Code for conditional builds

affected_packages_helper.rb

require 'parse_packwerk'

class AffectedPackagesHelper
  attr_reader :strict

  def initialize(modified_packs)
    @packs = modified_packs
    @memo = {}
    @all_packages ||= ParsePackwerk.all
    @strict = true
    @all_inbound_violations = generate_inbound_package_todo_hash
  end

  def dependent_packs
    @packs.each do |pack|
      inbound_dependencies_traversal(pack)
    end
    @memo.keys
  end

  def strict=(val)
    if @strict != val
      @memo = {}
      @strict = val
    end
  end

  # Returns an array of packnames of packs with `enforce_dependencies: false` as
  # a stopgap until we compute dependencies at runtime or pulled from cache.
  def packs_without_enforce_dependencies
    @all_packages.reject(&:enforces_dependencies?).map(&:name)
  end

  private

  # Creates a hash with { key: String package_name, value: Array(String) package_names
  # that are deprecation violations definined in the key's package_todo.yml
  def generate_package_todo_hash
    @all_packages.map.each_with_object({}) { |package, h|
      h[package.name] = package.violations
                                        .select(&:dependency?)
                                        .map(&:to_package_name)
                                        .uniq
    }
  end

  # Creates a hash with { key: Sring package_name, value: Array(String) package_names
  # that are inbound deprecation violations definined in the value's package_todo.yml
  def generate_inbound_package_todo_hash
    generate_package_todo_hash.each_with_object({}) do |(k, arr), h|
      arr.each do |v|
        (h[v] ||= []) << k
      end
    end
  end

  # Using BFS traversal, finds list of explicitly dependent packages defined
  # by each pack's `package.yml` and adds it to the memoized traversed packages
  # array @memo.
  #
  # @param String the name of a pack in `packs/some_pack` format
  def inbound_dependencies_traversal(package_name)
    return if @memo.key?(package_name)

    queue = [package_name]

    while !queue.empty?
      curr_package = queue.pop

      # Package does not exist or it has already been evaluated
      next if @memo.key?(curr_package) || !curr_package

      inbound_dependencies = @memo[curr_package] || @all_packages.select { |package| package.dependencies.include?(curr_package) }.map(&:name)

      # Also loop in package_todo as dependencies
      if strict
        # The root pack does not have any inbound violations
        package_todo = @all_inbound_violations[curr_package] || []
        inbound_dependencies = (inbound_dependencies + package_todo).uniq
      end

      @memo[curr_package] = inbound_dependencies

      inbound_dependencies.each do |dependency|
        if !@memo.key?(dependency)
          queue << dependency
        end
      end
    end
  end
end

affected_packages_helper_spec.rb

RSpec.describe AffectedPackagesHelper do
  describe '#dependent_packs' do
    subject do
      helper = described_class.new(['packs/bar'])
      helper.strict = strict
      helper
    end

    let(:strict) { false }

    let(:package_foo) do
      ParsePackwerk::Package.new(
        name: 'packs/foo',
        enforce_privacy: true,
        enforce_dependencies: true,
        dependencies: ['packs/bar'],
        metadata: {},
        config: {}
      )
    end

    let(:package_bar) do
      ParsePackwerk::Package.new(
        name: 'packs/bar',
        enforce_privacy: true,
        enforce_dependencies: true,
        dependencies: [],
        metadata: {},
        config: {}
      )
    end

    let(:package_baz) do
      ParsePackwerk::Package.new(
        name: 'packs/baz',
        enforce_privacy: true,
        enforce_dependencies: true,
        dependencies: [],
        metadata: {},
        config: {}
      )
    end

    let(:package_qux) do
      ParsePackwerk::Package.new(
        name: 'packs/qux',
        enforce_privacy: true,
        enforce_dependencies: false,
        dependencies: [],
        metadata: {},
        config: {}
      )
    end

    let(:dependency_violation) do
      ParsePackwerk::Violation.new(
        class_name: 'FakeClass',
        files: ['packs/bar/fake_class.rb'],
        to_package_name: 'packs/bar',
        type: 'dependency'
      )
    end

    let(:privacy_violation) do
      ParsePackwerk::Violation.new(
        class_name: 'FakeClass',
        files: ['packs/bar/fake_class.rb'],
        to_package_name: 'packs/bar',
        type: 'privacy'
      )
    end

    let(:all_packages) { [package_foo, package_bar, package_baz, package_qux] }

    before do
      allow(ParsePackwerk).to receive(:all).and_return(all_packages)
    end

    context 'when strict is true' do
      let(:strict) { true }

      context 'when there are no violations' do
        it 'returns the affected packages' do
          expect(subject.dependent_packs).to match_array(['packs/bar', 'packs/foo'])
        end
      end

      context 'when there are violations' do
        before do
          allow(package_baz).to receive(:violations).and_return([dependency_violation, privacy_violation])
        end

        it 'returns packs that are deprecated dependency violations' do
          expect(subject.dependent_packs).to match_array(['packs/bar', 'packs/foo', 'packs/baz'])
        end

        it 'returns unique set of packs' do
          allow(package_baz).to receive(:violations).and_return([dependency_violation, dependency_violation])
          expect(subject.dependent_packs).to match_array(['packs/bar', 'packs/foo', 'packs/baz'])
        end
      end
    end

    context 'when strict is false' do
      let(:strict) { false }

      context 'when there are no violations' do
        it 'returns the affected packages' do
          expect(subject.dependent_packs).to match_array(['packs/bar', 'packs/foo'])
        end
      end

      context 'when there are violations' do
        it 'returns packs without the deprecated dependency violations' do
          allow(package_baz).to receive(:violations).and_return([dependency_violation])
          expect(subject.dependent_packs).to match_array(['packs/bar', 'packs/foo'])
        end
      end
    end

    context 'packs_without_enforce_dependencies' do
      it 'returns the names of the packs without `enforce_dependencies: true`' do
        expect(subject.packs_without_enforce_dependencies).to match_array(['packs/qux'])
      end
    end
  end
end

LICENSE

MIT License

Copyright (c) 2022 Gusto

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