apkbuild-gem-resolver: use Array.empty?

apkbuild-gem-resolver.in

@@ -21,7 +21,7 @@ class Package
     @@augeas.load
 
     apath = '/files' + dir
-    fail if @@augeas.match("/augeas#{apath}//error").length > 0
+    fail unless @@augeas.match("/augeas#{apath}//error").empty?
 
     repos = ['main']
     repos << 'testing' if testing
@@ -271,7 +271,7 @@ class Update
 
     def check_deps
       specs, errors = Gem::SpecFetcher::fetcher.spec_for_dependency(dependency)
-      raise "Invalid gem: #{@name}-#{version}" if specs.length == 0
+      raise "Invalid gem: #{@name}-#{version}" if specs.empty?
       fail if specs.length > 1
       deps = specs[0][0].runtime_dependencies
 
@@ -285,7 +285,7 @@ class Update
         end
       end
 
-      if deps.length > 0
+      unless deps.empty?
         raise 'Undeclared dependencies in ' + @package.name + deps.inject('') {
           |s, dep| "#{s}\n#{dep.name} #{dep.requirements_list.join ' '}"
         }
@@ -293,7 +293,7 @@ class Update
     end
 
     def update
-      updated? || @obsolete_deps.length > 0 ? (
+      updated? || !@obsolete_deps.empty? ? (
         {
           :name => @package.name,
           :version => version,
@@ -331,7 +331,7 @@ update.resolve
 
 for pkg in update
   obs = pkg[:obsolete_deps]
-  obs = obs.length == 0 ? nil : " (obsolete dependencies: #{obs.join ', '})"
+  obs = obs.empty? ? nil : " (obsolete dependencies: #{obs.join ', '})"
 
   puts "#{pkg[:name]}-#{pkg[:version]}#{obs}"
 end