Test RPM dependency generators for rubygems.

Add tests for RPM dependency generators that execute during build.
The tests make use of methods available in tools present in the
upstream ruby tar archive to find and set up the ruby executable.
This is then used to execute the dependency generator script with
a given test input passed into the subprocess and collect the output
given out by the generator for testing.

Skip "test_generator_on_gem_with_multiple_conflict_constraints" for
now. rubygems.req is currently only capable of filtering out a single
conflict requirement that is specified on a given dependency.

Execute it in the %check section before the long-running
Ruby test suite starts. If testing the generators fails it means there
is the possibility of generating bogus requires,
which is a valuable information to get sooner rather than later.

rpm_test_helper.rb

@@ -0,0 +1,166 @@
+require 'tmpdir'
+require 'tempfile'
+require 'fileutils'
+# Available in Ruby upstream sources under tool/lib/envutil.rb
+# Required for finding and setting up the built ruby binary.
+require 'envutil'
+
+module RPMTestHelper
+  def setup
+    @tmpdir = Dir.mktmpdir
+    @tempfiles = []
+  end
+
+  def teardown
+    @tempfiles.each do |file|
+      file.close
+      file.unlink
+    end
+
+    FileUtils.rmtree(@tmpdir)
+  end
+
+  GENERATOR_SCRIPT = ENV['GENERATOR_SCRIPT'].clone.freeze
+  if GENERATOR_SCRIPT.nil? || GENERATOR_SCRIPT == ''
+    raise "GENERATOR_SCRIPT is not specified." \
+      "Specify the ENV variable with absolute path to the generator."
+  end
+
+  Dependency = Struct.new('Dependency', :name, :requirements) do
+    def to_rpm_str
+      "rubygem(#{self.name})"
+    end
+  end
+
+  def make_gemspec(gem_info)
+    file = Tempfile.new('req_gemspec', @tmpdir)
+    # Fake gemspec with enough to pass most checks
+    # Rubygems uses to validate the format.
+    gemspec_contents = <<~EOF
+      # -*- encoding: utf-8 -*-
+      # stub: #{gem_info.name} #{gem_info.version} ruby lib
+
+      Gem::Specification.new do |s|
+        s.name = "#{gem_info.name}".freeze
+        s.version = "#{gem_info.version}"
+
+        s.required_rubygems_version = Gem::Requirement.new(">= 0".freeze) if s.respond_to? :required_rubygems_version=
+        s.require_paths = ["lib".freeze]
+        s.authors = ["John Doe".freeze]
+        s.bindir = "bin".freeze
+        s.date = "2023-12-15"
+        s.description = "Fake gemspec helper for testing Rubygem Generators".freeze
+        s.email = ["example@example.com".freeze]
+        s.files = ["LICENSE.txt".freeze, "lib/#{gem_info.name}.rb".freeze, "#{gem_info.name}.gemspec".freeze]
+        s.homepage = "https://pkgs.fedoraproject.org/rpms/ruby".freeze
+        s.licenses = ["MIT".freeze]
+        s.required_ruby_version = Gem::Requirement.new(">= 2.5.0".freeze)
+        s.rubygems_version = "3.3.5".freeze
+        s.summary = "Fake gemspec for testing Rubygem Generators".freeze
+
+        if s.respond_to? :specification_version then
+          s.specification_version = 4
+        end
+
+        if s.respond_to? :add_runtime_dependency then
+          #{gem_info.gemspec_runtime_dep_str}
+        else
+          #{gem_info.gemspec_dep_str}
+        end
+      end
+    EOF
+
+    file.write gemspec_contents
+    file.rewind
+    @tempfiles << file
+    file
+  end
+
+  # Caller is expected to close subprocess stdin via #close_write
+  # in order to let subprocess proceed if the process is reading
+  # from STDIN in a loop.
+  def rb_subprocess(*args)
+    args = [GENERATOR_SCRIPT] if args.empty?
+    ruby = EnvUtil.rubybin
+    f = IO.popen([ruby] + args, 'r+') #, external_encoding: external_encoding)
+    yield(f)
+  ensure
+    f.close unless !f || f.closed?
+  end
+
+  def run_generator_single_file(gem_info)
+    lines = []
+    gemspec_f = make_gemspec(gem_info)
+
+    rb_subprocess do |io|
+      io.write gemspec_f.path
+      io.close_write
+      lines = io.readlines
+    end
+
+    lines
+  end
+
+  def helper_rubygems_dependency
+    "ruby(rubygems)"
+  end
+
+  class GemInfo
+    attr_accessor :name, :version, :dependencies
+
+    def initialize(name: 'foo', version: '1.2.3', dependencies: [])
+      @name = name
+      @version = version
+      @dependencies = dependencies
+    end
+
+    def dependencies=(other)
+      raise ArgumentError, "#{self.class.name}##{__method__.to_s}: Expected array of `Dependency' elements" \
+        unless other.is_a?(Array) && other.all? { |elem| elem.respond_to?(:name) && elem.respond_to?(:requirements) }
+
+      @dependencies = other
+    end
+
+    def to_rpm_str
+      "rubygem(#{self.name})"
+    end
+
+    def gemspec_dep_str
+      return '' if self.dependencies.nil? || self.dependencies.empty?
+      @dependencies.inject("") do |memo, dep|
+        memo += if dep.requirements && !dep.requirements.empty?
+                  %Q|s.add_dependency(%q<#{dep.name}>.freeze, #{handle_dep_requirements(dep.requirements)})|
+                else
+                  %Q|s.add_dependency(%q<#{dep.name}>.freeze)|
+                end
+
+        memo += "\n"
+      end
+    end
+
+    def gemspec_runtime_dep_str
+      return '' if self.dependencies.nil? || self.dependencies.empty?
+
+      @dependencies.inject("") do |memo, dep|
+        memo += if dep.requirements && !dep.requirements.empty?
+                  %Q|s.add_runtime_dependency(%q<#{dep.name}>.freeze, #{handle_dep_requirements(dep.requirements)})|
+                else
+                  %Q|s.add_runtime_dependency(%q<#{dep.name}>.freeze)|
+                end
+
+        memo += "\n"
+      end
+    end
+
+    private
+
+    def handle_dep_requirements(reqs)
+      raise ArgumentError, "#{self.class.name}##{__method__.to_s}: Reqs must be an array." \
+        unless reqs.is_a? Array
+      raise ArgumentError, "#{self.class.name}##{__method__.to_s}: Reqs must not be empty for this method." \
+        if reqs.empty?
+
+      '[ "' + reqs.join('", "') + '" ]'
+    end
+  end
+end

