[assessment-tool] Allow null value for position.

2 files changed, 28 insertions, 1 deletions

diff --git a/3party/jansson/myjansson.cpp b/3party/jansson/myjansson.cpp
index 2987c51f17..5adab297c9 100644
--- a/3party/jansson/myjansson.cpp
+++ b/3party/jansson/myjansson.cpp
@@ -50,6 +50,8 @@ json_t * GetJSONOptionalField(json_t * root, std::string const & field)
     MYTHROW(my::Json::Exception, ("Bad json object while parsing", field));
   return json_object_get(root, field.c_str());
 }
+
+bool JSONIsNull(json_t * root) { return json_is_null(root); }
 }  // namespace my
 
 void FromJSONObject(json_t * root, string const & field, double & result)
@@ -157,7 +159,7 @@ void ToJSONObject(json_t & root, string const & field, string const & value)
 void FromJSONObjectOptionalField(json_t * root, string const & field, string & result)
 {
   auto * val = my::GetJSONOptionalField(root, field);
-  if (!val)
+  if (!val || my::JSONIsNull(val))
   {
     result.clear();
     return;
diff --git a/3party/jansson/myjansson.hpp b/3party/jansson/myjansson.hpp
index 7b68c4211e..e5657d120d 100644
--- a/3party/jansson/myjansson.hpp
+++ b/3party/jansson/myjansson.hpp
@@ -45,6 +45,7 @@ public:
 
 json_t * GetJSONObligatoryField(json_t * root, std::string const & field);
 json_t * GetJSONOptionalField(json_t * root, std::string const & field);
+bool JSONIsNull(json_t * root);
 }  // namespace my
 
 inline void FromJSON(json_t * root, json_t *& value) { value = root; }
@@ -82,6 +83,30 @@ void FromJSONObject(json_t * root, std::string const & field, std::vector<T> & r
     FromJSON(json_array_get(arr, i), result[i]);
 }
 
+// The function tries to parse array of values from a value
+// corresponding to |field| in a json object corresponding to |root|.
+// Returns true when the value is non-null and array is successfully
+// parsed.  Returns false when there are no such |field| in a |root|
+// or value is null.  Also, the method may throw exception in case of
+// json parsing errors.
+template <typename T>
+bool FromJSONObjectOptional(json_t * root, std::string const & field, std::vector<T> & result)
+{
+  auto * arr = my::GetJSONOptionalField(root, field);
+  if (!arr || my::JSONIsNull(arr))
+  {
+    result.clear();
+    return false;
+  }
+  if (!json_is_array(arr))
+    MYTHROW(my::Json::Exception, ("The field", field, "must contain a json array."));
+  size_t const sz = json_array_size(arr);
+  result.resize(sz);
+  for (size_t i = 0; i < sz; ++i)
+    FromJSON(json_array_get(arr, i), result[i]);
+  return true;
+}
+
 template <typename T>
 void ToJSONObject(json_t & root, std::string const & field, std::vector<T> const & values)
 {