wip: review feedback

src/lib.rs

@@ -523,23 +523,28 @@ impl DerInner<'_> {
 
 // Format an iterator of u8 into a hex string
 fn hex<'a>(f: &mut fmt::Formatter<'_>, payload: impl IntoIterator<Item = &'a u8>) -> fmt::Result {
-    for b in payload {
+    for (i, b) in payload.into_iter().enumerate() {
+        if i == 0 {
+            write!(f, "0x")?;
+        }
         write!(f, "{:02x}", b)?;
     }
     Ok(())
 }
 
 #[cfg(feature = "std")]
 mod tests {
+    use super::*;
+
     #[test]
     fn der_debug() {
-        let der = super::Der::from_slice(&[0x01, 0x02, 0x03]);
-        assert_eq!(format!("{:?}", der), "010203");
+        let der = Der::from_slice(&[0x01, 0x02, 0x03]);
+        assert_eq!(format!("{:?}", der), "0x010203");
     }
 
     #[test]
-    fn algid_debug() {
-        let algid = super::AlgorithmIdentifier::from_slice(&[0x01, 0x02, 0x03]);
-        assert_eq!(format!("{:?}", algid), "010203");
+    fn alg_id_debug() {
+        let alg_id = AlgorithmIdentifier::from_slice(&[0x01, 0x02, 0x03]);
+        assert_eq!(format!("{:?}", alg_id), "0x010203");
     }
 }