ruby.spec

@@ -230,6 +230,11 @@ Source13: test_abrt.rb
 Source14: test_systemtap.rb
 # Ruby OpenSSL FIPS tests.
 Source15: test_openssl_fips.rb
+# RPM gem Requires dependency generator tests.
+Source16: rpm_test_helper.rb
+Source17: test_rubygems_req.rb
+Source18: test_rubygems_prov.rb
+Source19: test_rubygems_con.rb
 
 # The load directive is supported since RPM 4.12, i.e. F21+. The build process
 # fails on older Fedoras.
@@ -1134,6 +1139,21 @@ ln -sfr probes.d %{_vpath_builddir}/
 make -C %{_vpath_builddir} runruby TESTRUN_SCRIPT=%{SOURCE14}
 %endif
 
+# Test dependency generators for RPM
+GENERATOR_SCRIPT="%{SOURCE9}" \
+make -C %{_vpath_builddir} runruby TESTRUN_SCRIPT=" \
+  -I%{_builddir}/%{buildsubdir}/tool/lib -I%{_sourcedir} --enable-gems \
+  %{SOURCE17} --verbose"
+GENERATOR_SCRIPT="%{SOURCE10}" \
+make -C %{_vpath_builddir} runruby TESTRUN_SCRIPT=" \
+  -I%{_builddir}/%{buildsubdir}/tool/lib -I%{_sourcedir} --enable-gems \
+  %{SOURCE18} --verbose"
+GENERATOR_SCRIPT="%{SOURCE11}" \
+make -C %{_vpath_builddir} runruby TESTRUN_SCRIPT=" \
+  -I%{_builddir}/%{buildsubdir}/tool/lib -I%{_sourcedir} --enable-gems \
+  %{SOURCE19} --verbose"
+
+
 DISABLE_TESTS=""
 MSPECOPTS=""
 

