lib/bootboot/ruby_source.rb in bootboot-0.2.1 vs lib/bootboot/ruby_source.rb in bootboot-0.2.2

@@ -16,18 +16,33 @@
       end
     end
 
     def specs
       Bundler::Index.build do |idx|
-        # If the ruby version specified in the Gemfile is different from the
-        # Ruby version currently running, we want to build a definition without
-        # a lockfile (so that `ruby_version` in the Gemfile isn't overridden by
-        # the lockfile) and get its `ruby_version`. This will be used both
-        # during dependency resolution so that we can pretend the intended Ruby
-        # version is present, as well as when updating the lockfile itself.
-        ruby_version = Bundler::Definition.build(Bootboot::GEMFILE, nil, false).ruby_version
-        ruby_version ||= Bundler::RubyVersion.system
-        ruby_spec = Gem::Specification.new(ruby_spec_name, ruby_version.gem_version)
+        requested_ruby = Bundler::Definition.build(Bootboot::GEMFILE, nil, false).ruby_version
+        system_version = Bundler::RubyVersion.system.gem_version
+        requirement = Gem::Requirement.new(requested_ruby.versions) if requested_ruby
+
+        # This will be used both during dependency resolution so that we can pretend
+        # the intended Ruby version is present, as well as when updating the lock file.
+        ruby_spec_version = if requested_ruby.nil?
+          # if the Gemfile doesn't request a specific Ruby version, just use system
+          system_version
+        elsif !requirement.exact? && requirement.satisfied_by?(system_version)
+          # if the Gemfile requests a non-exact Ruby version which is satisfied by
+          # the currently running Ruby, use that when updating the lock file
+          system_version
+        else
+          # If we're here, there's either an exact requirement for the Ruby version
+          # (in which case we should substitue it instead of current Ruby version),
+          # else the currently running Ruby doesn't satisfy the non-exact requirement
+          # (in which case an error will be thrown by bundler). Not sure how we can
+          # improve the error message, which will be vague due to using #gem_version
+          # of the unsatisified requirement.
+          requested_ruby.gem_version
+        end
+
+        ruby_spec = Gem::Specification.new(ruby_spec_name, ruby_spec_version)
         ruby_spec.source = self
         idx << ruby_spec
       end
     end