Refactor ERB version checking for keyword arguments

Improving code like r62590. See r62529 for details.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@62594 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

enc/make_encmake.rb

@@ -121,7 +121,7 @@ ENCS, ENC_DEPS = target_encodings
 ATRANS, TRANS = target_transcoders
 
 if File.exist?(depend = File.join($srcdir, "depend"))
-  if ERB.version[/\d+\.\d+/] >= '2.2'
+  if ERB.instance_method(:initialize).parameters.assoc(:key) # Ruby 2.6+
     erb = ERB.new(File.read(depend), trim_mode: '%')
   else
     erb = ERB.new(File.read(depend), nil, '%')
@@ -139,7 +139,7 @@ open(ARGV[0], 'wb') {|f|
 }
 if MODULE_TYPE == :static
   filename = "encinit.c.erb"
-  if ERB.version[/\d+\.\d+/] >= '2.2'
+  if ERB.instance_method(:initialize).parameters.assoc(:key) # Ruby 2.6+
     erb = ERB.new(File.read(File.join($srcdir, filename)), trim_mode: '%-')
   else
     erb = ERB.new(File.read(File.join($srcdir, filename)), nil, '%-')

ext/etc/mkconstants.rb

@@ -67,7 +67,7 @@ def each_name(pat)
 end
 
 erb_new = lambda do |src, safe, trim|
-  if RUBY_VERSION >= '2.6'
+  if ERB.instance_method(:initialize).parameters.assoc(:key) # Ruby 2.6+
     ERB.new(src, trim_mode: trim)
   else
     ERB.new(src, safe, trim)

ext/socket/mkconstants.rb

@@ -74,7 +74,7 @@ def each_name(pat)
 end
 
 erb_new = lambda do |src, safe, trim|
-  if RUBY_VERSION >= '2.6'
+  if ERB.instance_method(:initialize).parameters.assoc(:key) # Ruby 2.6+
     ERB.new(src, trim_mode: trim)
   else
     ERB.new(src, safe, trim)

tool/generic_erb.rb

@@ -34,8 +34,7 @@ unchanged = color.pass("unchanged")
 updated = color.fail("updated")
 
 result = templates.map do |template|
-  match = ERB.version.match(/\Aerb\.rb \[(?<version>[^ ]+) /)
-  if match && match[:version] >= '2.2.0' # Ruby 2.6+
+  if ERB.instance_method(:initialize).parameters.assoc(:key) # Ruby 2.6+
     erb = ERB.new(File.read(template), trim_mode: '%-')
   else
     erb = ERB.new(File.read(template), nil, '%-')

tool/ruby_vm/helpers/dumper.rb

@@ -32,8 +32,7 @@ class RubyVM::Dumper
   rescue Errno::ENOENT
     raise "don't know how to generate #{path}"
   else
-    match = ERB.version.match(/\Aerb\.rb \[(?<version>[^ ]+) /)
-    if match && match[:version] >= '2.2.0' # Ruby 2.6+
+    if ERB.instance_method(:initialize).parameters.assoc(:key) # Ruby 2.6+
       erb = ERB.new(src, trim_mode: '%-')
     else
       erb = ERB.new(src, nil, '%-')

tool/transcode-tblgen.rb

@@ -1078,7 +1078,7 @@ if __FILE__ == $0
   end
 
   libs1 = $".dup
-  if ERB.version[/\d+\.\d+/] >= '2.2'
+  if ERB.instance_method(:initialize).parameters.assoc(:key) # Ruby 2.6+
     erb = ERB.new(src, trim_mode: '%')
   else
     erb = ERB.new(src, nil, '%')