Make config object method_missing more robust

lib/prawn-rails/config.rb

@@ -5,13 +5,19 @@ class Config < HashWithIndifferentAccess
     def method_missing(method_name, *args)
       # to replace behaviour of previous openstruct-based configuration object
 
-      method_name = method_name.to_s
+      if method_name.to_s.end_with?("=")
+        if args.size >= 2
+          super # raise normal exception
+        end
 
-      if method_name.end_with?("=")
-        key = method_name.sub(/=$/, "")
+        key = method_name.to_s.sub(/=$/, "")
         self[key] = args.first
       else
-        self[method_name]
+        if args.any?
+          super # raise normal exception
+        else
+          self[method_name]
+        end
       end
     end
   end

test/unit/config_test.rb

@@ -3,23 +3,23 @@
 class ConfigTest < ActiveSupport::TestCase
 
   def setup
-    @original_config = PrawnRails.config.to_h
+    @original_config = PrawnRails.config.clone
   end
 
   def teardown
     PrawnRails.config do |config|
-      config.to_h.keys.each do |key|
-        config.delete_field(key)
+      config.keys.each do |key|
+        config.delete(key)
       end
 
-      @original_config.to_h.each do |k,v|
+      @original_config.each do |k,v|
         config[k] = v
       end
     end
   end
 
   test "has a default config" do
-    assert_equal PrawnRails.config.to_h.symbolize_keys, {page_layout: :portrait, page_size: "A4", skip_page_creation: false}
+    assert_equal PrawnRails.config.symbolize_keys, {page_layout: :portrait, page_size: "A4", skip_page_creation: false}
   end
 
   test "config can be set with block syntax" do
@@ -28,7 +28,26 @@ def teardown
       config.page_size = "A8"
     end
 
-    assert_equal PrawnRails.config.to_h.symbolize_keys, {page_layout: :landscape, page_size: "A8", skip_page_creation: false}
+    assert_equal PrawnRails.config.symbolize_keys, {page_layout: :landscape, page_size: "A8", skip_page_creation: false}
+  end
+
+  test "allows reading any hash value via method syntax" do
+    assert_equal PrawnRails.config.foo, nil
+  end
+
+  test "allows writing any hash value via method syntax" do
+    PrawnRails.config.foo = "bar"
+    assert_equal PrawnRails.config.foo, "bar"
+  end
+
+  test "does not allow unknown methods with arguments" do
+    assert_raises NoMethodError do
+      PrawnRails.config.foo("bar")
+    end
+
+    assert_raises NoMethodError do
+      PrawnRails.config.send("foo=", "bar", "baz")
+    end
   end
 
 end

test/unit/document_test.rb

@@ -19,13 +19,13 @@ def read_pdf_str(str)
 
   class ConfigTest < DocumentTest
     def setup
-      @original_config = PrawnRails.config.to_h
+      @original_config = PrawnRails.config.clone
     end
 
     def teardown
       PrawnRails.config do |config|
         config.to_h.keys.each do |key|
-          config.delete_field(key)
+          config.delete(key)
         end
 
         @original_config.to_h.each do |k,v|