Add missing test

extras/tests/TextFormatter/CMakeLists.txt

@@ -4,6 +4,7 @@
 
 add_executable(TextFormatterTests 
 	writeFloat.cpp
+	writeInteger.cpp
 	writeString.cpp
 )
 

extras/tests/TextFormatter/writeInteger.cpp

@@ -0,0 +1,55 @@
+// ArduinoJson - https://arduinojson.org
+// Copyright Benoit Blanchon 2014-2021
+// MIT License
+
+#include <catch.hpp>
+#include <limits>
+#include <string>
+
+#include <ArduinoJson/Json/TextFormatter.hpp>
+#include <ArduinoJson/Serialization/Writer.hpp>
+
+using namespace ARDUINOJSON_NAMESPACE;
+
+template <typename T>
+void checkWriteInteger(T value, std::string expected) {
+  char output[1024];
+  StaticStringWriter sb(output, sizeof(output));
+  TextFormatter<StaticStringWriter> writer(sb);
+  writer.writeInteger<T>(value);
+  REQUIRE(expected == output);
+  REQUIRE(writer.bytesWritten() == expected.size());
+}
+
+TEST_CASE("int8_t") {
+  checkWriteInteger<int8_t>(0, "0");
+  checkWriteInteger<int8_t>(-128, "-128");
+  checkWriteInteger<int8_t>(127, "127");
+}
+
+TEST_CASE("uint8_t") {
+  checkWriteInteger<uint8_t>(0, "0");
+  checkWriteInteger<uint8_t>(255, "255");
+}
+
+TEST_CASE("int16_t") {
+  checkWriteInteger<int16_t>(0, "0");
+  checkWriteInteger<int16_t>(-32768, "-32768");
+  checkWriteInteger<int16_t>(32767, "32767");
+}
+
+TEST_CASE("uint16_t") {
+  checkWriteInteger<uint16_t>(0, "0");
+  checkWriteInteger<uint16_t>(65535, "65535");
+}
+
+TEST_CASE("int32_t") {
+  checkWriteInteger<int32_t>(0, "0");
+  checkWriteInteger<int32_t>(-2147483647 - 1, "-2147483648");
+  checkWriteInteger<int32_t>(2147483647, "2147483647");
+}
+
+TEST_CASE("uint32_t") {
+  checkWriteInteger<uint32_t>(0, "0");
+  checkWriteInteger<uint32_t>(4294967295U, "4294967295");
+}

src/ArduinoJson/Json/TextFormatter.hpp

@@ -92,7 +92,6 @@ class TextFormatter {
     unsigned_type unsigned_value;
     if (value < 0) {
       writeRaw('-');
-      // TODO: check -128
       unsigned_value = static_cast<unsigned_type>(-value);
     } else {
       unsigned_value = static_cast<unsigned_type>(value);