Merge pull request CosmWasm#1201 from CosmWasm/debug-binary-as-hex

Change Debug implementation of Binary to hex

Author: webmaster128

CHANGELOG.md

@@ -6,6 +6,13 @@ and this project adheres to
 
 ## [Unreleased]
 
+### Changed
+
+- cosmwasm-std: The `Debug` implementation of `Binary` now produces a hex string
+  instead of a list of bytes ([#1199]).
+
+[#1199]: https://github.com/CosmWasm/cosmwasm/issues/1199
+
 ## [1.0.0-beta4] - 2021-12-23
 
 ### Changed

packages/std/src/binary.rs

@@ -10,7 +10,7 @@ use crate::errors::{StdError, StdResult};
 /// with serde. It also adds some helper methods to help encode inline.
 ///
 /// This is only needed as serde-json-{core,wasm} has a horrible encoding for Vec<u8>
-#[derive(Clone, Default, Debug, PartialEq, Eq, Hash, PartialOrd, Ord, JsonSchema)]
+#[derive(Clone, Default, PartialEq, Eq, Hash, PartialOrd, Ord, JsonSchema)]
 pub struct Binary(#[schemars(with = "String")] pub Vec<u8>);
 
 impl Binary {
@@ -75,6 +75,19 @@ impl fmt::Display for Binary {
     }
 }
 
+impl fmt::Debug for Binary {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        // Use an output inspired by tuples (https://doc.rust-lang.org/std/fmt/struct.Formatter.html#method.debug_tuple)
+        // but with a custom implementation to avoid the need for an intemediate hex string.
+        write!(f, "Binary(")?;
+        for byte in self.0.iter() {
+            write!(f, "{:02x}", byte)?;
+        }
+        write!(f, ")")?;
+        Ok(())
+    }
+}
+
 impl From<&[u8]> for Binary {
     fn from(binary: &[u8]) -> Self {
         Self(binary.to_vec())
@@ -438,6 +451,17 @@ mod tests {
         assert!(res.is_err());
     }
 
+    #[test]
+    fn binary_implements_debug() {
+        // Some data
+        let binary = Binary(vec![0x07, 0x35, 0xAA, 0xcb, 0x00, 0xff]);
+        assert_eq!(format!("{:?}", binary), "Binary(0735aacb00ff)",);
+
+        // Empty
+        let binary = Binary(vec![]);
+        assert_eq!(format!("{:?}", binary), "Binary()",);
+    }
+
     #[test]
     fn binary_implements_deref() {
         // Dereference to [u8]

packages/vm/src/checksum.rs

@@ -18,7 +18,9 @@ impl Checksum {
         Checksum(Sha256::digest(wasm).into())
     }
 
-    /// Creates a lowercase hex encoded copy of this checksum
+    /// Creates a lowercase hex encoded copy of this checksum.
+    ///
+    /// This takes an owned `self` instead of a reference because `Checksum` is cheap to `Copy`.
     pub fn to_hex(self) -> String {
         self.to_string()
     }