Added tests for char tools

Test/String__Upper.cpp

@@ -0,0 +1,72 @@
+#include <StringTools.h>
+#include "Catch2.h"
+
+// Tests that uppering an empty string returns an empty string
+TEST_CASE(__FILE__"/EmptyString", "[Strings][Upper]")
+{
+    // Setup
+    const std::string in = "";
+
+    // Exercise
+    const std::string out = StringTools::Upper(in);
+
+    // Verify
+    REQUIRE(out == "");
+    return;
+}
+
+// Tests that uppering a string without any letters returns itself
+TEST_CASE(__FILE__"/Symbols", "[Strings][Upper]")
+{
+    // Setup
+    const std::string in = "66! _-\n*";
+
+    // Exercise
+    const std::string out = StringTools::Upper(in);
+
+    // Verify
+    REQUIRE(out == "66! _-\n*");
+    return;
+}
+
+// Tests that uppering a string of uppercase letters returns itself
+TEST_CASE(__FILE__"/AlreadyUppered", "[Strings][Upper]")
+{
+    // Setup
+    const std::string in = "UGHAREYOUSERIOUS";
+
+    // Exercise
+    const std::string out = StringTools::Upper(in);
+
+    // Verify
+    REQUIRE(out == "UGHAREYOUSERIOUS");
+    return;
+}
+
+// Tests that uppering a string of lowercase letters returns the uppercase version
+TEST_CASE(__FILE__"/Lowercase", "[Strings][Upper]")
+{
+    // Setup
+    const std::string in = "ughareyouserious";
+
+    // Exercise
+    const std::string out = StringTools::Upper(in);
+
+    // Verify
+    REQUIRE(out == "UGHAREYOUSERIOUS");
+    return;
+}
+
+// Tests that uppering a string of uppercase, lowercase letters and symbols returns the uppercase version
+TEST_CASE(__FILE__"/Mixed", "[Strings][Upper]")
+{
+    // Setup
+    const std::string in = "Ugh, Are You Serious?! DON'T do that!!!";
+
+    // Exercise
+    const std::string out = StringTools::Upper(in);
+
+    // Verify
+    REQUIRE(out == "UGH, ARE YOU SERIOUS?! DON'T DO THAT!!!");
+    return;
+}