add optional defmt support for error types

add defmt as an optional dependent package

Author: avlec

Cargo.toml

@@ -23,6 +23,11 @@ optional = true
 default-features = false
 version = "1.0.100"
 
+[dependencies.defmt]
+version = "0.3.0"
+default-features = false
+optional = true
+
 [dev-dependencies]
 serde_derive = "1.0.100"
 

src/de/mod.rs

@@ -19,6 +19,7 @@ pub type Result<T> = core::result::Result<T, Error>;
 /// This type represents all possible errors that can occur when deserializing JSON data
 #[derive(Debug, PartialEq, Eq, Clone)]
 #[cfg_attr(not(feature = "custom-error-messages"), derive(Copy))]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
 #[non_exhaustive]
 pub enum Error {
     /// EOF while parsing a list.

src/ser/mod.rs

@@ -22,6 +22,7 @@ pub type Result<T> = ::core::result::Result<T, Error>;
 
 /// This type represents all possible errors that can occur when serializing JSON data
 #[derive(Debug, PartialEq, Eq, Copy, Clone)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
 #[non_exhaustive]
 pub enum Error {
     /// Buffer is full