diff --git a/src/json.cc b/src/json.cc index f2c4456c..33cf0062 100644 --- a/src/json.cc +++ b/src/json.cc @@ -492,7 +492,7 @@ std::string json::dump(const bool prettyPrint, const unsigned int indentStep, { case (value_type::string): { - return std::string("\"") + *value_.string + "\""; + return std::string("\"") + escapeString(*value_.string) + "\""; } case (value_type::boolean): @@ -589,6 +589,49 @@ std::string json::dump(const bool prettyPrint, const unsigned int indentStep, } } +/*! +Internal function to replace all occurrences of a character in a given string +with another string. + +\param str the string that contains tokens to replace +\param c the character that needs to be replaced +\param replacement the string that is the replacement for the character +*/ +void json::replaceChar(std::string& str, char c, const std::string& replacement) + const +{ + size_t start_pos = 0; + while((start_pos = str.find(c, start_pos)) != std::string::npos) { + str.replace(start_pos, 1, replacement); + start_pos += replacement.length(); + } +} + +/*! +Escapes all special characters in the given string according to ECMA-404. +Necessary as some characters such as quotes, backslashes and so on +can't be used as is when dumping a string value. + +\param str the string that should be escaped. + +\return a copy of the given string with all special characters escaped. +*/ +std::string json::escapeString(const std::string& str) const +{ + std::string result(str); + // we first need to escape the backslashes as all other methods will insert + // legitimate backslashes into the result. + replaceChar(result, '\\', "\\\\"); + // replace all other characters + replaceChar(result, '"', "\\\""); + replaceChar(result, '\n', "\\n"); + replaceChar(result, '\r', "\\r"); + replaceChar(result, '\f', "\\f"); + replaceChar(result, '\b', "\\b"); + replaceChar(result, '\t', "\\t"); + return result; +} + /*! Serialization function for JSON objects. The function tries to mimick Python's \p json.dumps() function, and currently supports its \p indent parameter. diff --git a/src/json.h b/src/json.h index 2dd99348..59a57b84 100644 --- a/src/json.h +++ b/src/json.h @@ -165,7 +165,10 @@ class json /// dump the object (with pretty printer) std::string dump(const bool, const unsigned int, unsigned int = 0) const noexcept; - + /// replaced a character in a string with another string + void replaceChar(std::string& str, char c, const std::string& replacement) const; + /// escapes special characters to safely dump the string + std::string escapeString(const std::string&) const; public: /// explicit value conversion template diff --git a/test/json_unit.cc b/test/json_unit.cc index b2fcd65e..a894c0a8 100644 --- a/test/json_unit.cc +++ b/test/json_unit.cc @@ -819,6 +819,17 @@ TEST_CASE("string") j1.clear(); CHECK(j1.get() == ""); } + + SECTION("Dumping") + { + CHECK(json("\"").dump(0) == "\"\\\"\""); + CHECK(json("\\").dump(0) == "\"\\\\\""); + CHECK(json("\n").dump(0) == "\"\\n\""); + CHECK(json("\t").dump(0) == "\"\\t\""); + CHECK(json("\b").dump(0) == "\"\\b\""); + CHECK(json("\f").dump(0) == "\"\\f\""); + CHECK(json("\r").dump(0) == "\"\\r\""); + } } TEST_CASE("boolean")