1 files changed, 83 insertions, 0 deletions
diff --git a/spec/lib/gitlab/database/schema_cache_with_renamed_table_spec.rb b/spec/lib/gitlab/database/schema_cache_with_renamed_table_spec.rb
new file mode 100644
index 00000000000..8c0c4155ccc
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+++ b/spec/lib/gitlab/database/schema_cache_with_renamed_table_spec.rb
@@ -0,0 +1,83 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::Database::SchemaCacheWithRenamedTable do
+  let(:old_model) do
+    Class.new(ActiveRecord::Base) do
+      self.table_name = 'projects'
+    end
+  end
+
+  let(:new_model) do
+    Class.new(ActiveRecord::Base) do
+      self.table_name = 'projects_new'
+    end
+  end
+
+  before do
+    stub_const('Gitlab::Database::TABLES_TO_BE_RENAMED', { 'projects' => 'projects_new' })
+  end
+
+  context 'when table is not renamed yet' do
+    before do
+      old_model.reset_column_information
+      ActiveRecord::Base.connection.schema_cache.clear!
+    end
+
+    it 'uses the original table to look up metadata' do
+      expect(old_model.primary_key).to eq('id')
+    end
+  end
+
+  context 'when table is renamed' do
+    before do
+      ActiveRecord::Base.connection.execute("ALTER TABLE projects RENAME TO projects_new")
+      ActiveRecord::Base.connection.execute("CREATE VIEW projects AS SELECT * FROM projects_new")
+
+      old_model.reset_column_information
+      ActiveRecord::Base.connection.schema_cache.clear!
+    end
+
+    it 'uses the renamed table to look up metadata' do
+      expect(old_model.primary_key).to eq('id')
+    end
+
+    it 'has primary key' do
+      expect(old_model.primary_key).to eq('id')
+      expect(old_model.primary_key).to eq(new_model.primary_key)
+    end
+
+    it 'has the same column definitions' do
+      expect(old_model.columns).to eq(new_model.columns)
+    end
+
+    it 'has the same indexes' do
+      indexes_for_old_table = ActiveRecord::Base.connection.schema_cache.indexes('projects')
+      indexes_for_new_table = ActiveRecord::Base.connection.schema_cache.indexes('projects_new')
+
+      expect(indexes_for_old_table).to eq(indexes_for_new_table)
+    end
+
+    it 'has the same column_hash' do
+      columns_hash_for_old_table = ActiveRecord::Base.connection.schema_cache.columns_hash('projects')
+      columns_hash_for_new_table = ActiveRecord::Base.connection.schema_cache.columns_hash('projects_new')
+
+      expect(columns_hash_for_old_table).to eq(columns_hash_for_new_table)
+    end
+
+    describe 'when the table behind a model is actually a view' do
+      let(:group) { create(:group) }
+      let(:project_attributes) { attributes_for(:project, namespace_id: group.id).except(:creator) }
+      let(:record) { old_model.create!(project_attributes) }
+
+      it 'can persist records' do
+        expect(record.reload.attributes).to eq(new_model.find(record.id).attributes)
+      end
+
+      it 'can find records' do
+        expect(old_model.find_by_id(record.id)).not_to be_nil
+      end
+    end
+  end
+end