Add tests of version encoder and decoder

diff --git a/primitives/src/block.rs b/primitives/src/block.rs
index a2d46ce1..9eda5364 100644
--- a/primitives/src/block.rs
+++ b/primitives/src/block.rs
@@ -934,6 +934,8 @@ mod tests {
     #[cfg(all(feature = "alloc", feature = "hex"))]
     use core::str::FromStr as _;
 
+    use encoding::{Decoder, Encoder};
+
     use super::*;
 
     fn dummy_header() -> Header {
@@ -1498,4 +1500,41 @@ mod tests {
         assert_eq!(block.check_witness_commitment(), (false, None));
         assert!(matches!(block.validate(), Err(InvalidBlockError::InvalidWitnessCommitment)));
     }
+
+    #[test]
+    fn version_encoder_emits_consensus_bytes() {
+        let version = Version::from_consensus(123_456_789);
+        let mut encoder = version.encoder();
+
+        assert_eq!(encoder.current_chunk(), &version.to_consensus().to_le_bytes());
+        assert!(!encoder.advance());
+    }
+
+    #[test]
+    fn version_decoder_end_and_read_limit() {
+        let mut decoder = VersionDecoder::new();
+        let bytes_arr = Version::TWO.to_consensus().to_le_bytes();
+        let mut bytes = bytes_arr.as_slice();
+
+        assert!(decoder.read_limit() > 0);
+
+        let needs_more = decoder.push_bytes(&mut bytes).unwrap();
+        assert!(!needs_more);
+        assert!(bytes.is_empty());
+
+        assert_eq!(decoder.read_limit(), 0);
+        let decoded = decoder.end().unwrap();
+        assert_eq!(decoded, Version::TWO);
+    }
+
+    #[test]
+    fn version_decoder_default_roundtrip() {
+        let version = Version::from_consensus(123_456_789);
+        let mut decoder = VersionDecoder::default();
+        let consensus = version.to_consensus().to_le_bytes();
+        let mut bytes = consensus.as_slice();
+        decoder.push_bytes(&mut bytes).unwrap();
+
+        assert_eq!(decoder.end().unwrap(), version);
+    }
 }