`delete_records` nullifies `PolymorphicOneToMany` FKs before destroy, failing when FK is `NOT NULL`

[apacosta]

Description

We've been following the great work on polymorphic association fixes (related to #205 and #279) and wanted to flag another edge case we've run into.

We have a polymorphic association between models for "achievement evidence".

Simplified data structure:
Feedback → AchievementEvidence

AchievementEvidence:

• evidence_id and evidence_type stores the polymorphic parent (e.g. Feedback)
• achievement_progress_id for the progress record it is attached to

Environment

• forest_admin_rails 1.26.3
• Rails 7.x, Ruby 3.x, PostgreSQL

Reproduction

Schema:

create_table "achievement_evidences" do |t|
  t.string "evidence_type", null: false
  t.bigint "evidence_id",   null: false
  t.bigint "achievement_progress_id", null: false
end

Models:

class Feedback < ApplicationRecord
  has_many :achievement_evidences, as: :evidence, dependent: :destroy
end

class AchievementEvidence < ApplicationRecord
  belongs_to :evidence, polymorphic: true
end

Expected

Deleting a Feedback record via the ForestAdmin UI should destroy associated AchievementEvidence records. From the Rails console this works correctly:

Feedback.find(1).destroy
# DELETE FROM "achievement_evidences" WHERE "achievement_evidences"."evidence_type" = 'Feedback' AND "achievement_evidences"."evidence_id" = 1
# DELETE FROM "feedbacks" WHERE "feedbacks"."id" = 1

Actual

Deleting via the ForestAdmin UI fails with:

An error occurred when trying to delete feedback: Your data seems to be invalid:
Validation failed: Evidence is required, Evidence type is not included in the list.

From the logs, ForestAdmin is issuing an UPDATE to nullify the FK before calling destroy:

UPDATE "achievement_evidences" SET "evidence_id" = NULL, "evidence_type" = NULL
WHERE "achievement_evidences"."evidence_type" = 'Feedback' AND "achievement_evidences"."evidence_id" = 1

Since evidence_id is NOT NULL in our schema, this update fails validation before the destroy ever runs.

Happy to provide any additional details or help test a fix. Thanks for your time!

[bexchauveto]

Hello @apacosta 👋

Thank you for the feedback, I was able to reproduce the issue locally.
This PR #291 should fix this issue, can you test it before we can release it ?

Let us know if that resolves the issue on your side !

[apacosta]

Hi @bexchauveto thanks for the help,

Tested PR #291 locally and the fix is working as expected — deleting a parent record with NOT NULL polymorphic foreign keys now completes successfully. It solves the issue on our side. Thanks for the fix!

[forest-bot]

🎉 This issue has been resolved in version 1.27.1 🎉

The release is available on GitHub release

Your semantic-release bot 📦🚀