1 files changed, 139 insertions, 0 deletions
diff --git a/spec/lib/gitlab/database/bulk_update_spec.rb b/spec/lib/gitlab/database/bulk_update_spec.rb
new file mode 100644
index 00000000000..f2a7d6e69d8
--- /dev/null
+++ b/spec/lib/gitlab/database/bulk_update_spec.rb
@@ -0,0 +1,139 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::Database::BulkUpdate do
+  describe 'error states' do
+    let(:columns) { %i[title] }
+
+    let_it_be(:mapping) do
+      create_default(:user)
+      create_default(:project)
+
+      i_a, i_b = create_list(:issue, 2)
+
+      {
+        i_a  => { title: 'Issue a' },
+        i_b  => { title: 'Issue b' }
+      }
+    end
+
+    it 'does not raise errors on valid inputs' do
+      expect { described_class.execute(columns, mapping) }.not_to raise_error
+    end
+
+    it 'expects a non-empty list of column names' do
+      expect { described_class.execute([], mapping) }.to raise_error(ArgumentError)
+    end
+
+    it 'expects all columns to be symbols' do
+      expect { described_class.execute([1], mapping) }.to raise_error(ArgumentError)
+    end
+
+    it 'expects all columns to be valid columns on the tables' do
+      expect { described_class.execute([:foo], mapping) }.to raise_error(ArgumentError)
+    end
+
+    it 'refuses to set ID' do
+      expect { described_class.execute([:id], mapping) }.to raise_error(ArgumentError)
+    end
+
+    it 'expects a non-empty mapping' do
+      expect { described_class.execute(columns, []) }.to raise_error(ArgumentError)
+    end
+
+    it 'expects all map values to be Hash instances' do
+      bad_map = mapping.merge(build(:issue) => 2)
+
+      expect { described_class.execute(columns, bad_map) }.to raise_error(ArgumentError)
+    end
+  end
+
+  it 'is possible to update all objects in a single query' do
+    users = create_list(:user, 3)
+    mapping = users.zip(%w(foo bar baz)).to_h do |u, name|
+      [u, { username: name, admin: true }]
+    end
+
+    expect do
+      described_class.execute(%i[username admin], mapping)
+    end.not_to exceed_query_limit(1)
+
+    # We have optimistically updated the values
+    expect(users).to all(be_admin)
+    expect(users.map(&:username)).to eq(%w(foo bar baz))
+
+    users.each(&:reset)
+
+    # The values are correct on reset
+    expect(users).to all(be_admin)
+    expect(users.map(&:username)).to eq(%w(foo bar baz))
+  end
+
+  it 'is possible to update heterogeneous sets' do
+    create_default(:user)
+    create_default(:project)
+
+    mr_a = create(:merge_request)
+    i_a, i_b = create_list(:issue, 2)
+
+    mapping = {
+      mr_a => { title: 'MR a' },
+      i_a  => { title: 'Issue a' },
+      i_b  => { title: 'Issue b' }
+    }
+
+    expect do
+      described_class.execute(%i[title], mapping)
+    end.not_to exceed_query_limit(2)
+
+    expect([mr_a, i_a, i_b].map { |x| x.reset.title })
+      .to eq(['MR a', 'Issue a', 'Issue b'])
+  end
+
+  shared_examples 'basic functionality' do
+    it 'sets multiple values' do
+      create_default(:user)
+      create_default(:project)
+
+      i_a, i_b = create_list(:issue, 2)
+
+      mapping = {
+        i_a  => { title: 'Issue a' },
+        i_b  => { title: 'Issue b' }
+      }
+
+      described_class.execute(%i[title], mapping)
+
+      expect([i_a, i_b].map { |x| x.reset.title })
+        .to eq(['Issue a', 'Issue b'])
+    end
+  end
+
+  include_examples 'basic functionality'
+
+  context 'when prepared statements are configured differently to the normal test environment' do
+    # rubocop: disable RSpec/LeakyConstantDeclaration
+    # This cop is disabled because you cannot call establish_connection on
+    # an anonymous class.
+    class ActiveRecordBasePreparedStatementsInverted < ActiveRecord::Base
+      def self.abstract_class?
+        true # So it gets its own connection
+      end
+    end
+    # rubocop: enable RSpec/LeakyConstantDeclaration
+
+    before_all do
+      c = ActiveRecord::Base.connection.instance_variable_get(:@config)
+      inverted = c.merge(prepared_statements: !ActiveRecord::Base.connection.prepared_statements)
+      ActiveRecordBasePreparedStatementsInverted.establish_connection(inverted)
+    end
+
+    before do
+      allow(ActiveRecord::Base).to receive(:connection_specification_name)
+        .and_return(ActiveRecordBasePreparedStatementsInverted.connection_specification_name)
+    end
+
+    include_examples 'basic functionality'
+  end
+end