From 930c805127cada70e4e4ab03c7680214b5c2a4f5 Mon Sep 17 00:00:00 2001
From: Andrew Hickman <andrew.hickman1@sky.com>
Date: Wed, 8 Feb 2023 14:09:29 +0000
Subject: [PATCH] fix: MetadataKey::from_bytes returns an error (#1246)

BREAKING: `Metadata::from_bytes` returns an error now
---
 tonic/src/metadata/key.rs | 29 ++++++++++++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/tonic/src/metadata/key.rs b/tonic/src/metadata/key.rs
index a5a1248..e40660d 100644
--- a/tonic/src/metadata/key.rs
+++ b/tonic/src/metadata/key.rs
@@ -42,7 +42,7 @@ impl<VE: ValueEncoding> MetadataKey<VE> {
         match HeaderName::from_bytes(src) {
             Ok(name) => {
                 if !VE::is_valid_key(name.as_str()) {
-                    panic!("invalid metadata key")
+                    return Err(InvalidMetadataKey::new());
                 }
 
                 Ok(MetadataKey {
@@ -282,3 +282,30 @@ impl Default for InvalidMetadataKey {
 }
 
 impl Error for InvalidMetadataKey {}
+
+#[cfg(test)]
+mod tests {
+    use super::{AsciiMetadataKey, BinaryMetadataKey};
+
+    #[test]
+    fn test_from_bytes_binary() {
+        assert!(BinaryMetadataKey::from_bytes(b"").is_err());
+        assert!(BinaryMetadataKey::from_bytes(b"\xFF").is_err());
+        assert!(BinaryMetadataKey::from_bytes(b"abc").is_err());
+        assert_eq!(
+            BinaryMetadataKey::from_bytes(b"abc-bin").unwrap().as_str(),
+            "abc-bin"
+        );
+    }
+
+    #[test]
+    fn test_from_bytes_ascii() {
+        assert!(AsciiMetadataKey::from_bytes(b"").is_err());
+        assert!(AsciiMetadataKey::from_bytes(b"\xFF").is_err());
+        assert_eq!(
+            AsciiMetadataKey::from_bytes(b"abc").unwrap().as_str(),
+            "abc"
+        );
+        assert!(AsciiMetadataKey::from_bytes(b"abc-bin").is_err());
+    }
+}