From ac9c649ecb6904696699d92e3254c919b25d7738 Mon Sep 17 00:00:00 2001
From: "Ernest W. Durbin III" <ewdurbin@gmail.com>
Date: Thu, 20 Feb 2020 17:20:55 -0500
Subject: [PATCH] CASCADE deletes from Project/Release/File to Verdicts (#7418)

---
 warehouse/malware/models.py                   |  9 +-
 ...e_cascade_deletes_from_project_release_.py | 92 +++++++++++++++++++
 2 files changed, 98 insertions(+), 3 deletions(-)
 create mode 100644 warehouse/migrations/versions/f47d2f06c13e_cascade_deletes_from_project_release_.py

diff --git a/warehouse/malware/models.py b/warehouse/malware/models.py
index e4f56fcf851a..45aa63ee17c2 100644
--- a/warehouse/malware/models.py
+++ b/warehouse/malware/models.py
@@ -147,9 +147,12 @@ class MalwareVerdict(db.Model):
         nullable=False,
         index=True,
     )
-    file_id = Column(ForeignKey("release_files.id"), nullable=True)
-    release_id = Column(ForeignKey("releases.id"), nullable=True)
-    project_id = Column(ForeignKey("projects.id"), nullable=True)
+    # TODO: When GH-4440 is resolved, we should remove these CASCADEs to ensure that an
+    #       auditable history of malware check verdicts remain in the event that a
+    #       Project, Release, or File is removed by it's maintainers.
+    file_id = Column(ForeignKey("release_files.id", ondelete="CASCADE"), nullable=True)
+    release_id = Column(ForeignKey("releases.id", ondelete="CASCADE",), nullable=True)
+    project_id = Column(ForeignKey("projects.id", ondelete="CASCADE",), nullable=True)
     classification = Column(
         Enum(VerdictClassification, values_callable=lambda x: [e.value for e in x]),
         nullable=False,
diff --git a/warehouse/migrations/versions/f47d2f06c13e_cascade_deletes_from_project_release_.py b/warehouse/migrations/versions/f47d2f06c13e_cascade_deletes_from_project_release_.py
new file mode 100644
index 000000000000..7a3cd3ade27f
--- /dev/null
+++ b/warehouse/migrations/versions/f47d2f06c13e_cascade_deletes_from_project_release_.py
@@ -0,0 +1,92 @@
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""
+Cascade deletes from Project/Release/File to Verdicts
+
+Revision ID: f47d2f06c13e
+Revises: 061ff3d24c22
+Create Date: 2020-02-20 17:28:36.194480
+"""
+
+from alembic import op
+
+revision = "f47d2f06c13e"
+down_revision = "061ff3d24c22"
+
+
+def upgrade():
+    op.drop_constraint(
+        "malware_verdicts_project_id_fkey", "malware_verdicts", type_="foreignkey"
+    )
+    op.drop_constraint(
+        "malware_verdicts_release_id_fkey", "malware_verdicts", type_="foreignkey"
+    )
+    op.drop_constraint(
+        "malware_verdicts_file_id_fkey", "malware_verdicts", type_="foreignkey"
+    )
+    op.create_foreign_key(
+        "malware_verdicts_project_id_fkey",
+        "malware_verdicts",
+        "projects",
+        ["project_id"],
+        ["id"],
+        ondelete="CASCADE",
+    )
+    op.create_foreign_key(
+        "malware_verdicts_release_id_fkey",
+        "malware_verdicts",
+        "releases",
+        ["release_id"],
+        ["id"],
+        ondelete="CASCADE",
+    )
+    op.create_foreign_key(
+        "malware_verdicts_file_id_fkey",
+        "malware_verdicts",
+        "release_files",
+        ["file_id"],
+        ["id"],
+        ondelete="CASCADE",
+    )
+
+
+def downgrade():
+    op.drop_constraint(
+        "malware_verdicts_file_id_fkey", "malware_verdicts", type_="foreignkey"
+    )
+    op.drop_constraint(
+        "malware_verdicts_release_id_fkey", "malware_verdicts", type_="foreignkey"
+    )
+    op.drop_constraint(
+        "malware_verdicts_project_id_fkey", "malware_verdicts", type_="foreignkey"
+    )
+    op.create_foreign_key(
+        "malware_verdicts_file_id_fkey",
+        "malware_verdicts",
+        "release_files",
+        ["file_id"],
+        ["id"],
+    )
+    op.create_foreign_key(
+        "malware_verdicts_release_id_fkey",
+        "malware_verdicts",
+        "releases",
+        ["release_id"],
+        ["id"],
+    )
+    op.create_foreign_key(
+        "malware_verdicts_project_id_fkey",
+        "malware_verdicts",
+        "projects",
+        ["project_id"],
+        ["id"],
+    )