[ruby/prism] ruby_parser translator

https://github.com/ruby/prism/commit/1925b970c7

lib/prism/prism.gemspec

@@ -36,6 +36,7 @@ Gem::Specification.new do |spec|
     "docs/releasing.md",
     "docs/ripper.md",
     "docs/ruby_api.md",
+    "docs/ruby_parser_translation.md",
     "docs/serialization.md",
     "docs/testing.md",
     "ext/prism/api_node.c",
@@ -90,6 +91,7 @@ Gem::Specification.new do |spec|
     "lib/prism/translation/parser/lexer.rb",
     "lib/prism/translation/parser/rubocop.rb",
     "lib/prism/translation/ripper.rb",
+    "lib/prism/translation/ruby_parser.rb",
     "lib/prism/visitor.rb",
     "src/diagnostic.c",
     "src/encoding.c",

lib/prism/translation.rb

@@ -2,11 +2,10 @@
 
 module Prism
   # This module is responsible for converting the prism syntax tree into other
-  # syntax trees. At the moment it only supports converting to the
+  # syntax trees.
-  # whitequark/parser gem's syntax tree, but support is planned for the
-  # seattlerb/ruby_parser gem's syntax tree as well.
   module Translation
     autoload :Parser, "prism/translation/parser"
     autoload :Ripper, "prism/translation/ripper"
+    autoload :RubyParser, "prism/translation/ruby_parser"
   end
 end

test/prism/ruby_parser_test.rb

@@ -0,0 +1,149 @@
+# frozen_string_literal: true
+
+return if RUBY_ENGINE == "jruby"
+
+require_relative "test_helper"
+
+begin
+  require "ruby_parser"
+rescue LoadError
+  # In CRuby's CI, we're not going to test against the ruby_parser gem because
+  # we don't want to have to install it. So in this case we'll just skip this
+  # test.
+  return
+end
+
+# We want to also compare lines and files to make sure we're setting them
+# correctly.
+Sexp.prepend(
+  Module.new do
+    def ==(other)
+      super && line == other.line && max_line == other.max_line && file == other.file
+    end
+  end
+)
+
+module Prism
+  class RubyParserTest < TestCase
+    base = File.join(__dir__, "fixtures")
+
+    todos = %w[
+      heredocs_nested.txt
+      newline_terminated.txt
+      seattlerb/bug169.txt
+      seattlerb/dstr_evstr.txt
+      seattlerb/heredoc_squiggly_interp.txt
+      seattlerb/masgn_colon3.txt
+      seattlerb/messy_op_asgn_lineno.txt
+      seattlerb/op_asgn_primary_colon_const_command_call.txt
+      seattlerb/parse_line_evstr_after_break.txt
+      seattlerb/regexp_esc_C_slash.txt
+      seattlerb/str_lit_concat_bad_encodings.txt
+      seattlerb/str_pct_nested_nested.txt
+      unescaping.txt
+      unparser/corpus/literal/kwbegin.txt
+      unparser/corpus/literal/send.txt
+      unparser/corpus/semantic/dstr.txt
+      whitequark/masgn_const.txt
+      whitequark/ruby_bug_12402.txt
+      whitequark/ruby_bug_14690.txt
+      whitequark/space_args_block.txt
+      whitequark/string_concat.txt
+    ]
+
+    # These files contain CRLF line endings, which ruby_parser translates into
+    # LF before it gets back to the node. This means the node actually has the
+    # wrong contents.
+    crlf = %w[
+      dos_endings.txt
+      heredoc_with_comment.txt
+      seattlerb/heredoc__backslash_dos_format.txt
+      seattlerb/heredoc_with_carriage_return_escapes_windows.txt
+      seattlerb/heredoc_with_extra_carriage_horrible_mix.txt
+      seattlerb/heredoc_with_extra_carriage_returns_windows.txt
+      seattlerb/heredoc_with_extra_carriage_returns.txt
+      seattlerb/heredoc_with_interpolation_and_carriage_return_escapes_windows.txt
+      seattlerb/heredoc_with_only_carriage_returns_windows.txt
+      seattlerb/heredoc_with_only_carriage_returns.txt
+    ]
+
+    # https://github.com/seattlerb/ruby_parser/issues/344
+    failures = crlf | %w[
+      alias.txt
+      method_calls.txt
+      methods.txt
+      not.txt
+      patterns.txt
+      regex.txt
+      seattlerb/and_multi.txt
+      seattlerb/heredoc_bad_hex_escape.txt
+      seattlerb/heredoc_bad_oct_escape.txt
+      spanning_heredoc_newlines.txt
+      spanning_heredoc.txt
+      tilde_heredocs.txt
+      unparser/corpus/literal/literal.txt
+      while.txt
+      whitequark/class_definition_in_while_cond.txt
+      whitequark/cond_eflipflop.txt
+      whitequark/cond_iflipflop.txt
+      whitequark/cond_match_current_line.txt
+      whitequark/dedenting_heredoc.txt
+      whitequark/if_while_after_class__since_32.txt
+      whitequark/lvar_injecting_match.txt
+      whitequark/not.txt
+      whitequark/op_asgn_cmd.txt
+      whitequark/parser_slash_slash_n_escaping_in_literals.txt
+      whitequark/pattern_matching_single_line_allowed_omission_of_parentheses.txt
+      whitequark/pattern_matching_single_line.txt
+      whitequark/ruby_bug_11989.txt
+      whitequark/slash_newline_in_heredocs.txt
+    ]
+
+    Dir["**/*.txt", base: base].each do |name|
+      next if failures.include?(name)
+
+      define_method("test_#{name}") do
+        begin
+          # Parsing with ruby parser tends to be noisy with warnings, so we're
+          # turning those off.
+          previous_verbose, $VERBOSE = $VERBOSE, nil
+          assert_parse_file(base, name, todos.include?(name))
+        ensure
+          $VERBOSE = previous_verbose
+        end
+      end
+    end
+
+    private
+
+    def assert_parse_file(base, name, allowed_failure)
+      filepath = File.join(base, name)
+      expected = ::RubyParser.new.parse(File.read(filepath), filepath)
+      actual = Prism::Translation::RubyParser.parse_file(filepath)
+
+      if !allowed_failure
+        assert_equal_nodes expected, actual
+      elsif expected == actual
+        puts "#{name} now passes"
+      end
+    end
+
+    def assert_equal_nodes(left, right)
+      return if left == right
+
+      if left.is_a?(Sexp) && right.is_a?(Sexp)
+        if left.line != right.line
+          assert_equal "(#{left.inspect} line=#{left.line})", "(#{right.inspect} line=#{right.line})"
+        elsif left.file != right.file
+          assert_equal "(#{left.inspect} file=#{left.file})", "(#{right.inspect} file=#{right.file})"
+        elsif left.length != right.length
+          assert_equal "(#{left.inspect} length=#{left.length})", "(#{right.inspect} length=#{right.length})"
+        else
+          left.zip(right).each { |l, r| assert_equal_nodes(l, r) }
+        end
+      else
+        assert_equal left, right
+      end
+    end
+  end
+end