have_json_size raise error with non Enumerables

features/sizes.feature

@@ -35,4 +35,4 @@ Feature: Sizes
     When I get the JSON
     Then the JSON at "one" should have 1 entry
     And the JSON at "two" should have 2 values
-    And the JSON at "three" should have 3 numbers
+    And the JSON at "three" should have 3 numbers

lib/json_spec/errors.rb

@@ -31,4 +31,16 @@ def to_s
       "No JSON file at #{path}"
     end
   end
+
+  class EnumerableExpected < Error
+    attr_reader :actual_value
+
+    def initialize(actual_value)
+      @actual_value = actual_value
+    end
+
+    def to_s
+      "Enumerable expected, got #{actual_value.inspect}"
+    end
+  end
 end

lib/json_spec/matchers/have_json_size.rb

@@ -10,12 +10,9 @@ def initialize(size)
 
       def matches?(json)
         ruby = parse_json(json, @path)
-        if ruby.nil? && !@expected.nil?
-          false
-        else
-          @actual = Enumerable === ruby ? ruby.size : 1
-          @actual == @expected
-        end
+        raise EnumerableExpected.new(ruby) unless Enumerable === ruby
+        @actual = ruby.size
+        @actual == @expected
       end
 
       def at_path(path)

spec/json_spec/matchers/have_json_size_spec.rb

@@ -49,13 +49,13 @@
 
   it "provides an error when parsing nil" do
     matcher = have_json_size(0).at_path("json")
-    expect { matcher.matches?(%({"id":1,"json":null})) }.to
-      raise_error(JsonSpec::EnumerableExpected, "Enumerable expected, got nil.")
+    expect { matcher.matches?(%({"id":1,"json":null})) }.to raise_error(JsonSpec::EnumerableExpected,
+                                                                          "Enumerable expected, got nil")
   end
 
-  it "provides an error when parsing nil" do
+  it "provides an error when parsing non-enumerables" do
     matcher = have_json_size(0).at_path("json")
-    expect { matcher.matches?(%({"id":1,"json":12345})) }.to
-      raise_error(JsonSpec::EnumerableExpected, "Enumerable expected, got 12345.")
+    expect { matcher.matches?(%({"id":1,"json":12345})) }.to raise_error(JsonSpec::EnumerableExpected,
+                                                                           "Enumerable expected, got 12345")
   end
 end