Extract convert_to_bigint_column migration helper

We do a lot of "#{column})_convert_to_bigint", this extracts it in a
helper method, and updates rest of the code to use it.

https://gitlab.com/gitlab-org/gitlab/-/merge_requests/59957.

lib/gitlab/database/migration_helpers.rb

@@ -905,6 +905,10 @@ module Gitlab
         end
       end
 
+      def convert_to_bigint_column(column)
+        "#{column}_convert_to_bigint"
+      end
+
       # Initializes the conversion of a set of integer columns to bigint
       #
       # It can be used for converting both a Primary Key and any Foreign Keys
@@ -948,7 +952,7 @@ module Gitlab
 
         check_trigger_permissions!(table)
 
-        conversions = columns.to_h { |column| [column, "#{column}_convert_to_bigint"] }
+        conversions = columns.to_h { |column| [column, convert_to_bigint_column(column)] }
 
         with_lock_retries do
           conversions.each do |(source_column, temporary_name)|
@@ -975,7 +979,7 @@ module Gitlab
       # columns - The name, or array of names, of the column(s) that we're converting to bigint.
       def revert_initialize_conversion_of_integer_to_bigint(table, columns)
         columns = Array.wrap(columns)
-        temporary_columns = columns.map { |column| "#{column}_convert_to_bigint" }
+        temporary_columns = columns.map { |column| convert_to_bigint_column(column) }
 
         trigger_name = rename_trigger_name(table, columns, temporary_columns)
         remove_rename_triggers_for_postgresql(table, trigger_name)
@@ -1039,7 +1043,7 @@ module Gitlab
         conversions = Array.wrap(columns).to_h do |column|
           raise ArgumentError, "Column #{column} does not exist on #{table}" unless column_exists?(table, column)
 
-          temporary_name = "#{column}_convert_to_bigint"
+          temporary_name = convert_to_bigint_column(column)
           raise ArgumentError, "Column #{temporary_name} does not exist on #{table}" unless column_exists?(table, temporary_name)
 
           [column, temporary_name]
@@ -1075,7 +1079,7 @@ module Gitlab
           job_class_name: 'CopyColumnUsingBackgroundMigrationJob',
           table_name: table,
           column_name: primary_key,
-          job_arguments: [columns, columns.map { |c| "#{c}_convert_to_bigint" }].to_json
+          job_arguments: [columns, columns.map { |column| convert_to_bigint_column(column) }].to_json
         ])
 
         execute("DELETE FROM batched_background_migrations WHERE #{conditions}")

spec/lib/gitlab/background_migration/copy_column_using_background_migration_job_spec.rb

@@ -8,6 +8,10 @@ RSpec.describe Gitlab::BackgroundMigration::CopyColumnUsingBackgroundMigrationJo
   let(:sub_batch_size) { 1000 }
   let(:pause_ms) { 0 }
 
+  let(:helpers) do
+    ActiveRecord::Migration.new.extend(Gitlab::Database::MigrationHelpers)
+  end
+
   before do
     ActiveRecord::Base.connection.execute(<<~SQL)
       CREATE TABLE #{table_name}
@@ -15,8 +19,8 @@ RSpec.describe Gitlab::BackgroundMigration::CopyColumnUsingBackgroundMigrationJo
        id integer NOT NULL,
        name character varying,
        fk integer NOT NULL,
-       id_convert_to_bigint bigint DEFAULT 0 NOT NULL,
-       fk_convert_to_bigint bigint DEFAULT 0 NOT NULL,
+       #{helpers.convert_to_bigint_column(:id)} bigint DEFAULT 0 NOT NULL,
+       #{helpers.convert_to_bigint_column(:fk)} bigint DEFAULT 0 NOT NULL,
        name_convert_to_text text DEFAULT 'no name'
       );
     SQL
@@ -41,18 +45,20 @@ RSpec.describe Gitlab::BackgroundMigration::CopyColumnUsingBackgroundMigrationJo
     let(:migration_class) { described_class.name }
 
     it 'copies all primary keys in range' do
-      copy_columns.perform(12, 15, table_name, 'id', sub_batch_size, pause_ms, 'id', 'id_convert_to_bigint')
+      temporary_column = helpers.convert_to_bigint_column(:id)
+      copy_columns.perform(12, 15, table_name, 'id', sub_batch_size, pause_ms, 'id', temporary_column)
 
