[ruby/yarp] Move tests from test/* to test/yarp/* to match CRuby

This should make it easier on the sync to determine what changed
and hopefully result in fewer merge conflicts that have to be
manually resolved.

https://github.com/ruby/yarp/commit/17d82afbfc

test/yarp/bom_test.rb

@@ -4,7 +4,7 @@
 # test.
 return if RUBY_ENGINE == "jruby" || RUBY_ENGINE == "truffleruby"
 
-require "yarp_test_helper"
+require_relative "test_helper"
 
 class BOMTest < Test::Unit::TestCase
   def test_ident

test/yarp/comments_test.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "yarp_test_helper"
+require_relative "test_helper"
 
 class CommentsTest < Test::Unit::TestCase
   include ::YARP::DSL

test/yarp/desugar_visitor_test.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "yarp_test_helper"
+require_relative "test_helper"
 
 class DesugarVisitorTest < Test::Unit::TestCase
   def test_and_write

test/yarp/encoding_test.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "yarp_test_helper"
+require_relative "test_helper"
 
 class EncodingTest < Test::Unit::TestCase
   %w[

test/yarp/errors_test.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "yarp_test_helper"
+require_relative "test_helper"
 
 class ErrorsTest < Test::Unit::TestCase
   include ::YARP::DSL

test/yarp/heredoc_dedent_test.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "yarp_test_helper"
+require_relative "test_helper"
 
 module YARP
   class HeredocDedentTest < Test::Unit::TestCase

test/yarp/library_symbols_test.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "yarp_test_helper"
+require_relative "test_helper"
 
 if RUBY_PLATFORM =~ /linux/
   #

test/yarp/locals_test.rb

@@ -13,7 +13,7 @@ return if !defined?(RubyVM::InstructionSequence) || RUBY_VERSION < "3.2"
 # Ruby is handling large ISeqs on 32-bit machines
 return if RUBY_PLATFORM =~ /i686/
 
-require "yarp_test_helper"
+require_relative "test_helper"
 
 class LocalsTest < Test::Unit::TestCase
   invalid = []

test/yarp/location_test.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "yarp_test_helper"
+require_relative "test_helper"
 
 module YARP
   class LocationTest < Test::Unit::TestCase

test/yarp/memsize_test.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "yarp_test_helper"
+require_relative "test_helper"
 
 return if YARP::BACKEND == :FFI
 

test/yarp/newline_test.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "yarp_test_helper"
+require_relative "test_helper"
 
 return unless defined?(RubyVM::InstructionSequence)
 

test/yarp/parse_serialize_test.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "yarp_test_helper"
+require_relative "test_helper"
 
 return if YARP::BACKEND == :FFI
 

test/yarp/parse_test.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "yarp_test_helper"
+require_relative "test_helper"
 
 class ParseTest < Test::Unit::TestCase
   # When we pretty-print the trees to compare against the snapshots, we want to

test/yarp/regexp_test.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "yarp_test_helper"
+require_relative "test_helper"
 
 return if YARP::BACKEND == :FFI
 

test/yarp/ripper_compat_test.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "yarp_test_helper"
+require_relative "test_helper"
 
 module YARP
   class RipperCompatTest < Test::Unit::TestCase

test/yarp/ruby_api_test.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "yarp_test_helper"
+require_relative "test_helper"
 
 class YARPRubyAPITest < Test::Unit::TestCase
   def test_ruby_api

test/yarp/test_helper.rb

@@ -0,0 +1,100 @@
+# frozen_string_literal: true
+
+require "yarp"
+require "ripper"
+require "pp"
+require "test/unit"
+require "tempfile"
+
+puts "Using YARP backend: #{YARP::BACKEND}" if ENV["YARP_FFI_BACKEND"]
+
+module YARP
+  module Assertions
+    private
+
+    def assert_equal_nodes(expected, actual, compare_location: true, parent: nil)
+      assert_equal expected.class, actual.class
+
+      case expected
+      when Array
+        assert_equal(
+          expected.size,
+          actual.size,
+          -> { "Arrays were different sizes. Parent: #{parent.pretty_inspect}" }
+        )
+
+        expected.zip(actual).each do |(expected_element, actual_element)|
+          assert_equal_nodes(
+            expected_element,
+            actual_element,
+            compare_location: compare_location,
+            parent: actual
+          )
+        end
+      when YARP::SourceFileNode
+        deconstructed_expected = expected.deconstruct_keys(nil)
+        deconstructed_actual = actual.deconstruct_keys(nil)
+        assert_equal deconstructed_expected.keys, deconstructed_actual.keys
+
+        # Filepaths can be different if test suites were run
+        # on different machines.
+        # We accommodate for this by comparing the basenames,
+        # and not the absolute filepaths
+        assert_equal deconstructed_expected.except(:filepath), deconstructed_actual.except(:filepath)
+        assert_equal File.basename(deconstructed_expected[:filepath]), File.basename(deconstructed_actual[:filepath])
+      when YARP::Node
+        deconstructed_expected = expected.deconstruct_keys(nil)
+        deconstructed_actual = actual.deconstruct_keys(nil)
+        assert_equal deconstructed_expected.keys, deconstructed_actual.keys
+
+        deconstructed_expected.each_key do |key|
+          assert_equal_nodes(
+            deconstructed_expected[key],
+            deconstructed_actual[key],
+            compare_location: compare_location,
+            parent: actual
+          )
+        end
+      when YARP::Location
+        assert_operator actual.start_offset, :<=, actual.end_offset, -> {
+          "start_offset > end_offset for #{actual.inspect}, parent is #{parent.pretty_inspect}"
+        }
+        if compare_location
+          assert_equal(
+            expected.start_offset,
+            actual.start_offset,
+            -> { "Start locations were different. Parent: #{parent.pretty_inspect}" }
+          )
+
+          assert_equal(
+            expected.end_offset,
+            actual.end_offset,
+            -> { "End locations were different. Parent: #{parent.pretty_inspect}" }
+          )
+
+        end
+      else
+        assert_equal expected, actual
+      end
+    end
+
+    def assert_valid_locations(value, parent: nil)
+      case value
+      when Array
+        value.each do |element|
+          assert_valid_locations(element, parent: value)
+        end
+      when YARP::Node
+        value.deconstruct_keys(nil).each_value do |field|
+          assert_valid_locations(field, parent: value)
+        end
+      when YARP::Location
+        assert_operator value.start_offset, :<=, value.end_offset, -> {
+          "start_offset > end_offset for #{value.inspect}, parent is #{parent.pretty_inspect}"
+        }
+      end
+    end
+  end
+end
+
+Test::Unit::TestCase.include(YARP::Assertions)

test/yarp/unescape_test.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "yarp_test_helper"
+require_relative "test_helper"
 
 return if YARP::BACKEND == :FFI
 

test/yarp/version_test.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "yarp_test_helper"
+require_relative "test_helper"
 
 class VersionTest < Test::Unit::TestCase
   def test_version_is_set