JSON::Pure fix strict mode

Followup: #519
Fix: #584

lib/json/pure/generator.rb

@@ -354,7 +354,7 @@ def json_transform(state)
               result << delim unless first
               result << state.indent * depth if indent
               result = "#{result}#{key.to_s.to_json(state)}#{state.space_before}:#{state.space}"
-              if state.strict?
+              if state.strict? && !(!value || value == true || value.is_a?(Array) || value.is_a?(Integer) || value.is_a?(Float) || value.is_a?(String))
                 raise GeneratorError, "#{value.class} not allowed in JSON"
               elsif value.respond_to?(:to_json)
                 result << value.to_json(state)
@@ -397,7 +397,7 @@ def json_transform(state)
             each { |value|
               result << delim unless first
               result << state.indent * depth if indent
-              if state.strict?
+              if state.strict? && !(!value || value == true || value.is_a?(Array) || value.is_a?(Integer) || value.is_a?(Float) || value.is_a?(String))
                 raise GeneratorError, "#{value.class} not allowed in JSON"
               elsif value.respond_to?(:to_json)
                 result << value.to_json(state)

tests/json_generator_test.rb

@@ -67,6 +67,24 @@ def test_dump_unenclosed_hash
 
   def test_dump_strict
     assert_equal '{}', dump({}, strict: true)
+
+    assert_equal '{"array":[42,4.2,"forty-two",true,false,null]}', dump({
+      "array" => [42, 4.2, "forty-two", true, false, nil] 
+    }, strict: true)
+
+    assert_equal '{"int":42,"float":4.2,"string":"forty-two","true":true,"false":false,"nil":null}', dump({
+      "int" => 42,
+      "float" => 4.2,
+      "string" => "forty-two",
+      "true" => true,
+      "false" => false,
+      "nil" => nil,
+    }, strict: true)
+
+    assert_equal '[]', dump([], strict: true)
+
+    assert_equal '42', dump(42, strict: true)
+    assert_equal 'true', dump(true, strict: true)
   end
 
   def test_generate_pretty