clean up

fix/src/nar.rs

@@ -0,0 +1,66 @@
+use std::io::Read;
+use std::path::Path;
+
+use nix_nar::Encoder;
+use sha2::{Digest, Sha256};
+
+use crate::error::{Error, Result};
+
+pub fn compute_nar_hash(path: &Path) -> Result<[u8; 32]> {
+    let mut hasher = Sha256::new();
+    std::io::copy(
+        &mut Encoder::new(path).map_err(|err| Error::internal(err.to_string()))?,
+        &mut hasher,
+    )
+    .map_err(|err| Error::internal(err.to_string()))?;
+    Ok(hasher.finalize().into())
+}
+
+pub fn pack_nar(path: &Path) -> Result<Vec<u8>> {
+    let mut buffer = Vec::new();
+    Encoder::new(path)
+        .map_err(|err| Error::internal(err.to_string()))?
+        .read_to_end(&mut buffer)
+        .map_err(|err| Error::internal(err.to_string()))?;
+    Ok(buffer)
+}
+
+#[cfg(test)]
+#[allow(clippy::unwrap_used)]
+mod tests {
+    use std::fs;
+
+    use tempfile::TempDir;
+
+    use super::*;
+
+    #[test_log::test]
+    fn test_simple_file() {
+        let temp = TempDir::new().unwrap();
+        let file_path = temp.path().join("test.txt");
+        fs::write(&file_path, "hello").unwrap();
+
+        let hash = hex::encode(compute_nar_hash(&file_path).unwrap());
+        assert_eq!(
+            hash,
+            "0a430879c266f8b57f4092a0f935cf3facd48bbccde5760d4748ca405171e969"
+        );
+        assert!(!hash.is_empty());
+        assert_eq!(hash.len(), 64);
+    }
+
+    #[test_log::test]
+    fn test_directory() {
+        let temp = TempDir::new().unwrap();
+        fs::write(temp.path().join("a.txt"), "aaa").unwrap();
+        fs::write(temp.path().join("b.txt"), "bbb").unwrap();
+
+        let hash = hex::encode(compute_nar_hash(temp.path()).unwrap());
+        assert_eq!(
+            hash,
+            "0036c14209749bc9b9631e2077b108b701c322ab53853cd26f2746268a86fc0f"
+        );
+        assert!(!hash.is_empty());
+        assert_eq!(hash.len(), 64);
+    }
+}