tryCompress and tryDecompress returns std::optional<std::string> instead of just std::string

Author: w0lek

vpr/src/server/zlibutils.cpp

@@ -3,13 +3,13 @@
 #include <cstring> // Include cstring for memset
 #include <zlib.h>
 
-std::string tryCompress(const std::string& decompressed) 
+std::optional<std::string> tryCompress(const std::string& decompressed)
 {
     z_stream zs;
     memset(&zs, 0, sizeof(zs));
 
     if (deflateInit(&zs, Z_BEST_COMPRESSION) != Z_OK) {
-        return "";
+        return std::nullopt;
     }
 
     zs.next_in = reinterpret_cast<Bytef*>(const_cast<char*>(decompressed.data()));
@@ -35,19 +35,19 @@ std::string tryCompress(const std::string& decompressed)
     deflateEnd(&zs);
 
     if (retCode != Z_STREAM_END) {
-        return "";
+        return std::nullopt;
     }
 
     return result;
 }
 
-std::string tryDecompress(const std::string& compressed) 
+std::optional<std::string> tryDecompress(const std::string& compressed)
 {
     z_stream zs;
     memset(&zs, 0, sizeof(zs));
 
     if (inflateInit(&zs) != Z_OK) {
-        return "";
+        return std::nullopt;
     }
 
     zs.next_in = reinterpret_cast<Bytef*>(const_cast<char*>(compressed.data()));
@@ -74,7 +74,7 @@ std::string tryDecompress(const std::string& compressed)
     inflateEnd(&zs);
 
     if (retCode != Z_STREAM_END) {
-        return "";
+        return std::nullopt;
     }
 
     return result;

vpr/src/server/zlibutils.h

@@ -4,7 +4,7 @@
 #include <string>
 #include <optional>
 
-std::string tryCompress(const std::string& decompressed);
-std::string tryDecompress(const std::string& compressed);
+std::optional<std::string> tryCompress(const std::string& decompressed);
+std::optional<std::string> tryDecompress(const std::string& compressed);
 
 #endif /* ZLIBUTILS_H */

vpr/test/test_server_zlibutils.cpp

@@ -7,11 +7,14 @@ TEST_CASE("test_server_zlib_utils", "[vpr]")
 {
     const std::string orig{"This string is going to be compressed now"};
 
-    std::string compressed = tryCompress(orig);
-    std::string decompressed = tryDecompress(compressed);
+    std::optional<std::string> compressedOpt = tryCompress(orig);
+    REQUIRE(compressedOpt);
+    REQUIRE(orig != compressedOpt.value());
 
-    REQUIRE(orig != compressed);
-    REQUIRE(orig == decompressed);
+    std::optional<std::string> decompressedOpt = tryDecompress(compressedOpt.value());
+    REQUIRE(decompressedOpt);
+
+    REQUIRE(orig == decompressedOpt.value());
 }