1 files changed, 145 insertions, 0 deletions
diff --git a/spec/tooling/danger/ignored_model_columns_spec.rb b/spec/tooling/danger/ignored_model_columns_spec.rb
new file mode 100644
index 00000000000..737b6cce077
--- /dev/null
+++ b/spec/tooling/danger/ignored_model_columns_spec.rb
@@ -0,0 +1,145 @@
+# frozen_string_literal: true
+
+require 'danger'
+require 'gitlab/dangerfiles/spec_helper'
+
+require_relative '../../../tooling/danger/ignored_model_columns'
+require_relative '../../../tooling/danger/project_helper'
+
+RSpec.describe Tooling::Danger::IgnoredModelColumns, feature_category: :tooling do
+  subject(:ignored_model_columns) { fake_danger.new(helper: fake_helper) }
+
+  let(:fake_danger) { DangerSpecHelper.fake_danger.include(described_class) }
+  let(:fake_project_helper) { instance_double(Tooling::Danger::ProjectHelper) }
+  let(:comment) { described_class::COMMENT.chomp }
+  let(:file_diff) do
+    File.read(File.expand_path("../fixtures/#{fixture}", __dir__)).split("\n")
+  end
+
+  include_context "with dangerfile"
+
+  describe '#add_comment_for_ignored_model_columns' do
+    let(:file_lines) { file_diff.map { |line| line.delete_prefix('+').delete_prefix('-') } }
+
+    before do
+      allow(ignored_model_columns).to receive(:project_helper).and_return(fake_project_helper)
+      allow(ignored_model_columns.project_helper).to receive(:file_lines).and_return(file_lines)
+      allow(ignored_model_columns.helper).to receive(:all_changed_files).and_return([filename])
+      allow(ignored_model_columns.helper).to receive(:changed_lines).with(filename).and_return(file_diff)
+    end
+
+    context 'when table column is renamed in a regular migration' do
+      let(:filename) { 'db/migrate/rename_my_column_migration.rb' }
+      let(:fixture) { 'rename_column_migration.txt' }
+      let(:matching_lines) { [7, 11, 15, 19, 23, 27, 31, 35, 39] }
+
+      it 'adds comment at the correct line' do
+        matching_lines.each do |line_number|
+          expect(ignored_model_columns).to receive(:markdown).with("\n#{comment}", file: filename, line: line_number)
+        end
+
+        ignored_model_columns.add_comment_for_ignored_model_columns
+      end
+    end
+
+    context 'when table column is renamed in a post migration' do
+      let(:filename) { 'db/post_migrate/remove_column_migration.rb' }
+      let(:fixture) { 'remove_column_migration.txt' }
+      let(:matching_lines) { [7, 8, 16, 24, 32, 40, 48, 56, 64, 72] }
+
+      it 'adds comment at the correct line' do
+        matching_lines.each do |line_number|
+          expect(ignored_model_columns).to receive(:markdown).with("\n#{comment}", file: filename, line: line_number)
+        end
+
+        ignored_model_columns.add_comment_for_ignored_model_columns
+      end
+    end
+
+    context 'when table cleanup is performed in a post migration' do
+      let(:filename) { 'db/post_migrate/cleanup_conversion_big_int_migration.rb' }
+      let(:fixture) { 'cleanup_conversion_migration.txt' }
+      let(:matching_lines) { [7, 11, 15, 19, 23, 27, 31, 35, 39] }
+
+      it 'adds comment at the correct line' do
+        matching_lines.each do |line_number|
+          expect(ignored_model_columns).to receive(:markdown).with("\n#{comment}", file: filename, line: line_number)
+        end
+
+        ignored_model_columns.add_comment_for_ignored_model_columns
+      end
+    end
+
+    context 'when a regular migration does not rename table column' do
+      let(:filename) { 'db/migrate/my_migration.rb' }
+      let(:file_diff) do
+        [
+          "+    undo_cleanup_concurrent_column_rename(:my_table, :old_column, :new_column)",
+          "-    cleanup_concurrent_column_rename(:my_table, :new_column, :old_column)"
+        ]
+      end
+
+      let(:file_lines) do
+        [
+          '  def up',
+          '    undo_cleanup_concurrent_column_rename(:my_table, :old_column, :new_column)',
+          '  end'
+        ]
+      end
+
+      it 'does not add comment' do
+        expect(ignored_model_columns).not_to receive(:markdown)
+
+        ignored_model_columns.add_comment_for_ignored_model_columns
+      end
+    end
+
+    context 'when a post migration does not remove table column' do
+      let(:filename) { 'db/migrate/my_migration.rb' }
+      let(:file_diff) do
+        [
+          "+    add_column(:my_table, :my_column, :type)",
+          "-    remove_column(:my_table, :my_column)"
+        ]
+      end
+
+      let(:file_lines) do
+        [
+          '  def up',
+          '    add_column(:my_table, :my_column, :type)',
+          '  end'
+        ]
+      end
+
+      it 'does not add comment' do
+        expect(ignored_model_columns).not_to receive(:markdown)
+
+        ignored_model_columns.add_comment_for_ignored_model_columns
+      end
+    end
+
+    context 'when a post migration does not convert table column' do
+      let(:filename) { 'db/migrate/my_migration.rb' }
+      let(:file_diff) do
+        [
+          "+    restore_conversion_of_integer_to_bigint(TABLE, COLUMNS)",
+          "-    cleanup_conversion_of_integer_to_bigint(TABLE, COLUMNS)"
+        ]
+      end
+
+      let(:file_lines) do
+        [
+          '  def up',
+          '    cleanup_conversion_of_integer_to_bigint(TABLE, COLUMNS)',
+          '  end'
+        ]
+      end
+
+      it 'does not add comment' do
+        expect(ignored_model_columns).not_to receive(:markdown)
+
+        ignored_model_columns.add_comment_for_ignored_model_columns
+      end
+    end
+  end
+end