From 3c0fbdd9d0c1f7d6367754237ca4b9662e76a86b Mon Sep 17 00:00:00 2001
From: Casey Rodarmor <casey@rodarmor.com>
Date: Sun, 13 Sep 2026 13:32:17 -0700
Subject: [PATCH 1/2] Reject uppercase hashes when deserializing

---
 src/hash.rs     | 26 +-------------------------
 src/language.rs |  8 +-------
 src/lib.rs      |  2 +-
 3 files changed, 3 insertions(+), 33 deletions(-)

diff --git a/src/hash.rs b/src/hash.rs
index 36d0f2a8..984108c5 100644
--- a/src/hash.rs
+++ b/src/hash.rs
@@ -1,6 +1,6 @@
 use super::*;
 
-#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
+#[derive(Clone, Copy, Debug, DeserializeFromStr, Eq, Hash, PartialEq, SerializeDisplay)]
 pub struct Hash(blake3::Hash);
 
 impl Hash {
@@ -65,30 +65,6 @@ impl PartialOrd for Hash {
   }
 }
 
-impl Serialize for Hash {
-  fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
-  where
-    S: Serializer,
-  {
-    self.0.to_string().serialize(serializer)
-  }
-}
-
-impl<'de> Deserialize<'de> for Hash {
-  fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
-  where
-    D: Deserializer<'de>,
-  {
-    use serde::de::{Error, Unexpected};
-
-    let s = String::deserialize(deserializer)?;
-
-    Ok(Self(s.parse::<blake3::Hash>().map_err(|_| {
-      D::Error::invalid_value(Unexpected::Str(&s), &"64 hex digits")
-    })?))
-  }
-}
-
 impl Display for Hash {
   fn fmt(&self, f: &mut Formatter) -> fmt::Result {
     Display::fmt(&self.0, f)
diff --git a/src/language.rs b/src/language.rs
index 0256ab98..0f258168 100644
--- a/src/language.rs
+++ b/src/language.rs
@@ -190,7 +190,7 @@ pub(crate) static CODES: LazyLock<BTreeMap<&'static str, &'static str>> = LazyLo
   .into()
 });
 
-#[derive(Clone, Copy, Debug, DeserializeFromStr, PartialEq)]
+#[derive(Clone, Copy, Debug, DeserializeFromStr, PartialEq, SerializeDisplay)]
 pub(crate) struct Language(&'static str);
 
 impl Language {
@@ -216,12 +216,6 @@ impl FromStr for Language {
   }
 }
 
-impl Serialize for Language {
-  fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
-    serializer.serialize_str(self.0)
-  }
-}
-
 impl Decode for Language {
   fn decode(decoder: &mut Decoder) -> Result<Self, DecodeError> {
     decoder.text()?.parse().context(decode_error::Language)
diff --git a/src/lib.rs b/src/lib.rs
index 72ea25df..ad6575fd 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -178,7 +178,7 @@ use {
   num_traits::One,
   owo_colors::Styled,
   regex::Regex,
-  serde::{Deserialize, Deserializer, Serialize, Serializer},
+  serde::{Deserialize, Serialize, Serializer},
   serde_with::{
     DeserializeFromStr, MapPreventDuplicates, SerializeDisplay, SetPreventDuplicates, serde_as,
     skip_serializing_none,

From 39e2000a9def9cf434383a655c9d390e537efa95 Mon Sep 17 00:00:00 2001
From: Casey Rodarmor <casey@rodarmor.com>
Date: Sun, 13 Sep 2026 13:34:45 -0700
Subject: [PATCH 2/2] Revise

---
 src/hash.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/hash.rs b/src/hash.rs
index 984108c5..34f50bf3 100644
--- a/src/hash.rs
+++ b/src/hash.rs
@@ -127,7 +127,7 @@ mod tests {
       serde_json::from_str::<Hash>("\"foo\"")
         .unwrap_err()
         .to_string(),
-      r#"invalid value: string "foo", expected 64 hex digits"#,
+      "expected 64 hex bytes, received 3 at line 1 column 5",
     );
   }