-      expect(test_table.where('id = id_convert_to_bigint').pluck(:id)).to contain_exactly(12, 15)
-      expect(test_table.where(id_convert_to_bigint: 0).pluck(:id)).to contain_exactly(11, 19)
+      expect(test_table.where("id = #{temporary_column}").pluck(:id)).to contain_exactly(12, 15)
+      expect(test_table.where(temporary_column => 0).pluck(:id)).to contain_exactly(11, 19)
       expect(test_table.all.count).to eq(4)
     end
 
     it 'copies all foreign keys in range' do
-      copy_columns.perform(10, 14, table_name, 'id', sub_batch_size, pause_ms, 'fk', 'fk_convert_to_bigint')
+      temporary_column = helpers.convert_to_bigint_column(:fk)
+      copy_columns.perform(10, 14, table_name, 'id', sub_batch_size, pause_ms, 'fk', temporary_column)
 
-      expect(test_table.where('fk = fk_convert_to_bigint').pluck(:id)).to contain_exactly(11, 12)
-      expect(test_table.where(fk_convert_to_bigint: 0).pluck(:id)).to contain_exactly(15, 19)
+      expect(test_table.where("fk = #{temporary_column}").pluck(:id)).to contain_exactly(11, 12)
+      expect(test_table.where(temporary_column => 0).pluck(:id)).to contain_exactly(15, 19)
       expect(test_table.all.count).to eq(4)
     end
 
@@ -68,18 +74,20 @@ RSpec.describe Gitlab::BackgroundMigration::CopyColumnUsingBackgroundMigrationJo
 
     it 'copies multiple columns when given' do
       columns_to_copy_from = %w[id fk]
-      columns_to_copy_to = %w[id_convert_to_bigint fk_convert_to_bigint]
+      id_tmp_column = helpers.convert_to_bigint_column('id')
+      fk_tmp_column = helpers.convert_to_bigint_column('fk')
+      columns_to_copy_to = [id_tmp_column, fk_tmp_column]
 
       subject.perform(10, 15, table_name, 'id', sub_batch_size, pause_ms, columns_to_copy_from, columns_to_copy_to)
 
-      expect(test_table.where('id = id_convert_to_bigint AND fk = fk_convert_to_bigint').pluck(:id)).to contain_exactly(11, 12, 15)
-      expect(test_table.where(id_convert_to_bigint: 0).where(fk_convert_to_bigint: 0).pluck(:id)).to contain_exactly(19)
+      expect(test_table.where("id = #{id_tmp_column} AND fk = #{fk_tmp_column}").pluck(:id)).to contain_exactly(11, 12, 15)
+      expect(test_table.where(id_tmp_column => 0).where(fk_tmp_column => 0).pluck(:id)).to contain_exactly(19)
       expect(test_table.all.count).to eq(4)
     end
 
     it 'raises error when number of source and target columns does not match' do
       columns_to_copy_from = %w[id fk]
-      columns_to_copy_to = %w[id_convert_to_bigint]
+      columns_to_copy_to = [helpers.convert_to_bigint_column(:id)]
 
       expect do
         subject.perform(10, 15, table_name, 'id', sub_batch_size, pause_ms, columns_to_copy_from, columns_to_copy_to)

spec/lib/gitlab/database/migration_helpers_spec.rb

@@ -1703,10 +1703,16 @@ RSpec.describe Gitlab::Database::MigrationHelpers do
     end
   end
 
