1 files changed, 171 insertions, 0 deletions
diff --git a/test/rubygems/test_gem_ext_cargo_builder.rb b/test/rubygems/test_gem_ext_cargo_builder.rb
new file mode 100644
index 0000000000..5faf3e2480
--- /dev/null
+++ b/test/rubygems/test_gem_ext_cargo_builder.rb
@@ -0,0 +1,171 @@
+# frozen_string_literal: true
+
+require_relative "helper"
+require "rubygems/ext"
+require "open3"
+
+class TestGemExtCargoBuilder < Gem::TestCase
+  def setup
+    super
+
+    @rust_envs = {
+      "CARGO_HOME" => ENV.fetch("CARGO_HOME", File.join(@orig_env["HOME"], ".cargo")),
+      "RUSTUP_HOME" => ENV.fetch("RUSTUP_HOME", File.join(@orig_env["HOME"], ".rustup")),
+    }
+  end
+
+  def setup_rust_gem(name)
+    @ext = File.join(@tempdir, "ext")
+    @dest_path = File.join(@tempdir, "prefix")
+    @fixture_dir = Pathname.new(File.expand_path("test_gem_ext_cargo_builder/#{name}/", __dir__))
+
+    FileUtils.mkdir_p @dest_path
+    FileUtils.cp_r(@fixture_dir.to_s, @ext)
+  end
+
+  def test_build_cdylib
+    skip_unsupported_platforms!
+    setup_rust_gem "rust_ruby_example"
+
+    output = []
+
+    Dir.chdir @ext do
+      ENV.update(@rust_envs)
+      builder = Gem::Ext::CargoBuilder.new
+      builder.build "Cargo.toml", @dest_path, output
+    end
+
+    output = output.join "\n"
+    bundle = File.join(@dest_path, "rust_ruby_example.#{RbConfig::CONFIG["DLEXT"]}")
+
+    assert_match(/Finished/, output)
+    assert_match(/release/, output)
+    assert_ffi_handle bundle, "Init_rust_ruby_example"
+  rescue StandardError => e
+    pp output if output
+
+    raise(e)
+  end
+
+  def test_rubygems_cfg_passed_to_rustc
+    skip_unsupported_platforms!
+    setup_rust_gem "rust_ruby_example"
+    version_slug = Gem::VERSION.tr(".", "_")
+    output = []
+
+    replace_in_rust_file("src/lib.rs", "rubygems_x_x_x", "rubygems_#{version_slug}")
+
+    Dir.chdir @ext do
+      ENV.update(@rust_envs)
+      builder = Gem::Ext::CargoBuilder.new
+      builder.build "Cargo.toml", @dest_path, output
+    end
+
+    output = output.join "\n"
+    bundle = File.join(@dest_path, "rust_ruby_example.#{RbConfig::CONFIG["DLEXT"]}")
+
+    assert_ffi_handle bundle, "hello_from_rubygems"
+    assert_ffi_handle bundle, "hello_from_rubygems_version"
+    refute_ffi_handle bundle, "should_never_exist"
+  rescue StandardError => e
+    pp output if output
+
+    raise(e)
+  end
+
+  def test_build_fail
+    skip_unsupported_platforms!
+    setup_rust_gem "rust_ruby_example"
+
+    FileUtils.rm(File.join(@ext, "src/lib.rs"))
+
+    error = assert_raise(Gem::InstallError) do
+      Dir.chdir @ext do
+        ENV.update(@rust_envs)
+        builder = Gem::Ext::CargoBuilder.new
+        builder.build "Cargo.toml", @dest_path, []
+      end
+    end
+
+    assert_match(/cargo\s.*\sfailed/, error.message)
+  end
+
+  def test_full_integration
+    skip_unsupported_platforms!
+    setup_rust_gem "rust_ruby_example"
+
+    require "open3"
+
+    Dir.chdir @ext do
+      require "tmpdir"
+
+      env_for_subprocess = @rust_envs.merge("GEM_HOME" => Gem.paths.home)
+      gem = [env_for_subprocess, *ruby_with_rubygems_in_load_path, File.expand_path("../../exe/gem", __dir__)]
+
+      Dir.mktmpdir("rust_ruby_example") do |dir|
+        built_gem = File.expand_path(File.join(dir, "rust_ruby_example.gem"))
+        Open3.capture2e(*gem, "build", "rust_ruby_example.gemspec", "--output", built_gem)
+        Open3.capture2e(*gem, "install", "--verbose", "--local", built_gem, *ARGV)
+
+        stdout_and_stderr_str, status = Open3.capture2e(env_for_subprocess, *ruby_with_rubygems_in_load_path, "-rrust_ruby_example", "-e", "puts 'Result: ' + RustRubyExample.reverse('hello world')")
+        assert status.success?, stdout_and_stderr_str
+        assert_match "Result: #{"hello world".reverse}", stdout_and_stderr_str
+      end
+    end
+  end
+
+  def test_custom_name
+    skip_unsupported_platforms!
+    setup_rust_gem "custom_name"
+
+    Dir.chdir @ext do
+      require "tmpdir"
+
+      env_for_subprocess = @rust_envs.merge("GEM_HOME" => Gem.paths.home)
+      gem = [env_for_subprocess, *ruby_with_rubygems_in_load_path, File.expand_path("../../exe/gem", __dir__)]
+
+      Dir.mktmpdir("custom_name") do |dir|
+        built_gem = File.expand_path(File.join(dir, "custom_name.gem"))
+        Open3.capture2e(*gem, "build", "custom_name.gemspec", "--output", built_gem)
+        Open3.capture2e(*gem, "install", "--verbose", "--local", built_gem, *ARGV)
+      end
+
+      stdout_and_stderr_str, status = Open3.capture2e(env_for_subprocess, *ruby_with_rubygems_in_load_path, "-rcustom_name", "-e", "puts 'Result: ' + CustomName.say_hello")
+
+      assert status.success?, stdout_and_stderr_str
+      assert_match "Result: Hello world!", stdout_and_stderr_str
+    end
+  end
+
+  private
+
+  def skip_unsupported_platforms!
+    pend "jruby not supported" if Gem.java_platform?
+    pend "truffleruby not supported (yet)" if RUBY_ENGINE == "truffleruby"
+    system(@rust_envs, "cargo", "-V", out: IO::NULL, err: [:child, :out])
+    pend "cargo not present" unless $?.success?
+    pend "ruby.h is not provided by ruby repo" if ruby_repo?
+    pend "rust toolchain of mingw is broken" if mingw_windows?
+  end
+
+  def assert_ffi_handle(bundle, name)
+    require "fiddle"
+    dylib_handle = Fiddle.dlopen bundle
+    assert_nothing_raised { dylib_handle[name] }
+  ensure
+    dylib_handle&.close
+  end
+
+  def refute_ffi_handle(bundle, name)
+    require "fiddle"
+    dylib_handle = Fiddle.dlopen bundle
+    assert_raise { dylib_handle[name] }
+  ensure
+    dylib_handle&.close
+  end
+
+  def replace_in_rust_file(name, from, to)
+    content = @fixture_dir.join(name).read.gsub(from, to)
+    File.write(File.join(@ext, name), content)
+  end
+end