Restore tolerant cache loading

lib/readthis/serializers.rb

@@ -68,6 +68,8 @@ def reset!
     #
     # @param [Object] Look up a flag by object
     # @return [Number] Corresponding flag for the serializer object
+    # @raise [UnknownSerializerError] Indicates that a serializer was
+    #   specified, but hasn't been configured for usage.
     #
     # @example
     #
@@ -88,18 +90,20 @@ def assoc(serializer)
     # @param [Number] Flag to look up the serializer object by
     # @return [Module] The serializer object
     #
+    # @example
+    #
+    #   serializers.rassoc(1) #=> Marshal
+    #
     def rassoc(flag)
-      serializer = inverted[flag]
-
-      unless serializer
-        fail UnknownSerializerError, "'#{flag}' doesn't match any serializers"
-      end
-
-      serializer
+      inverted[flag]
     end
 
-    private
+    # @private
+    def marshals
+      serializers.keys
+    end
 
+    # @private
     def flags
       serializers.values
     end

spec/readthis/serializers_spec.rb

@@ -10,16 +10,16 @@
 
       serializers << CustomSerializer
 
-      expect(serializers.serializers.keys).to include(CustomSerializer)
-      expect(serializers.serializers.values).to eq([1, 2, 3, 4])
+      expect(serializers.marshals).to include(CustomSerializer)
+      expect(serializers.flags).to eq([1, 2, 3, 4])
     end
 
     it 'increments flags' do
       serializers = Readthis::Serializers.new
       serializers << CustomSerializer
       serializers << AnotherSerializer
 
-      expect(serializers.serializers.values).to eq((1..5).to_a)
+      expect(serializers.flags).to eq((1..5).to_a)
     end
 
     it 'prevents more than seven serializers' do
@@ -53,14 +53,6 @@
 
       expect(serializers.rassoc(1)).to eq(Marshal)
     end
-
-    it 'raises a helpful error when the flag is unknown' do
-      serializers = Readthis::Serializers.new
-
-      expect do
-        serializers.rassoc(5)
-      end.to raise_error(Readthis::UnknownSerializerError)
-    end
   end
 
   describe '#freeze!' do