test: Add display length test

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "cbor4ii"
-version = "0.3.1"
+version = "0.3.2"
 authors = ["quininer <[email protected]>"]
 description = "CBOR: Concise Binary Object Representation"
 repository = "https://github.com/quininer/cbor4ii"
@@ -26,7 +26,7 @@ serde_bytes = "0.11"
 data-encoding = "2"
 serde_cbor = "0.11"
 ciborium = "0.2"
-criterion = "0.4"
+criterion = "0.5"
 
 [package.metadata.docs.rs]
 all-features = true

tests/serde.rs

@@ -479,3 +479,42 @@ fn test_regression_min_i64() {
  let min_i64: i64 = from_slice(&buf).unwrap();
  assert_eq!(min_i64, i64::MIN);
 }
+
+#[test]
+fn test_debug_ser_len() {
+ struct Test {
+ long: char,
+ short: char
+ }
+
+ impl fmt::Display for Test {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ let s = (0..257).map(|_| self.long).collect::<String>();
+ write!(f, "{}", s)?;
+
+ for _ in 0..257 {
+ write!(f, "{}", self.short)?;
+ }
+
+ Ok(())
+ }
+ }
+
+ impl Serialize for Test {
+ fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+ where
+ S: serde::Serializer,
+ {
+ serializer.collect_str(self)
+ }
+ }
+
+ let test = Test {
+ long: 'l',
+ short: 's'
+ };
+
+ let buf = to_vec(Vec::new(), &test).unwrap();
+ assert!(dbg!(buf.len()) < 777); // <= 0.3.1
+ assert!(dbg!(buf.len()) <= 523);
+}