Add bump:dev and bump:pre tasks

rakelib/version.rake

@@ -21,23 +21,72 @@ class << (helper = Bundler::GemHelper.instance)
     update_gemspec
     commit_bump
   end
+
+  def next_dev
+    v = gemspec.version.segments
+    if v.size > 4
+      v[-1] = v[-1].succ
+    else
+      v[2] = v[2].succ if v.size == 3
+      v[3..-1] = "dev.1"
+    end
+    Gem::Version.new(v.join("."))
+  end
+
+  def next_preview
+    v = gemspec.version.segments
+    if v[3] == "pre"
+      v[-1] = v[-1].succ
+    else
+      v[3..-1] = "pre.1"
+    end
+    Gem::Version.new(v.join("."))
+  end
+
+  def next_release
+    if gemspec.version.prerelease?
+      gemspec.version.release
+    else
+      v = gemspec.version.segments[0, 3]
+      v[-1] = v[-1].succ
+      Gem::Version.new(v.join("."))
+    end
+  end
+
+  def next_minor
+    major, minor = gemspec.version.segments
+    Gem::Version.new("#{major}.#{minor+1}.0")
+  end
+
+  def next_major
+    major, = gemspec.version.segments
+    Gem::Version.new("#{major+1}.0.0")
+  end
+end
+
+desc "Bump to development"
+task "bump:dev" do
+  helper.version = helper.next_dev
 end
 
-major, minor, teeny = helper.gemspec.version.segments
+desc "Bump to prerelease"
+task "bump:pre" do
+  helper.version = helper.next_preview
+end
 
 desc "Bump teeny version"
 task "bump:teeny" do
-  helper.version = Gem::Version.new("#{major}.#{minor}.#{teeny+1}")
+  helper.version = helper.next_release
 end
 
 desc "Bump minor version"
 task "bump:minor" do
-  helper.version = Gem::Version.new("#{major}.#{minor+1}.0")
+  helper.version = helper.next_minor
 end
 
 desc "Bump major version"
 task "bump:major" do
-  helper.version = Gem::Version.new("#{major+1}.0.0")
+  helper.version = helper.next_major
 end
 
 desc "Bump teeny version"