has_aux_table/spec/loading_optimizations_spec.rb

# typed: false
# frozen_string_literal: true

require "spec_helper"

RSpec.describe "loading optimizations" do
  context "cars table" do
    before do
      Car.create!(name: "Toyota Camry", fuel_type: "gasoline", engine_size: 2.0)
      Car.create!(name: "Toyota Prius", fuel_type: "hybrid", engine_size: 1.5)
      Car.create!(
        name: "Toyota Corolla",
        fuel_type: "electric",
        engine_size: 1.8
      )
    end

    shared_examples "queries only the aux table" do
      it "queries only the aux table" do
        expect(queries.length).to eq(1)
        expect(queries.first).not_to include("JOIN")
        expect(queries.first).to match(/\bvehicles_car_aux\b/)
        expect(queries.first).not_to match(/\bvehicles\b/)
      end
    end

    shared_examples "queries both tables" do
      it "queries both tables" do
        expect(queries.length).to eq(1)
        expect(queries.first).to include("JOIN")
        expect(queries.first).to match(/\bvehicles\b/)
        expect(queries.first).to match(/\bvehicles_car_aux\b/)
      end
    end

    describe "pluck" do
      context "aux columns are referenced" do
        let_and_capture(:queries) { Car.pluck(:fuel_type) }

        it "returns the correct result" do
          expect(queries.result).to eq(%w[gasoline hybrid electric])
        end

        it_behaves_like "queries only the aux table"
      end

      context "aux columns are chained on a where clause" do
        let_and_capture(:queries) do
          Car.where(engine_size: 1.4..1.9).pluck(:fuel_type)
        end

        it "returns the correct result" do
          expect(queries.result).to eq(%w[hybrid electric])
        end

        it_behaves_like "queries only the aux table"
        it "applies the BETWEEN clause" do
          expect(queries.first).to include("BETWEEN")
        end
      end

      context "main table columns are referenced" do
        let(:queries) do
          capture_queries { Car.where(name: "Toyota Camry").pluck(:fuel_type) }
        end

        it "returns the correct result" do
          expect(queries.result).to eq(%w[gasoline])
        end

        it_behaves_like "queries both tables"
      end

      context "main table columns are chained on a where clause" do
        let(:queries) do
          capture_queries { Car.where(name: "Toyota Camry").pluck(:fuel_type) }
        end

        it "returns the correct result" do
          expect(queries.result).to eq(%w[gasoline])
        end

        it_behaves_like "queries both tables"
      end

      context "multiple columns" do
        let(:queries) do
          capture_queries { Car.pluck(:fuel_type, :engine_size) }
        end

        it "returns the correct result" do
          expect(queries.result).to eq(
            [["gasoline", 2.0], ["hybrid", 1.5], ["electric", 1.8]]
          )
        end

        it_behaves_like "queries only the aux table"
      end

      context "multiple columns with a where clause" do
        let(:queries) do
          capture_queries do
            Car.where(name: "Toyota Camry").pluck(:fuel_type, :engine_size)
          end
        end

        it "returns the correct result" do
          expect(queries.result).to eq([["gasoline", 2.0]])
        end

        it_behaves_like "queries both tables"
      end

      context "querying the id column" do
        let_and_capture(:queries) { Car.pluck(:id) }

        it "renames the base_table_id to id" do
          expect(queries.first).to include("\"base_table_id\" AS \"id\"")
        end

        it_behaves_like "queries only the aux table"
      end
    end

    describe "maximum" do
      context "aux columns are referenced" do
        let_and_capture(:queries) { Car.maximum(:engine_size) }

        it_behaves_like "queries only the aux table"
      end

      context "aux columns are chained on a where clause" do
        let_and_capture(:queries) do
          Car.where(engine_size: 1.4..1.9).maximum(:engine_size)
        end

        it "returns the correct result" do
          expect(queries.result).to eq(1.8)
        end

        it_behaves_like "queries only the aux table"
      end

      context "main table columns are referenced" do
        let_and_capture(:queries) do
          Car.where(name: "Toyota Camry").maximum(:engine_size)
        end

        it "returns the correct result" do
          expect(queries.result).to eq(2.0)
        end

        it_behaves_like "queries both tables"
      end

      context "id column is referenced" do
        let_and_capture(:queries) { Car.maximum(:id) }

        it "renames the base_table_id to id" do
          expect(queries.first).to include('"base_table_id"')
        end

        it "has the right result" do
          expect(queries.result).to eq(3)
        end

        it_behaves_like "queries only the aux table"
      end

      context "main table columns are chained on a where clause" do
        let_and_capture(:queries) do
          Car.where(name: "Toyota Camry").maximum(:engine_size)
        end

        it "returns the correct result" do
          expect(queries.result).to eq(2.0)
        end

        it_behaves_like "queries both tables"
      end
    end
  end
end