obfs, tests: Modify string_obfs to string

test/impl/string.cpp

@@ -0,0 +1,43 @@
+#include <obfs/string.hpp>
+#include <catch2/catch.hpp>
+
+template <char Key>
+constexpr char enc_xor(char value) {
+    return value ^ Key;
+}
+
+template <char Key>
+constexpr char add(char c) {
+    return c + Key;
+}
+
+template <char(*f)(char), char(*g)(char)>
+constexpr char comp(char c) {
+    return f(g(c));
+}
+
+TEST_CASE("Single encoder, decoder", "[obfs::String]") {
+    REQUIRE(
+        obfs::make_string<enc_xor<0x50>, enc_xor<0x50>>("Hello World !").decode()
+        == std::string_view("Hello World !"));
+}
+
+TEST_CASE("Multiple encoder, decoder", "[obfs::String]") {
+    using table = obfs::make_table<
+        obfs::encoder_seq<enc_xor<0x50>, add<10>, comp<enc_xor<0x50>, add<10>>>,
+        obfs::decoder_seq<enc_xor<0x50>, add<-10>, comp<add<-10>, enc_xor<0x50>>>>;
+
+    MAKE_STRING(str, "Hello World !", table);
+    REQUIRE(str.decode() == std::string_view("Hello World !"));
+}
+
+TEST_CASE("Multiple encoder, decoder pair", "[obfs::String]") {
+    using table = obfs::make_pair_table<
+        obfs::encoder_pair<enc_xor<0x50>, enc_xor<0x50>>,
+        obfs::encoder_pair<add<10>, add<-10>>,
+        obfs::encoder_pair<comp<enc_xor<0x50>, add<10>>, comp<add<-10>, enc_xor<0x50>>>
+    >;
+
+    MAKE_STRING(str, "Hello World !", table);
+    REQUIRE(str.decode() == std::string_view("Hello World !"));
+}