test_rubygems_con.rb

@@ -0,0 +1,124 @@
+# frozen_string_literal: true
+
+require 'test/unit'
+require 'rpm_test_helper'
+
+class TestRubyGemsCon < Test::Unit::TestCase
+  include RPMTestHelper
+
+  def test_filter_out_regular_requirements
+    gem_i = GemInfo.new
+
+    lines = run_generator_single_file(gem_i)
+
+    assert_equal(0, lines.size)
+
+    deps = [ Dependency.new('bar') ]
+    gem_i.dependencies = deps
+
+    lines = run_generator_single_file(gem_i)
+
+    assert_equal(0, lines.size)
+
+    deps = [
+      Dependency.new('bar'),
+      Dependency.new('baq'),
+      Dependency.new('quz')
+    ]
+
+    gem_i.dependencies = deps
+    lines = run_generator_single_file(gem_i)
+
+    assert_equal(0, lines.size)
+
+    deps = [
+      Dependency.new('bar', ['>= 4.1']),
+      Dependency.new('baz', ['~> 3.2']),
+      Dependency.new('quz', ['>= 5.6'])
+    ]
+
+    gem_i.dependencies = deps
+
+    lines = run_generator_single_file(gem_i)
+
+    assert_equal(0, lines.size)
+  end
+
+  def test_single_gem_single_version_conflict
+    con = Dependency.new('bar', ['!= 0.4.4'])
+
+    gem_i = GemInfo.new(dependencies: [ con ])
+    lines = run_generator_single_file(gem_i)
+
+    assert_equal(1, lines.size)
+    assert_equal("#{con.to_rpm_str} = 0.4.4\n", lines.first)
+  end
+
+  def test_multiple_gems_with_single_conflict
+    cons = [
+      Dependency.new('bar', ['!= 1.1']),
+      Dependency.new('baq', ['!= 1.2.2']),
+      Dependency.new('quz', ['!= 1.3'])
+    ]
+
+    gem_i = GemInfo.new(dependencies: cons)
+
+    lines = run_generator_single_file(gem_i)
+
+    assert_equal(3, lines.size)
+
+    assert_equal("#{cons[0].to_rpm_str} = 1.1\n"  , lines[0])
+    assert_equal("#{cons[1].to_rpm_str} = 1.2.2\n", lines[1])
+    assert_equal("#{cons[2].to_rpm_str} = 1.3\n"  , lines[2])
+  end
+
+  def test_multiple_conflicts_on_single_gem
+    con = Dependency.new('bar', ['!= 2.3', '!= 2.4'])
+
+    gem_i = GemInfo.new(dependencies: [con])
+
+    lines = run_generator_single_file(gem_i)
+
+    assert_equal(1, lines.size)
+    rpm_name = con.to_rpm_str
+    left_rpm_constraint = "(#{rpm_name} = 2.3 with "
+    right_rpm_constraint = "#{rpm_name} = 2.4)\n"
+    assert_equal((left_rpm_constraint + right_rpm_constraint), lines[0])
+
+    con = Dependency.new('bar', ['!= 2.3', '!= 2.4', '!= 4.5'])
+
+    gem_i = GemInfo.new(dependencies: [ con ])
+
+    lines = run_generator_single_file(gem_i)
+
+    assert_equal(1, lines.size)
+
+    rpm_name = con.to_rpm_str
+    left_rpm_constraint = "(#{rpm_name} = 2.3 with "
+    middle_rpm_constraint = "#{rpm_name} = 2.4 with "
+    right_rpm_constraint = "#{rpm_name} = 4.5)\n"
+
+    assert_equal((left_rpm_constraint + middle_rpm_constraint + right_rpm_constraint), lines[0])
+  end
+
+  def test_generates_conflicts_while_ignoring_regular_requirements
+    deps = [
+      Dependency.new('bar', ['>= 2.3', '!= 2.4.2']),
+      Dependency.new('quz', ['~> 3.0', '!= 3.2'])
+    ]
+
+    gem_i = GemInfo.new(dependencies: deps)
+
+    lines = run_generator_single_file(gem_i)
+
+    assert_equal(2, lines.size)
+
+    rpm_name = deps[0].to_rpm_str
+    rpm_constraint = "#{rpm_name} = 2.4.2\n"
+    assert_equal(rpm_constraint, lines[0])
+
+    rpm_name = deps[1].to_rpm_str
+    rpm_constraint = "#{rpm_name} = 3.2\n"
+    assert_equal(rpm_constraint, lines[1])
+  end
+end

