better handle special characters

src/parser.hpp

@@ -140,6 +140,28 @@ std::string parse_string(std::string_view& source, std::string& error) noexcept
 					value |= take_hex() << 8;
 					value |= take_hex() << 4;
 					value |= take_hex();
+					if (0xd800 <= value && value <= 0xdbff) {
+						// surrogate pair
+						if (take_one(source, error) != '\\') {
+							error = "expected backslash";
+							return {};
+						}
+						if (take_one(source, error) != 'u') {
+							error = "expected u";
+							return {};
+						}
+						int32_t value2 = 0;
+						value2 |= take_hex() << 12;
+						value2 |= take_hex() << 8;
+						value2 |= take_hex() << 4;
+						value2 |= take_hex();
+						if (0xdc00 <= value2 && value2 <= 0xdfff) {
+							value = 0x10000 + ((value & 0x3ff) << 10) + (value2 & 0x3ff);
+						} else {
+							error = "invalid surrogate pair";
+							return {};
+						}
+					}
 					if (!error.empty()) return {};
 					encode_utf8(str, value);
 				} break;

src/value.hpp

@@ -221,11 +221,12 @@ void dump_impl_string(const std::string& str, std::string& result) {
 			case '"': result += "\\\""sv; break;
 			case '\\': result += "\\\\"sv; break;
 			default: {
-				// TODO: exceptionless dump to make alk happy
-				// in the meantime, this is better than creating
-				// an invalid json :+1:
-				if (c >= 0 && c < 0x20)
-					throw std::runtime_error("invalid string");
+				if (c >= 0 && c < 0x20) {
+					std::array<char, 7> buffer;
+					snprintf(buffer.data(), buffer.size(), "\\u%04x", c);
+					result += buffer.data();
+					break;
+				}
 				result.push_back(c); break;
 			}
 		}

test/test.cpp

@@ -260,12 +260,6 @@ TEST_CASE("Invalid json") {
 TEST_CASE("Invalid dump") {
     matjson::Value obj;
     using namespace std::string_literals;
-    // if this somehow happens (cough cough)
-    obj["Hello"] = "Wor\x00ld"s;
-    // then dump() should throw because it would create an invalid json
-    REQUIRE_THROWS(obj.dump());
-
-    obj.as_object().clear();
     // no throw
     obj.dump();
 
@@ -311,4 +305,28 @@ TEST_CASE("Rvalue as_array() return") {
     // `auto& arr = get_json().as_array();` should fail to compile, however i can't test that
     auto const& arr = get_json().as_array();
     REQUIRE(arr.size() == 4);
+}
+
+TEST_CASE("Parsing unicode characters") {
+    auto obj = matjson::parse(R"(
+        {
+            "hello": "\u00D3l\u00E1!",
+            "cool": "😎",
+            "pair": "\uD83D\uDE00"
+        }
+    )");
+
+    REQUIRE(obj["hello"].as_string() == "Ólá!");
+    REQUIRE(obj["cool"].as_string() == "😎");
+    REQUIRE(obj["pair"].as_string() == "😀");
+}
+
+TEST_CASE("Special characters") {
+    auto obj = matjson::parse(R"(
+        {
+            "control": "\b\f\n\r\t\u0012 "
+        }
+    )");
+
+    REQUIRE(obj["control"].as_string() == "\b\f\n\r\t\x12 ");
 }