Added new kind of test: check for specific properties of AST

libsolutil/JSON.cpp

@@ -144,4 +144,19 @@ bool jsonParseStrict(std::string const& _input, Json::Value& _json, std::string*
 	return parse(readerBuilder, _input, _json, _errs);
 }
 
+std::optional<Json::Value> jsonValueByPath(Json::Value const& _node, std::string_view _jsonPath)
+{
+	if (!_node.isObject() || _jsonPath.empty())
+		return {};
+
+	std::string memberName = std::string(_jsonPath.substr(0, _jsonPath.find_first_of('.')));
+	if (!_node.isMember(memberName))
+		return {};
+
+	if (memberName == _jsonPath)
+		return _node[memberName];
+
+	return jsonValueByPath(_node[memberName], _jsonPath.substr(memberName.size() + 1));
+}
+
 } // namespace solidity::util

libsolutil/JSON.h

@@ -26,6 +26,8 @@
 #include <json/json.h>
 
 #include <string>
+#include <string_view>
+#include <optional>
 
 namespace solidity::util
 {
@@ -67,6 +69,13 @@ std::string jsonPrint(Json::Value const& _input, JsonFormat const& _format);
 /// \return \c true if the document was successfully parsed, \c false if an error occurred.
 bool jsonParseStrict(std::string const& _input, Json::Value& _json, std::string* _errs = nullptr);
 
+/// Retrieves the value specified by @p _jsonPath by from a series of nested JSON dictionaries.
+/// @param _jsonPath A dot-separated series of dictionary keys.
+/// @param _node The node representing the start of the path.
+/// @returns The value of the last key on the path. @a nullptr if any node on the path descends
+/// into something that is not a dictionary or the key is not present.
+std::optional<Json::Value> jsonValueByPath(Json::Value const& _node, std::string_view _jsonPath);
+
 namespace detail
 {