tests: provide global vars distinguishing platforms

tests/run.rb

@@ -21,7 +21,11 @@ rescue
 end
 
 def setup
-  ENV[ /darwin/i.match(RUBY_PLATFORM) ? 'LANG' : 'LC_ALL' ] = 'en_US.UTF-8'
+  $is_windows = %r{win|mingw}i.match(RUBY_PLATFORM)
+  $is_macos   = %r{darwin}i.match(RUBY_PLATFORM)
+  $is_linux   = !$is_windows && !$is_macos
+
+  ENV[ $is_macos ? 'LANG' : 'LC_ALL' ] = 'en_US.UTF-8'
   ENV['PATH']                          = "../src:" + ENV['PATH']
 
   $config = read_build_config

tests/test.d/controller.rb

@@ -19,7 +19,7 @@ class Controller
 
   def get_num_processors
     np = case RUBY_PLATFORM
-         when /darwin/ then `/usr/sbin/sysctl -n hw.availcpu`.to_i
+         when $is_macos then `/usr/sbin/sysctl -n hw.availcpu`.to_i
          else                `nproc`.to_i
          end
     [ np, 0 ].max + 1

tests/test.d/test.rb

@@ -12,8 +12,7 @@ class Test
     @debug_commands = Array.new
 
     # install md5 handler
-    case RUBY_PLATFORM
+    if $is_macos
-      when /darwin/
       @md5 = lambda do |name|
         @debug_commands << "/sbin/md5 #{name}"
         `/sbin/md5 #{name}`.chomp.gsub(/.*=\s*/, "")

tests/test.d/util.rb

@@ -42,8 +42,7 @@ class String
 end
 
 # install md5 handler
-case RUBY_PLATFORM
+if $is_macos
-when /darwin/
   def md5 name
     `/sbin/md5 #{name}`.chomp.gsub(/.*=\s*/, "")
   end