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Testing Sequence Reset Implementation in Factory Bot

This test suite validates the sequence resetting functionality in FactoryBot, focusing on the rewind_sequences method. It ensures proper handling of both global and local sequences for generating test data, particularly for email addresses and names across different factory definitions.

Test Coverage Overview

The test suite comprehensively covers sequence resetting functionality in FactoryBot.

Key areas tested include:

Basic sequence resetting for global sequences
Inline sequence handling within factories
Collision prevention between global and local sequences
Factory-prefixed sequence behavior
Sequence handling within identical traits across different factories

Implementation Analysis

The testing approach uses RSpec’s describe/it blocks to organize test scenarios systematically. The implementation leverages FactoryBot’s sequence definition syntax and combines it with dynamic class creation for thorough testing.

Notable patterns include:

Dynamic test class definition using define_class
Factory definition with both global and local sequences
Usage of build_list for multiple object creation
Trait-based sequence definition testing

Technical Details

Testing tools and configuration:

RSpec as the testing framework
FactoryBot’s Syntax::Methods inclusion
Dynamic class creation helpers
Sequence definition with both simple and enumerable values
Factory trait definitions
Multiple assertion patterns for sequence verification

Best Practices Demonstrated

The test suite exemplifies high-quality testing practices through organized and comprehensive test coverage.

Notable practices include:

Isolated test cases for different sequence scenarios
Clear test case naming and organization
Comprehensive edge case coverage
Proper setup and teardown of test data
Effective use of factory patterns and traits

thoughtbot/factory_bot

spec/acceptance/sequence_resetting_spec.rb

            
describe "FactoryBot.rewind_sequences" do
  include FactoryBot::Syntax::Methods

  it "resets all sequences back to their starting values" do
    FactoryBot.define do
      sequence(:email) { |n| "somebody#{n}@example.com" }
      sequence(:name, %w[Joe Josh].to_enum)
    end

    2.times do
      generate(:email)
      generate(:name)
    end

    FactoryBot.rewind_sequences

    email = generate(:email)
    name = generate(:name)

    expect(email).to eq "[email protected]"
    expect(name).to eq "Joe"
  end

  it "resets inline sequences back to their starting value" do
    define_class("User") { attr_accessor :email }

    FactoryBot.define do
      factory :user do
        sequence(:email) { |n| "somebody#{n}@example.com" }
      end
    end

    build_list(:user, 2)

    FactoryBot.rewind_sequences

    user = build(:user)

    expect(user.email).to eq "[email protected]"
  end

  it "does not collide with globally registered factories" do
    define_class("User") { attr_accessor :email }

    FactoryBot.define do
      sequence(:email) { |n| "global-somebody#{n}@example.com" }

      factory :user do
        sequence(:email) { |n| "local-somebody#{n}@example.com" }
      end
    end

    2.times do
      generate(:email)
    end

    build_list(:user, 2)

    FactoryBot.rewind_sequences

    user = build(:user)
    email = generate(:email)

    expect(user.email).to eq "[email protected]"
    expect(email).to eq "[email protected]"
  end

  it "still allows global sequences prefixed with a factory name" do
    define_class("User") { attr_accessor :email }

    FactoryBot.define do
      sequence(:user_email) { |n| "global-somebody#{n}@example.com" }

      factory :user do
        sequence(:email) { |n| "local-somebody#{n}@example.com" }
      end
    end

    2.times do
      generate(:user_email)
    end

    build_list(:user, 2)

    FactoryBot.rewind_sequences

    user = build(:user)
    email = generate(:user_email)

    expect(user.email).to eq "[email protected]"
    expect(email).to eq "[email protected]"
  end

  it "allows setting sequences within identically named traits" do
    define_class("User") { attr_accessor :email }
    define_class("Person") { attr_accessor :email }

    FactoryBot.define do
      factory :user do
        trait :with_email do
          sequence(:email) { |n| "user#{n}@example.com" }
        end
      end

      factory :person do
        trait :with_email do
          sequence(:email) { |n| "person#{n}@example.com" }
        end
      end
    end

    build_list(:user, 2, :with_email)
    build_list(:person, 2, :with_email)

    FactoryBot.rewind_sequences

    user = build(:user, :with_email)
    person = build(:person, :with_email)

    expect(user.email).to eq "[email protected]"
    expect(person.email).to eq "[email protected]"
  end
end