refactor: move platform detection to Rake module

The Rake::Win32 module existed solely to answer one question: are we
running on Windows? That single-method module was more ceremony than it
was worth, and it meant platform detection was split across two places —
Win32.windows? in win32.rb and Application#unix? in application.rb.

Both methods now live together as Rake.windows? and Rake.unix? on the
Rake module itself, which is the natural home for gem-level helpers.

Application#windows? and Application#unix? are kept as thin delegators
so nothing calling them through an application instance breaks.

Author: pvdb

lib/rake.rb

@@ -33,8 +33,6 @@ module Rake; end
 
 require_relative "rake/ext/string"
 
-require_relative "rake/win32"
-
 require_relative "rake/linked_list"
 require_relative "rake/cpu_counter"
 require_relative "rake/scope"

lib/rake/application.rb

@@ -7,7 +7,6 @@
 require_relative "thread_pool"
 require_relative "thread_history_display"
 require_relative "trace_output"
-require_relative "win32"
 
 module Rake
 
@@ -384,12 +383,11 @@ def dynamic_width_tput # :nodoc:
     end
 
     def unix? # :nodoc:
-      RbConfig::CONFIG["host_os"] =~
-        /(aix|darwin|linux|(net|free|open)bsd|cygwin|solaris|irix|hpux)/i
+      Rake.unix?
     end
 
     def windows? # :nodoc:
-      Win32.windows?
+      Rake.windows?
     end
 
     def truncate(string, width) # :nodoc:

lib/rake/rake_module.rb

@@ -14,6 +14,17 @@ def application=(app)
       @application = app
     end
 
+    # True if running on a Windows system.
+    def windows?
+      RbConfig::CONFIG["host_os"] =~ %r!(msdos|mswin|djgpp|mingw|[Ww]indows)!
+    end
+
+    # True if running on a Unix system.
+    def unix?
+      RbConfig::CONFIG["host_os"] =~
+        /(aix|darwin|linux|(net|free|open)bsd|cygwin|solaris|irix|hpux)/i
+    end
+
     def suggested_thread_count # :nodoc:
       @cpu_count ||= Rake::CpuCounter.count
       @cpu_count + 4

lib/rake/win32.rb

@@ -90,7 +90,6 @@ Gem::Specification.new do |s|
     "lib/rake/thread_pool.rb",
     "lib/rake/trace_output.rb",
     "lib/rake/version.rb",
-    "lib/rake/win32.rb",
     "rake.gemspec"
   ]
   s.bindir = "exe"

rake.gemspec

@@ -38,4 +38,11 @@ def test_original_dir_reports_current_dir
     assert_equal @tempdir, Rake.original_dir
   end
 
+  def test_platform_detection
+    # ensure that Rake's platform detection logic
+    # is mutually exclusive, and doesn't claim to
+    # be both Windows and Unix at the same time
+    assert ! (Rake.windows? && Rake.unix?)
+  end
+
 end

test/test_rake.rb

@@ -419,8 +419,16 @@ def test_terminal_columns
     end
   end
 
-  def test_windows
-    assert ! (@app.windows? && @app.unix?)
+  if Rake.unix?
+    def test_unix_platform_detection
+      assert @app.unix?
+    end
+  end
+
+  if Rake.windows?
+    def test_windows_platform_detection
+      assert @app.windows?
+    end
   end
 
   def test_loading_imports

test/test_rake_application.rb

@@ -27,13 +27,15 @@ def test_directory
     refute File.exist?("a/b/c")
   end
 
-  def test_directory_colon
-    directory "a:b"
+  if Rake.unix?
+    def test_directory_colon
+      directory "a:b"
 
-    assert_equal FileCreationTask, Task["a:b"].class
-  end unless Rake::Win32.windows?
+      assert_equal FileCreationTask, Task["a:b"].class
+    end
+  end
 
-  if Rake::Win32.windows?
+  if Rake.windows?
     def test_directory_win32
       desc "WIN32 DESC"
       directory "c:/a/b/c"

test/test_rake_directory_task.rb

@@ -349,8 +349,8 @@ def test_string_ext
     assert_equal ".one", ".one".ext
     assert_equal ".", ".".ext("c")
     assert_equal "..", "..".ext("c")
-    # These only need to work in windows
-    if Rake::Win32.windows?
+    # These only need to work on Windows
+    if Rake.windows?
       assert_equal "one.x\\two.net", "one.x\\two.c".ext(".net")
       assert_equal "one.x\\two.net", "one.x\\two".ext(".net")
     end