Render the PostgreSQL DOMAIN type in autogenerate

alembic/ddl/postgresql.py

@@ -63,6 +63,7 @@
     from sqlalchemy.dialects.postgresql.hstore import HSTORE
     from sqlalchemy.dialects.postgresql.json import JSON
     from sqlalchemy.dialects.postgresql.json import JSONB
+    from sqlalchemy.dialects.postgresql.named_types import DOMAIN
     from sqlalchemy.sql.elements import ClauseElement
     from sqlalchemy.sql.elements import ColumnElement
     from sqlalchemy.sql.elements import quoted_name
@@ -515,6 +516,38 @@ def _render_JSONB_type(
             ),
         )
 
+    def _render_DOMAIN_type(
+        self, type_: DOMAIN, autogen_context: AutogenContext
+    ) -> str:
+        prefix = _postgresql_autogenerate_prefix(autogen_context)
+        args = [
+            repr(render._ident(type_.name)),
+            render._repr_type(type_.data_type, autogen_context),
+        ]
+        if type_.collation is not None:
+            args.append("collation=%r" % type_.collation)
+        if type_.default is not None:
+            args.append(
+                "default=%s"
+                % render._render_potential_expr(
+                    type_.default, autogen_context, wrap_in_element=True
+                )
+            )
+        if type_.constraint_name is not None:
+            args.append("constraint_name=%r" % type_.constraint_name)
+        if type_.not_null:
+            args.append("not_null=True")
+        if type_.check is not None:
+            args.append(
+                "check=%s"
+                % render._render_potential_expr(
+                    type_.check, autogen_context, wrap_in_element=False
+                )
+            )
+        if type_.create_type is not True:
+            args.append("create_type=False")
+        return "%sDOMAIN(%s)" % (prefix, ", ".join(args))
+
 
 class PostgresqlColumnType(AlterColumn):
     def __init__(

docs/build/unreleased/1360.rst

@@ -0,0 +1,12 @@
+.. change::
+    :tags: bug, autogenerate, postgresql
+    :tickets: 1360
+
+    Fixed rendering of the PostgreSQL
+    :class:`~sqlalchemy.dialects.postgresql.DOMAIN` type in autogenerated
+    migration scripts.  Previously the type was rendered using ``repr()``,
+    which omitted the ``check``, ``not_null``, ``default``, ``collation``,
+    ``constraint_name`` and ``create_type`` arguments and did not apply a
+    dialect prefix to the underlying data type.  The full set of arguments
+    is now rendered and the underlying data type is rendered using the
+    standard type-rendering logic.

tests/test_postgresql.py

@@ -1361,6 +1361,45 @@ def test_jsonb_type(self):
             "postgresql.JSONB(astext_type=sa.Text())",
         )
 
+    @config.requirements.sqlalchemy_2
+    def test_domain_type(self):
+        """test #1360"""
+        from sqlalchemy.dialects.postgresql import CITEXT
+        from sqlalchemy.dialects.postgresql import DOMAIN
+
+        eq_ignore_whitespace(
+            autogenerate.render._repr_type(
+                DOMAIN("email", CITEXT(), check=r"value ~ '^my_.*$'"),
+                self.autogen_context,
+            ),
+            "postgresql.DOMAIN('email', postgresql.CITEXT(), "
+            "check=\"value ~ '^my_.*$'\")",
+        )
+
+    @config.requirements.sqlalchemy_2
+    def test_domain_type_full(self):
+        """test #1360"""
+        from sqlalchemy.dialects.postgresql import DOMAIN
+
+        eq_ignore_whitespace(
+            autogenerate.render._repr_type(
+                DOMAIN(
+                    "mydom",
+                    String(),
+                    collation="C",
+                    default="x",
+                    constraint_name="ck",
+                    not_null=True,
+                    check="value > 0",
+                    create_type=False,
+                ),
+                self.autogen_context,
+            ),
+            "postgresql.DOMAIN('mydom', sa.String(), collation='C', "
+            "default='x', constraint_name='ck', not_null=True, "
+            "check='value > 0', create_type=False)",
+        )
+
     def test_jsonb_expression_in_index(self):
         """test #1322"""