Windows support.

.github/workflows/test.yaml

@@ -19,6 +19,7 @@ jobs:
         os:
           - ubuntu
           - macos
+          - windows
 
         ruby:
           - "3.2"
@@ -47,4 +48,4 @@ jobs:
 
     - name: Run tests
       timeout-minutes: 10
-      run: bundle exec bake test
+      run: bundle exec sus --verbose

lib/io/stream/buffered.rb

@@ -106,12 +106,14 @@ def sysclose
 			end
 		end
 
-		if RUBY_VERSION >= "3.3"
+		if RUBY_VERSION >= "3.3" # and RUBY_PLATFORM !~ /win32|mswin|mingw/
 			def syswrite(buffer)
 				return @io.write(buffer)
 			end
 		else
 			def syswrite(buffer)
+				raise IOError, "stream closed" if @io.closed?
+
 				while true
 					result = @io.write_nonblock(buffer, exception: false)
 
@@ -133,6 +135,8 @@ def syswrite(buffer)
 
 		# Reads data from the underlying stream as efficiently as possible.
 		def sysread(size, buffer)
+			raise IOError, "stream closed" if @io.closed?
+
 			# Come on Ruby, why couldn't this just return `nil`? EOF is not exceptional. Every file has one.
 			while true
 				result = @io.read_nonblock(size, buffer, exception: false)

test/io/stream/buffered.rb

@@ -321,6 +321,8 @@ def before
 		end
 
 		it "times out when writing" do
+			skip "#write with timeout not supported on Windows" if RUBY_PLATFORM =~ /win32|mswin|mingw/
+
 			server.io.timeout = 0.001
 
 			expect do