Extract version number from the source

nobu · hsbt · commit 1dd974a5e290 · 2020-08-03T19:07:48.000+09:00
"requiring version.rb" strategy has some issues.

- cannot work when cross-compiling
- often introduces wrong namespace
- must know the superclasses
- costs at each runtime than at build-time

etc.
diff --git a/optparse.gemspec b/optparse.gemspec
@@ -1,7 +1,8 @@
+# frozen_string_literal: true
+
 name = File.basename(__FILE__, ".gemspec")
-version = nil
-["lib", ".."].find do |dir|
-  version = File.foreach(File.join(__dir__, dir, "#{name}.rb")) do |line|
+version = ["lib", Array.new(name.count("-")+1, "..").join("/")].find do |dir|
+  break File.foreach(File.join(__dir__, dir, "#{name.tr('-', '/')}.rb")) do |line|
     /^\s*OptionParser::Version\s*=\s*"(.*)"/ =~ line and break $1
   end rescue nil
 end
