fix: use explicit snake_case serialization for CompressionType

Per project convention, enum string representations should use
snake_case. Use explicit strum serialize attributes instead of
serialize_all to avoid incorrect splitting of acronyms like
GZip → g_zip and ZStd → z_std.

src/compression_engine/mod.rs

@@ -34,11 +34,17 @@ use crate::compression_engine::program::CompressionEngineProgram;
 #[derive(Debug, Eq, PartialEq, Clone, EnumIter, Display, EnumString, enum_map::Enum)]
 #[strum(ascii_case_insensitive)]
 pub enum CompressionType {
+    #[strum(serialize = "lz4")]
     LZ4,
+    #[strum(serialize = "gzip")]
     GZip,
+    #[strum(serialize = "bzip2")]
     BZip2,
+    #[strum(serialize = "xz")]
     XZ,
+    #[strum(serialize = "zstd")]
     ZStd,
+    #[strum(serialize = "none")]
     None,
 }
 

src/tests/compression_types/conversion_tests.rs

@@ -5,9 +5,9 @@ mod tests {
 
     #[test]
     fn test_compression_type_display() {
-        assert_eq!(format!("{}", CompressionType::LZ4), "LZ4");
-        assert_eq!(format!("{}", CompressionType::GZip), "GZip");
-        assert_eq!(format!("{}", CompressionType::None), "None");
+        assert_eq!(format!("{}", CompressionType::LZ4), "lz4");
+        assert_eq!(format!("{}", CompressionType::GZip), "gzip");
+        assert_eq!(format!("{}", CompressionType::None), "none");
     }
 
     #[test]