test_rubygems_prov.rb

@@ -0,0 +1,52 @@
+# frozen_string_literal: true
+
+require 'test/unit'
+require 'rpm_test_helper'
+
+class TestRubyGemsProv < Test::Unit::TestCase
+  include RPMTestHelper
+
+  def test_provides_the_gem_version
+    gem_i = GemInfo.new(version: '1.2')
+
+    lines = run_generator_single_file(gem_i)
+
+    assert_equal(1, lines.size)
+    assert_equal("#{gem_i.to_rpm_str} = #{gem_i.version}\n", lines.first)
+
+    gem_i = GemInfo.new(name: 'somegem_foo', version: '4.5.6')
+
+    lines = run_generator_single_file(gem_i)
+
+    assert_equal(1, lines.size)
+    assert_equal("#{gem_i.to_rpm_str} = #{gem_i.version}\n", lines.first)
+
+    deps = [
+      Dependency.new('bar'),
+      Dependency.new('baq', [">= 1.2"]),
+      Dependency.new('quz', ["!= 3.2"])
+    ]
+    gem_i = GemInfo.new(dependencies: deps)
+
+    lines = run_generator_single_file(gem_i)
+
+    assert_equal(1, lines.size)
+    assert_equal("#{gem_i.to_rpm_str} = #{gem_i.version}\n", lines.first)
+  end
+
+  def test_translates_prelease_version_provides_from_rubygems_to_rpm
+    gem_i = GemInfo.new(version: '1.2.3.dev')
+
+    lines = run_generator_single_file(gem_i)
+
+    assert_equal(1, lines.size)
+    assert_equal("#{gem_i.to_rpm_str} = 1.2.3~dev\n", lines.first)
+
+    gem_i = GemInfo.new(name: 'foo2', version: '1.2.3.dev.2')
+
+    lines = run_generator_single_file(gem_i)
+
+    assert_equal(1, lines.size)
+    assert_equal("#{gem_i.to_rpm_str} = 1.2.3~dev.2\n", lines.first)
+  end
+end

