check for MemberExpr looking for column argument

Fixed issue in MyPy extension which crashed on detecting the type of a
:class:`.Column` if the type were given with a module prefix like
``sa.Integer()``.

Fixes: sqlalchemy/sqlalchemy2-stubs/#2
Change-Id: I71f53a6ced501ae144e28ce255cf3f50ea2b2e84

1 files changed, 33 insertions, 0 deletions

diff --git a/test/ext/mypy/files/sa_module_prefix.py b/test/ext/mypy/files/sa_module_prefix.py
new file mode 100644
index 000000000..a37ae6b06
--- /dev/null
+++ b/test/ext/mypy/files/sa_module_prefix.py
@@ -0,0 +1,33 @@
+from typing import List
+from typing import Optional
+
+import sqlalchemy as sa
+from sqlalchemy import orm as saorm
+
+
+Base = saorm.declarative_base()
+
+
+class B(Base):
+    __tablename__ = "b"
+    id = sa.Column(sa.Integer, primary_key=True)
+    a_id: int = sa.Column(sa.ForeignKey("a.id"))
+    data = sa.Column(sa.String)
+
+    a: Optional["A"] = saorm.relationship("A", back_populates="bs")
+
+
+class A(Base):
+    __tablename__ = "a"
+
+    id = sa.Column(sa.Integer, primary_key=True)
+    data = sa.Column(sa.String)
+    bs = saorm.relationship(B, uselist=True, back_populates="a")
+
+
+a1 = A(bs=[B(data="b"), B(data="b")])
+
+x: List[B] = a1.bs
+
+
+b1 = B(a=A())