1 files changed, 69 insertions, 0 deletions
diff --git a/spec/rubocop/cop/migration/update_large_table_spec.rb b/spec/rubocop/cop/migration/update_large_table_spec.rb
new file mode 100644
index 00000000000..17b19e139e4
--- /dev/null
+++ b/spec/rubocop/cop/migration/update_large_table_spec.rb
@@ -0,0 +1,69 @@
+require 'spec_helper'
+
+require 'rubocop'
+require 'rubocop/rspec/support'
+
+require_relative '../../../../rubocop/cop/migration/update_large_table'
+
+describe RuboCop::Cop::Migration::UpdateLargeTable do
+  include CopHelper
+
+  subject(:cop) { described_class.new }
+
+  context 'in migration' do
+    before do
+      allow(cop).to receive(:in_migration?).and_return(true)
+    end
+
+    shared_examples 'large tables' do |update_method|
+      described_class::LARGE_TABLES.each do |table|
+        it "registers an offense for the #{table} table" do
+          inspect_source(cop, "#{update_method} :#{table}, :column, default: true")
+
+          aggregate_failures do
+            expect(cop.offenses.size).to eq(1)
+            expect(cop.offenses.map(&:line)).to eq([1])
+          end
+        end
+      end
+    end
+
+    context 'for the add_column_with_default method' do
+      include_examples 'large tables', 'add_column_with_default'
+    end
+
+    context 'for the update_column_in_batches method' do
+      include_examples 'large tables', 'update_column_in_batches'
+    end
+
+    it 'registers no offense for non-blacklisted tables' do
+      inspect_source(cop, "add_column_with_default :table, :column, default: true")
+
+      expect(cop.offenses).to be_empty
+    end
+
+    it 'registers no offense for non-blacklisted methods' do
+      table = described_class::LARGE_TABLES.sample
+
+      inspect_source(cop, "some_other_method :#{table}, :column, default: true")
+
+      expect(cop.offenses).to be_empty
+    end
+  end
+
+  context 'outside of migration' do
+    let(:table) { described_class::LARGE_TABLES.sample }
+
+    it 'registers no offense for add_column_with_default' do
+      inspect_source(cop, "add_column_with_default :#{table}, :column, default: true")
+
+      expect(cop.offenses).to be_empty
+    end
+
+    it 'registers no offense for update_column_in_batches' do
+      inspect_source(cop, "add_column_with_default :#{table}, :column, default: true")
+
+      expect(cop.offenses).to be_empty
+    end
+  end
+end