+  describe '#convert_to_bigint_column' do
+    it 'returns the name of the temporary column used to convert to bigint' do
+      expect(model.convert_to_bigint_column(:id)).to eq('id_convert_to_bigint')
+    end
+  end
+
   describe '#initialize_conversion_of_integer_to_bigint' do
     let(:table) { :test_table }
     let(:column) { :id }
-    let(:tmp_column) { "#{column}_convert_to_bigint" }
+    let(:tmp_column) { model.convert_to_bigint_column(column) }
 
     before do
       model.create_table table, id: false do |t|
@@ -1775,11 +1781,7 @@ RSpec.describe Gitlab::Database::MigrationHelpers do
     context 'when multiple columns are given' do
       it 'creates the correct columns and installs the trigger' do
         columns_to_convert = %i[id non_nullable_column nullable_column]
-        temporary_columns = %w[
-          id_convert_to_bigint
-          non_nullable_column_convert_to_bigint
-          nullable_column_convert_to_bigint
-        ]
+        temporary_columns = columns_to_convert.map { |column| model.convert_to_bigint_column(column) }
 
         expect(model).to receive(:add_column).with(table, temporary_columns[0], :bigint, default: 0, null: false)
         expect(model).to receive(:add_column).with(table, temporary_columns[1], :bigint, default: 0, null: false)
@@ -1808,11 +1810,12 @@ RSpec.describe Gitlab::Database::MigrationHelpers do
       let(:columns) { :id }
 
       it 'removes column, trigger, and function' do
-        trigger_name = model.rename_trigger_name(table, :id, :id_convert_to_bigint)
+        temporary_column = model.convert_to_bigint_column(:id)
+        trigger_name = model.rename_trigger_name(table, :id, temporary_column)
 
         model.revert_initialize_conversion_of_integer_to_bigint(table, columns)
 
-        expect(model.column_exists?(table, :id_convert_to_bigint)).to eq(false)
+        expect(model.column_exists?(table, temporary_column)).to eq(false)
         expect_trigger_not_to_exist(table, trigger_name)
         expect_function_not_to_exist(trigger_name)
       end
@@ -1822,12 +1825,14 @@ RSpec.describe Gitlab::Database::MigrationHelpers do
       let(:columns) { [:id, :other_id] }
 
       it 'removes column, trigger, and function' do
-        trigger_name = model.rename_trigger_name(table, columns, [:id_convert_to_bigint, :other_id_convert_to_bigint])
+        temporary_columns = columns.map { |column| model.convert_to_bigint_column(column) }
+        trigger_name = model.rename_trigger_name(table, columns, temporary_columns)
 
         model.revert_initialize_conversion_of_integer_to_bigint(table, columns)
 
-        expect(model.column_exists?(table, :id_convert_to_bigint)).to eq(false)
-        expect(model.column_exists?(table, :other_id_convert_to_bigint)).to eq(false)
+        temporary_columns.each do |column|
+          expect(model.column_exists?(table, column)).to eq(false)
+        end
         expect_trigger_not_to_exist(table, trigger_name)
         expect_function_not_to_exist(trigger_name)
       end
@@ -1837,7 +1842,7 @@ RSpec.describe Gitlab::Database::MigrationHelpers do
   describe '#backfill_conversion_of_integer_to_bigint' do
     let(:table) { :_test_backfill_table }
     let(:column) { :id }
-    let(:tmp_column) { "#{column}_convert_to_bigint" }
+    let(:tmp_column) { model.convert_to_bigint_column(column) }
 
     before do
       model.create_table table, id: false do |t|
@@ -1915,14 +1920,14 @@ RSpec.describe Gitlab::Database::MigrationHelpers do
             interval: 120,
             batch_size: 2,
             sub_batch_size: 1,
-            job_arguments: [[column.to_s], ["#{column}_convert_to_bigint"]]
+            job_arguments: [[column.to_s], [model.convert_to_bigint_column(column)]]
           )
         end
       end
 
       context 'when multiple columns are being converted' do
         let(:other_column) { :other_id }
-        let(:other_tmp_column) { "#{other_column}_convert_to_bigint" }
+        let(:other_tmp_column) { model.convert_to_bigint_column(other_column) }
         let(:columns) { [column, other_column] }
 
         it 'creates the batched migration tracking record' do