prost: clarify encoding test buffer copying

tokio-rs · Apr 2, 2024 · ea5ae54 · ea5ae54
1 parent 1ac740e
commit ea5ae54
Showing 1 changed file with 15 additions and 7 deletions.
diff --git a/src/encoding.rs b/src/encoding.rs
@@ -1616,10 +1616,14 @@ mod test {
 
             assert_eq!(encoded_len_varint(value), encoded.len());
 
-            let roundtrip_value = decode_varint(&mut &*encoded).expect("decoding failed");
+            // See: https://github.com/tokio-rs/prost/pull/1008 for copying reasoning.
+            let mut encoded_copy = encoded;
+            let roundtrip_value = decode_varint(&mut encoded_copy).expect("decoding failed");
             assert_eq!(value, roundtrip_value);
 
-            let roundtrip_value = decode_varint_slow(&mut &*encoded).expect("slow decoding failed");
+            let mut encoded_copy = encoded;
+            let roundtrip_value =
+                decode_varint_slow(&mut encoded_copy).expect("slow decoding failed");
             assert_eq!(value, roundtrip_value);
         }
 
@@ -1678,14 +1682,18 @@ mod test {
         );
     }
 
+    const U64_MAX_PLUS_ONE: &[u8] = &[0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x02];
+
     #[test]
     fn varint_overflow() {
-        let mut u64_max_plus_one: &[u8] =
-            &[0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x02];
+        let mut copy = U64_MAX_PLUS_ONE;
+        decode_varint(&mut copy).expect_err("decoding u64::MAX + 1 succeeded");
+    }
 
-        decode_varint(&mut u64_max_plus_one).expect_err("decoding u64::MAX + 1 succeeded");
-        decode_varint_slow(&mut u64_max_plus_one)
-            .expect_err("slow decoding u64::MAX + 1 succeeded");
+    #[test]
+    fn variant_slow_overflow() {
+        let mut copy = U64_MAX_PLUS_ONE;
+        decode_varint_slow(&mut copy).expect_err("slow decoding u64::MAX + 1 succeeded");
     }
 
     /// This big bowl o' macro soup generates an encoding property test for each combination of map