Add test code for String operator +

Author: giulcioffi

test/CMakeLists.txt

@@ -43,6 +43,7 @@ set(TEST_SRCS
   src/Ringbuffer/test_read_char.cpp
   src/Ringbuffer/test_store_char.cpp
   src/String/test_concat.cpp
+  src/String/test_operators.cpp
   src/String/test_compareTo.cpp
   src/String/test_comparisonFunc.cpp
   src/String/test_characterAccessFunc.cpp

test/src/String/test_operators.cpp

@@ -0,0 +1,102 @@
+/*
+ * Copyright (c) 2020 Arduino.  All rights reserved.
+ */
+
+/**************************************************************************************
+ * INCLUDE
+ **************************************************************************************/
+
+#include <catch.hpp>
+
+#include <String.h>
+
+/**************************************************************************************
+ * TEST CODE
+ **************************************************************************************/
+
+TEST_CASE ("Testing String::operator + (const StringSumHelper, const String)", "[String-operator+-01]")
+{
+  arduino::String str1("Hello ");
+  arduino::String str2("Arduino");
+  arduino::String str("Hello Arduino");
+  REQUIRE(str.compareTo(str1+str2) == 0);
+}
+
+TEST_CASE ("Testing String::operator + (const StringSumHelper, const char *)", "[String-operator+-02]")
+{
+  arduino::String str1("Hello ");
+  arduino::String str("Hello Arduino");
+  REQUIRE(str.compareTo(str1+"Arduino") == 0);
+}
+
+TEST_CASE ("Testing String::operator + (const StringSumHelper, char)", "[String-operator+-03]")
+{
+  arduino::String str1("Hello");
+  char ch='!';
+  arduino::String str("Hello!");
+  REQUIRE(str.compareTo(str1+ch) == 0);
+}
+
+TEST_CASE ("Testing String::operator + (const StringSumHelper, unsigned char)", "[String-operator+-04]")
+{
+  arduino::String str1("Hello ");
+  unsigned char ch='A';
+  arduino::String str("Hello 65"); /* ASCII['A'] = 65 */
+  REQUIRE(str.compareTo(str1+ch) == 0);
+}
+
+TEST_CASE ("Testing String::operator + (const StringSumHelper, int)", "[String-operator+-05]")
+{
+  arduino::String str1("Hello ");
+  arduino::String str("Hello 1");
+  REQUIRE(str.compareTo(str1+1) == 0);
+}
+
+TEST_CASE ("Testing String::operator + (unsigned int)", "[String-operator+-06]")
+{
+  arduino::String str1("Hello ");
+  unsigned int const num = 1;
+  arduino::String str("Hello 1");
+  REQUIRE(str.compareTo(str1+num) == 0);
+}
+
+TEST_CASE ("Testing String::operator + (long)", "[String-operator+-07]")
+{
+  arduino::String str1("Hello ");
+  long const num = -1;
+  arduino::String str("Hello -1");
+  REQUIRE(str.compareTo(str1+num) == 0);
+}
+
+TEST_CASE ("Testing String::operator + (unsigned long)", "[String-operator+-08]")
+{
+  arduino::String str1("Hello ");
+  unsigned long const num = 1;
+  arduino::String str("Hello 1");
+  REQUIRE(str.compareTo(str1+num) == 0);
+}
+
+TEST_CASE ("Testing String::operator + (float)", "[String-operator+-09]")
+{
+  arduino::String str1("Hello ");
+  float const num = 1.234f;
+  arduino::String str("Hello 1.23");
+  REQUIRE(str.compareTo(str1+num) == 0);
+}
+
+TEST_CASE ("Testing String::operator + (double)", "[String-operator+-10]")
+{
+  arduino::String str1("Hello ");
+  double const num = 5.678;
+  arduino::String str("Hello 5.68");
+  REQUIRE(str.compareTo(str1+num) == 0);
+}
+
+TEST_CASE ("Testing String::operator + (const __FlashStringHelper *)", "[String-operator+-11]")
+{
+#undef F
+#define F(string_literal) (reinterpret_cast<const arduino::__FlashStringHelper *>(PSTR(string_literal)))
+  arduino::String str1("Hello ");
+  arduino::String str("Hello Arduino");
+  REQUIRE(str.compareTo(str1+F("Arduino")) == 0);
+}