validate the data before initializing config to fail fast

lib/attributor/flatpack/config.rb

@@ -37,7 +37,19 @@ def self.example(context = nil, **values)
         example
       end
 
+      def self.validate_data(data)
+        return true unless data.respond_to?(:keys)
+
+        data.keys.each do |k|
+          /(.)*/.match?(k)
+        rescue TypeError => e
+          raise ArgumentError, 'keys must be symboles or strings'
+        end
+      end
+
       def initialize(data = nil)
+        self.class.validate_data data
+
         @raw = data
         @contents = {}
 
@@ -171,7 +183,7 @@ def validate_requirements(context)
 
       def validate_keys(context)
         return [] if self.class.options[:allow_extra]
-
+        
         errors = (@raw.keys.collect(&:to_s) - self.class.keys.keys.collect(&:to_s)).collect do |extra_key|
           "Unknown key received: #{extra_key.inspect} for #{Attributor.humanize_context(context)}"
         end

spec/attributor/flatpack/config_spec.rb

@@ -240,4 +240,16 @@
       it { should_not be_empty }
     end
   end
+
+  context 'with data with invalid keys' do
+    let(:data) do
+      {
+        { foo: :baz } => :bar
+        :foo => :bar
+      }
+    end
+    it 'should fail to initialize' do
+      expect { subject }.to raise_error(ArgumentError)
+    end
+  end
 end