Bug fix for book with no authors publishers or subjects

Gemfile.lock

@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    openlib (0.1.1)
+    openlib (0.1.2)
 
 GEM
   remote: https://rubygems.org/

lib/openlib/book.rb

@@ -37,7 +37,7 @@ module Openlib
 
     def data_data(req:)
       case req
-      when :authors, :publishers, :subjects then data.dig(req.to_s).map { |p| p.dig('name') }
+      when :authors, :publishers, :subjects then data.dig(req.to_s)&.map { |p| p.dig('name') }
       else
         data.dig(req.to_s)
       end

lib/openlib/version.rb

@@ -1,3 +1,3 @@
 module Openlib
-  VERSION = "0.1.2"
+  VERSION = "0.1.3"
 end