Add an option to supress Parser gem compatibility warnings

Author: Nu-hin

CHANGELOG.md

@@ -23,6 +23,7 @@
 * Only two adapters are now available: SSH adapter, and local temp file adapter. All other adapters are deprecated.
 * Cache directory is now a [global configuration option](README.md#configuration), rather than an argument to the ExecutionContext.
 * The default cache location is now in the .remote_ruby/cache, relative to the working directory.
+* Added a possibility to suppress [Parser warnings](https://github.com/whitequark/parser#compatibility-with-ruby-mri).
 * Added [changelog](#CHANGELOG.md)
 
 ### Migration from v0.3

README.md

@@ -144,6 +144,11 @@ RemoteRuby.configure do |c|
   # `dump_code` is set to `true` in the ExecutionContext.
   # By default code is saved to .remote_ruby/code (relative to the working directory).
   c.code_dir = File.join(Dir.pwd, '.remote_ruby/code')
+
+  # Set to true if you don't want to see warnings about parser gem compatibility with
+  # current Ruby version.
+  # False by default.
+  c.suppress_parser_warnings = false
 end
 ```
 

lib/remote_ruby.rb

@@ -13,7 +13,7 @@ module RemoteRuby
 
   class << self
     attr_reader :plugins, :ignored_types
-    attr_accessor :cache_dir, :code_dir
+    attr_accessor :cache_dir, :code_dir, :suppress_parser_warnings
 
     def root(*params)
       root_dir = ::Gem::Specification.find_by_name('remote_ruby').gem_dir
@@ -63,5 +63,7 @@ def configure
 
   config.ignore_types RemoteRuby::ExecutionContext
 
+  config.suppress_parser_warnings = false
+
   config.register_plugin(:rails, RemoteRuby::RailsPlugin)
 end

lib/remote_ruby/parser_factory.rb

@@ -0,0 +1,29 @@
+# frozen_string_literal: true
+
+module RemoteRuby
+  # Serves to dynamically require the parser gem and configure it.
+  # This is done in a separate module to have a possibility
+  # to suppress parser gem warnings about Ruby compatibility.
+  module ParserFactory
+    def self.require_parser
+      begin
+        prev = $VERBOSE
+        $VERBOSE = nil if RemoteRuby.suppress_parser_warnings
+        require 'parser/current'
+        require 'unparser'
+      ensure
+        $VERBOSE = prev
+      end
+
+      # Opt-in to most recent AST format
+      Parser::Builders::Default.emit_lambda              = true
+      Parser::Builders::Default.emit_procarg0            = true
+      Parser::Builders::Default.emit_encoding            = true
+      Parser::Builders::Default.emit_index               = true
+      Parser::Builders::Default.emit_arg_inside_procarg0 = true
+      Parser::Builders::Default.emit_forward_arg         = true
+      Parser::Builders::Default.emit_kwargs              = true
+      Parser::Builders::Default.emit_match_pattern       = true
+    end
+  end
+end

lib/remote_ruby/source_extractor.rb

@@ -1,24 +1,14 @@
 # frozen_string_literal: true
 
 require 'method_source'
-require 'parser/current'
-require 'unparser'
-
-# Opt-in to most recent AST format
-Parser::Builders::Default.emit_lambda              = true
-Parser::Builders::Default.emit_procarg0            = true
-Parser::Builders::Default.emit_encoding            = true
-Parser::Builders::Default.emit_index               = true
-Parser::Builders::Default.emit_arg_inside_procarg0 = true
-Parser::Builders::Default.emit_forward_arg         = true
-Parser::Builders::Default.emit_kwargs              = true
-Parser::Builders::Default.emit_match_pattern       = true
+require 'remote_ruby/parser_factory'
 
 module RemoteRuby
   # Receives a block and extracts Ruby code (as a string) with this block's
   # source
   class SourceExtractor
     def extract(&block)
+      RemoteRuby::ParserFactory.require_parser
       ast = Parser::CurrentRuby.parse(block.source)
       block_node = find_block(ast)