Implement version bump

Rakefile

@@ -79,3 +79,90 @@ RDoc::Task.new do |rdoc|
     rdoc.rdoc_files.include(file) if File.exist?(file)
   }
 end
+
+def change_version(&block)
+  version_file = 'lib/net/scp/version.rb'
+  require_relative version_file
+  pre = Net::SCP::Version::PRE
+  tiny = Net::SCP::Version::TINY
+  result = block[pre: pre, tiny: Net::SCP::Version::TINY]
+  raise ArgumentError, "Version change logic should always return a pre" unless result.key?(:pre)
+
+  new_pre = result[:pre]
+  new_tiny = result[:tiny] || tiny
+  found = { pre: false, tiny: false }
+  File.open("#{version_file}.new", "w") do |f|
+    File.readlines(version_file).each do |line|
+      match =
+        if pre.nil?
+          /^(\s+PRE\s+=\s+)nil(\s*)$/.match(line)
+        else
+          /^(\s+PRE\s+=\s+")#{pre}("\s*)$/.match(line)
+        end
+      if match
+        prefix = match[1]
+        postfix = match[2]
+        prefix.delete_suffix!('"')
+        postfix.delete_prefix!('"')
+        new_line = "#{prefix}#{new_pre.inspect}#{postfix}"
+        puts "Changing:\n  - #{line}  + #{new_line}"
+        line = new_line
+        found[:pre] = true
+      end
+
+      if new_tiny != tiny
+        match = /^(\s+TINY\s+=\s+)#{tiny}(\s*)$/.match(line)
+        if match
+          prefix = match[1]
+          postfix = match[2]
+          new_line = "#{prefix}#{new_tiny}#{postfix}"
+          puts "Changing:\n  - #{line}  + #{new_line}"
+          line = new_line
+          found[:tiny] = true
+        end
+      end
+
+      f.write(line)
+    end
+    raise ArgumentError, "Cound not find line: PRE = \"#{pre}\" in #{version_file}" unless found[:pre]
+    raise ArgumentError, "Cound not find line: TINY = \"#{tiny}\" in #{version_file}" unless found[:tiny] || new_tiny == tiny
+  end
+
+  FileUtils.mv version_file, "#{version_file}.old"
+  FileUtils.mv "#{version_file}.new", version_file
+end
+
+namespace :vbump do
+  desc "Final release"
+  task :final do
+    change_version do |pre:, tiny:|
+      _ = tiny
+      if pre.nil?
+        { tiny: tiny + 1, pre: nil }
+      else
+        raise ArgumentError, "Unexpected pre: #{pre}" if pre.nil?
+
+        { pre: nil }
+      end
+    end
+  end
+
+  desc "Increment prerelease"
+  task :pre, [:type] do |_t, args|
+    change_version do |pre:, tiny:|
+      puts " PRE => #{pre.inspect}"
+      match = /^([a-z]+)(\d+)/.match(pre)
+      raise ArgumentError, "Unexpected pre: #{pre}" if match.nil? && args[:type].nil?
+
+      if match.nil? || (!args[:type].nil? && args[:type] != match[1])
+        if pre.nil?
+          { pre: "#{args[:type]}1", tiny: tiny + 1 }
+        else
+          { pre: "#{args[:type]}1" }
+        end
+      else
+        { pre: "#{match[1]}#{match[2].to_i + 1}" }
+      end
+    end
+  end
+end