.astext_type, Text)
+                    and value.astext_type.length is None
+                ):
+                    value.astext_type = None  # type: ignore[assignment]
+                else:
+                    self.add_import(Text)
+
             default = defaults.get(param.name, missing)
             if isinstance(value, TextClause):
                 self.add_literal_import("sqlalchemy", "text")
@@ -547,7 +558,7 @@ def render_column_type(self, coltype: object) -> str:
                 if (value := getattr(coltype, colname)) is not None:
                     kwargs[colname] = repr(value)
 
-        if isinstance(coltype, JSONB):
+        if isinstance(coltype, (JSONB, JSON)):
             # Remove astext_type if it's the default
             if (
                 isinstance(coltype.astext_type, Text)
@@ -1224,7 +1235,11 @@ def get_type_qualifiers() -> tuple[str, TypeEngine[Any], str]:
             return "".join(pre), column_type, "]" * post_size
 
         def render_python_type(column_type: TypeEngine[Any]) -> str:
-            python_type = column_type.python_type
+            if isinstance(column_type, DOMAIN):
+                python_type = column_type.data_type.python_type
+            else:
+                python_type = column_type.python_type
+
             python_type_name = python_type.__name__
             python_type_module = python_type.__module__
             if python_type_module == "builtins":

tests/test_generator_declarative.py

@@ -2,7 +2,9 @@
 
 import pytest
 from _pytest.fixtures import FixtureRequest
-from sqlalchemy import PrimaryKeyConstraint
+from sqlalchemy import BIGINT, PrimaryKeyConstraint
+from sqlalchemy.dialects import postgresql
+from sqlalchemy.dialects.postgresql import JSON, JSONB
 from sqlalchemy.engine import Engine
 from sqlalchemy.schema import (
     CheckConstraint,
@@ -1592,3 +1594,87 @@ class WithItems(Base):
     str_matrix: Mapped[Optional[list[list[str]]]] = mapped_column(ARRAY(VARCHAR(), dimensions=2))
 """,
     )
+
+
+@pytest.mark.parametrize("engine", ["postgresql"], indirect=["engine"])
+def test_domain_json(generator: CodeGenerator) -> None:
+    Table(
+        "test_domain_json",
+        generator.metadata,
+        Column("id", BIGINT, primary_key=True),
+        Column(
+            "foo",
+            postgresql.DOMAIN(
+                "domain_json",
+                JSON,
+                not_null=False,
+            ),
+            nullable=True,
+        ),
+    )
+
+    validate_code(
+        generator.generate(),
+        """\
+from typing import Optional
+
+from sqlalchemy import BigInteger
+from sqlalchemy.dialects.postgresql import DOMAIN, JSON
+from sqlalchemy.orm import DeclarativeBase, Mapped, mapped_column
+
+class Base(DeclarativeBase):
+    pass
+
+
+class TestDomainJson(Base):
+    __tablename__ = 'test_domain_json'
+
+    id: Mapped[int] = mapped_column(BigInteger, primary_key=True)
+    foo: Mapped[Optional[dict]] = mapped_column(DOMAIN('domain_json', JSON(), not_null=False))
+""",
+    )
+
+
+@pytest.mark.parametrize(
+    "domain_type",
+    [JSONB, JSON],
+)
+def test_domain_non_default_json(
+    generator: CodeGenerator,
+    domain_type: type[JSON] | type[JSONB],
+) -> None:
+    Table(
+        "test_domain_json",
+        generator.metadata,
+        Column("id", BIGINT, primary_key=True),
+        Column(
+            "foo",
+            postgresql.DOMAIN(
+                "domain_json",
+                domain_type(astext_type=Text(128)),
+                not_null=False,
+            ),
+            nullable=True,
+        ),
+    )
+
+    validate_code(
+        generator.generate(),
+        f"""\
+from typing import Optional
+
+from sqlalchemy import BigInteger, Text
+from sqlalchemy.dialects.postgresql import DOMAIN, {domain_type.__name__}
+from sqlalchemy.orm import DeclarativeBase, Mapped, mapped_column
+
+class Base(DeclarativeBase):
+    pass
+
+
+class TestDomainJson(Base):
+    __tablename__ = 'test_domain_json'
+
+    id: Mapped[int] = mapped_column(BigInteger, primary_key=True)
+    foo: Mapped[Optional[dict]] = mapped_column(DOMAIN('domain_json', {domain_type.__name__}(astext_type=Text(length=128)), not_null=False))
+""",
+    )

tests/test_generator_tables.py

@@ -181,6 +181,26 @@ def test_jsonb_default(generator: CodeGenerator) -> None:
     )
 
 
+@pytest.mark.parametrize("engine", ["postgresql"], indirect=["engine"])
+def test_json_default(generator: CodeGenerator) -> None:
+    Table("simple_items", generator.metadata, Column("json", postgresql.JSON))
+
+    validate_code(
+        generator.generate(),
+        """\
+        from sqlalchemy import Column, JSON, MetaData, Table
+
+        metadata = MetaData()
+
+
+        t_simple_items = Table(
+            'simple_items', metadata,
+            Column('json', JSON)
+        )
+        """,
+    )
+
+
 def test_enum_detection(generator: CodeGenerator) -> None:
     Table(
         "simple_items",