Make integrations type_new trigger null-safe

This adjusts the existing DB trigger to:

- work in both directions
- be null safe

Changelog: changed

db/migrate/20220211214605_update_integrations_trigger_type_new_on_insert_null_safe.rb

+# frozen_string_literal: true
+
+class UpdateIntegrationsTriggerTypeNewOnInsertNullSafe < Gitlab::Database::Migration[1.0]
+  include Gitlab::Database::SchemaHelpers
+
+  FUNCTION_NAME = 'integrations_set_type_new'
+
+  def up
+    # Update `type_new` dynamically based on `type`, if `type_new` is null
+    # and `type` dynamically based on `type_new`, if `type` is null.
+    #
+    # The old class names are in the format `AbcService`, and the new ones `Integrations::Abc`.
+    create_trigger_function(FUNCTION_NAME, replace: true) do
+      <<~SQL.squish
+        UPDATE integrations
+           SET type_new = COALESCE(NEW.type_new, regexp_replace(NEW.type, '\\A(.+)Service\\Z', 'Integrations::\\1'))
+             , type     = COALESCE(NEW.type, regexp_replace(NEW.type_new, '\\AIntegrations::(.+)\\Z', '\\1Service'))
+        WHERE integrations.id = NEW.id;
+        RETURN NULL;
+      SQL
+    end
+  end
+
+  def down
+    # Update `type_new` dynamically based on `type`.
+    #
+    # The old class names are in the format `AbcService`, and the new ones `Integrations::Abc`.
+    create_trigger_function(FUNCTION_NAME, replace: true) do
+      <<~SQL
+        UPDATE integrations SET type_new = regexp_replace(NEW.type, '\\A(.+)Service\\Z', 'Integrations::\\1')
+        WHERE integrations.id = NEW.id;
+        RETURN NULL;
+      SQL
+    end
+  end
+end

db/schema_migrations/20220211214605

+add5ee0b8e090ba740ce738f66ea4f741485a0c84728fecfa5b0488564d55536
\ No newline at end of file

db/structure.sql

@@ -93,10 +93,7 @@ CREATE FUNCTION integrations_set_type_new() RETURNS trigger
     LANGUAGE plpgsql
     AS $$
 BEGIN
-UPDATE integrations SET type_new = regexp_replace(NEW.type, '\A(.+)Service\Z', 'Integrations::\1')
-WHERE integrations.id = NEW.id;
-RETURN NULL;
-
+UPDATE integrations SET type_new = COALESCE(NEW.type_new, regexp_replace(NEW.type, '\A(.+)Service\Z', 'Integrations::\1')) , type = COALESCE(NEW.type, regexp_replace(NEW.type_new, '\AIntegrations::(.+)\Z', '\1Service')) WHERE integrations.id = NEW.id; RETURN NULL;
 END
 $$;
 

spec/migrations/20220211214605_update_integrations_trigger_type_new_on_insert_null_safe_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+require_migration!
+
+RSpec.describe UpdateIntegrationsTriggerTypeNewOnInsertNullSafe, :migration do
+  let(:integrations) { table(:integrations) }
+
+  before do
+    migrate!
+  end
+
+  it 'leaves defined values alone' do
+    record = integrations.create!(type: 'XService', type_new: 'Integrations::Y')
+
+    expect(integrations.find(record.id)).to have_attributes(type: 'XService', type_new: 'Integrations::Y')
+  end
+
+  it 'keeps type_new synchronized with type' do
+    record = integrations.create!(type: 'AbcService', type_new: nil)
+
+    expect(integrations.find(record.id)).to have_attributes(
+      type: 'AbcService',
+      type_new: 'Integrations::Abc'
+    )
+  end
+
+  it 'keeps type synchronized with type_new' do
+    record = integrations.create!(type: nil, type_new: 'Integrations::Abc')
+
+    expect(integrations.find(record.id)).to have_attributes(
+      type: 'AbcService',
+      type_new: 'Integrations::Abc'
+    )
+  end
+end