Add acts_as_paranoid test coverage (#6862)

* Add acts_as_paranoid test coverage and soft-deleted model shared example

Add specs to ensure all paranoid models have proper unique index conditions
and include the soft-deleted model shared example. Add shared example for
reusable soft-delete behavior testing and described_class_factory helper.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix lint

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: compwron

spec/models/acts_as_paranoid_spec.rb

@@ -0,0 +1,34 @@
+require "rails_helper"
+
+RSpec.describe "acts_as_paranoid" do
+  let(:currently_probably_buggy_classes_ignored) do
+    %w[]
+  end
+  let(:allows_multiple_deleted) { "(deleted_at IS NULL)" }
+
+  it "checks that all activerecord models using acts_as_paranoid have the deleted exclusions on unique indexes" do
+    errors = []
+    found_ignored_error_indexes = []
+    Zeitwerk::Loader.eager_load_all
+    expect(ApplicationRecord.descendants.count).to be >= 54 # make sure we are actually testing all model classes
+    ApplicationRecord.descendants.each do |clazz|
+      next if clazz.abstract_class?
+      next unless clazz.paranoid?
+      unique_indexes = ApplicationRecord.connection_pool.with_connection do |connection|
+        connection.indexes(clazz.table_name).select(&:unique)
+      end
+      unique_indexes.each do |idx|
+        next if idx.columns == ["external_id"] # it is ok for external_id to be unique
+        if currently_probably_buggy_classes_ignored.include?(idx.name)
+          found_ignored_error_indexes << idx.name
+          next
+        end
+        unless idx.where&.include?(allows_multiple_deleted)
+          errors << "#{idx.name} on #{clazz} uses acts_as_paranoid but has a unique index without #{allows_multiple_deleted} but it does have: #{idx.where}"
+        end
+      end
+    end
+    expect(errors).to be_empty
+    expect(found_ignored_error_indexes).to match_array(currently_probably_buggy_classes_ignored)
+  end
+end

spec/models/soft_deleted_model_shared_example_coverage_spec.rb

@@ -0,0 +1,45 @@
+require "rails_helper"
+
+RSpec.describe "soft-deleted model shared example coverage" do
+  let(:skip_classes) do
+    %w[]
+  end
+
+  let(:todo_currently_missing_specs) do
+    %w[
+      ContactTopicAnswer
+      CaseContact
+    ]
+  end
+
+  it "checks that all acts_as_paranoid models have specs that include the soft-deleted model shared example" do
+    missing = []
+    Zeitwerk::Loader.eager_load_all
+
+    ApplicationRecord.descendants.each do |clazz|
+      next if clazz.abstract_class?
+      next unless clazz.paranoid?
+      next if skip_classes.include?(clazz.name)
+      next if todo_currently_missing_specs.include?(clazz.name)
+
+      source_file = Object.const_source_location(clazz.name)&.first
+      next unless source_file
+
+      spec_file = source_file
+        .sub(%r{/app/models/}, "/spec/models/")
+        .sub(/\.rb$/, "_spec.rb")
+
+      unless File.exist?(spec_file)
+        missing << "#{clazz.name}: spec file not found (expected #{spec_file})"
+        next
+      end
+
+      contents = File.read(spec_file)
+      unless contents.include?('"a soft-deleted model"')
+        missing << clazz.name.to_s
+      end
+    end
+
+    expect(missing).to be_empty, "The following paranoid models are missing the shared example:\n#{missing.join("\n")}"
+  end
+end

spec/support/factory_bot.rb

@@ -1,5 +1,9 @@
 # frozen_string_literal: true
 
+def described_class_factory
+  described_class.name.gsub("::", "").underscore
+end
+
 RSpec.configure do |config|
   config.include FactoryBot::Syntax::Methods
 

spec/support/shared_examples/soft_deleted_model.rb

@@ -0,0 +1,34 @@
+RSpec.shared_examples_for "a soft-deleted model" do |skip_ignores_deleted_records_in_validations_check: false, skip_deleted_at_index_check: false|
+  # for usage with acts_as_paranoid models
+
+  it { is_expected.to have_db_column(:deleted_at) }
+
+  unless skip_deleted_at_index_check
+    it { is_expected.to have_db_index(:deleted_at) }
+  end
+
+  it "cannot be found, by default" do
+    model ||= create(described_class_factory)
+    model.destroy!
+    expect(described_class.find_by(id: model.id)).to be_nil
+  end
+
+  it "returned when unscoped" do
+    model ||= create(described_class_factory)
+    model.destroy!
+    expect(described_class.unscoped.find_by(id: model.id)).to be_present
+  end
+
+  context "uniqueness" do
+    it "ignores deleted records in validations" do
+      unless skip_ignores_deleted_records_in_validations_check
+        obj = create(described_class_factory)
+        new_obj = obj.dup
+        expect(new_obj).not_to be_valid
+        obj.destroy!
+        expect(new_obj).to be_valid
+        expect { new_obj.save! }.not_to raise_exception
+      end
+    end
+  end
+end