test_rubygems_req.rb

@@ -0,0 +1,205 @@
+# frozen_string_literal: true
+
+require 'test/unit'
+require 'rpm_test_helper'
+
+class TestRubyGemsReq < Test::Unit::TestCase
+  include RPMTestHelper
+
+  def test_depends_on_rubygems
+    gem_i = GemInfo.new
+
+    lines = run_generator_single_file(gem_i)
+
+    assert_equal(1, lines.size)
+    assert_equal("#{helper_rubygems_dependency}\n", lines.first)
+  end
+
+  def test_requires_rubygems_and_dependency
+    dep = Dependency.new('bar')
+    gem_i = GemInfo.new(dependencies: [dep])
+
+    lines = run_generator_single_file(gem_i)
+
+    assert_equal(2, lines.size)
+    assert_equal("#{helper_rubygems_dependency}\n", lines.first)
+    assert_equal("#{dep.to_rpm_str}\n", lines[1])
+  end
+
+  def test_requires_multiple_dependencies_with_constraint
+    constraints = [
+      '>= 3.0',
+      '>= 3.0.0',
+      '>= 3',
+      '= 1.0.2',
+      '= 3.0',
+      '< 3.2',
+      '<= 3.4'
+    ]
+
+    dependencies = []
+    constraints.each_with_index do |constraint, idx|
+      dependencies << Dependency.new("bar#{idx}", [constraint])
+    end
+
+    gem_i = GemInfo.new(dependencies: dependencies)
+
+    lines = run_generator_single_file(gem_i)
+    # + 1 for the rubygems dependency
+    assert_equal(constraints.size + 1, lines.size)
+    dependencies.each_with_index do |dep, idx|
+      rpm_dep_name = dep.to_rpm_str
+      # Start indexing lines at 1, to jump over rubygems dependency
+      assert_equal("#{rpm_dep_name} #{constraints[idx]}\n", lines[idx + 1])
+    end
+  end
+
+  def test_expands_pessimistic_constraint_for_rpm
+    dep = Dependency.new('bar', ['~> 1.2'])
+
+    gem_i = GemInfo.new(dependencies: [dep])
+
+    lines = run_generator_single_file(gem_i)
+
+    assert_equal(2, lines.size)
+
+    rpm_dep_name = dep.to_rpm_str
+    left_constraint = "#{rpm_dep_name} >= 1.2"
+    right_constraint = "#{rpm_dep_name} < 2"
+    expected_constraint = "(#{left_constraint} with #{right_constraint})\n"
+    assert_equal(expected_constraint, lines[1])
+  end
+
+  def test_multiple_pessimistically_constrained_dependencies
+    dependencies = []
+    dep_map = [
+      {
+        constraint:     '~> 1.2.3',
+        expanded_left:  '>= 1.2.3',
+        expanded_rigth: '< 1.3',
+        gem_name: 'bar1'
+      },
+      {
+        constraint:     '~> 1.2',
+        expanded_left:  '>= 1.2',
+        expanded_rigth: '< 2',
+        gem_name: 'bar2'
+      },
+      {
+        constraint:     '~> 3',
+        expanded_left:  '>= 3',
+        expanded_rigth: '< 4',
+        gem_name: 'bar3'
+      }
+    ].each do |deps|
+      dependencies << Dependency.new(deps[:gem_name], [deps[:constraint]])
+    end
+
+    gem_i = GemInfo.new(dependencies: dependencies)
+
+    lines = run_generator_single_file(gem_i)
+
+    assert_equal(dep_map.size + 1, lines.size)
+
+    dep_map.each_with_index do |hash, idx|
+      rpm_dep_name = dependencies[idx].to_rpm_str
+      left_constraint = rpm_dep_name + ' ' + hash[:expanded_left]
+      right_constraint = rpm_dep_name + ' ' + hash[:expanded_rigth]
+      expected_constraint = "(#{left_constraint} with #{right_constraint})\n"
+      assert_equal(expected_constraint, lines[idx + 1])
+    end
+  end
+
+  def test_multiple_constraints_on_one_dependency_composes_constraints_for_RPM
+    # The quoting here depends on how the constraint is expanded in the helpers.
+    # right now the form is `["#{constraint}"]`, therefore we have to not specify
+    # left and right quotes.
+    constraints = ['>= 0.2.3', '<= 0.2.5']
+    dep = Dependency.new('baz', constraints)
+
+    gem_i = GemInfo.new(dependencies: [dep])
+
+    lines = run_generator_single_file(gem_i)
+
+    assert_equal(2, lines.size)
+    rpm_dep_name = dep.to_rpm_str
+    assert_equal("(#{rpm_dep_name} >= 0.2.3 with #{rpm_dep_name} <= 0.2.5)\n", lines[1])
+
+    # Not sure who would compose a dependency like this, but it's possible
+    # to do with the current generator
+    constraints = ['> 0.4.5', '< 0.6.4', '>= 2.3', '<= 2.5.3']
+    dep = Dependency.new('qux', constraints)
+
+    gem_i = GemInfo.new(dependencies: [dep])
+
+    lines = run_generator_single_file(gem_i)
+
+    rpm_dep = dep.to_rpm_str
+    expected_str = "(#{rpm_dep} > 0.4.5 with #{rpm_dep} < 0.6.4 with " \
+                   "#{rpm_dep} >= 2.3 with #{rpm_dep} <= 2.5.3)\n"
+
+    assert_equal(2, lines.size)
+    assert_equal(expected_str, lines[1])
+  end
+
+  # https://bugzilla.redhat.com/show_bug.cgi?id=1561487
+  def test_depends_on_gem_with_version_conflict
+    dep = Dependency.new('baz', ['!= 0.4'])
+
+    gem_i = GemInfo.new(dependencies: [dep])
+
+    lines = run_generator_single_file(gem_i)
+
+    assert_equal(2, lines.size)
+    assert_equal("#{dep.to_rpm_str}\n", lines[1])
+  end
+
+  def test_filters_conflict_from_regular_version_constraints
+    constraint = ['> 1.2.4', '!= 1.2.7']
+    dep = Dependency.new('baq', constraint)
+
+    gem_i = GemInfo.new(dependencies: [dep])
+
+    lines = run_generator_single_file(gem_i)
+
+    assert_equal(2, lines.size)
+    assert_equal("#{dep.to_rpm_str} > 1.2.4\n", lines[1])
+  end
+
+  def test_filtering_conflicts_is_not_depending_on_contraint_ordering
+    constraints = ['!= 1.2.7', '> 1.2.4']
+    dep = Dependency.new('baq', constraints)
+
+    gem_i = GemInfo.new(dependencies: [dep])
+
+    lines = run_generator_single_file(gem_i)
+
+    assert_equal(2, lines.size)
+    assert_equal("#{dep.to_rpm_str} > 1.2.4\n", lines[1])
+  end
+
+  def test_filters_multiple_conflicts_from_dependency
+    omit "Case not yet supported."
+    constraints = ['!= 1.2.4', '!= 1.2.5', '!= 2.3', '!= 4.8']
+    dep = Dependency.new('baf', constraints)
+
+    gem_i = GemInfo.new(dependencies: [dep])
+
+    lines = run_generator_single_file(gem_i)
+
+    assert_equal(2, lines.size)
+    assert_equal("#{dep.to_rpm_str}\n", lines[1])
+  end
+
+  def test_filters_multiple_conflicts_from_dependency_but_keeps_regular_constraint
+    constraints = ['!= 1.2.4', '!= 1.2.5', '!= 2.3', '<= 4.8']
+    dep = Dependency.new('bam', constraints)
+
+    gem_i = GemInfo.new(dependencies: [dep])
+
+    lines = run_generator_single_file(gem_i)
+
+    assert_equal(2, lines.size)
+    assert_equal("#{dep.to_rpm_str} <= 4.8\n", lines[1])
+  end
+end