Use defmt's public interface.

src/defmt.rs

@@ -12,7 +12,7 @@ where
     T: defmt::Format,
 {
     fn format(&self, fmt: Formatter<'_>) {
-        fmt.inner.fmt_slice(self.as_slice())
+        defmt::write!(fmt, "{=[?]}", self.as_slice())
     }
 }
 
@@ -22,7 +22,7 @@ where
     u8: defmt::Format,
 {
     fn format(&self, fmt: Formatter<'_>) {
-        fmt.inner.str(self.as_str());
+        defmt::write!(fmt, "{=str}", self.as_str());
     }
 }
 
@@ -41,7 +41,8 @@ mod tests {
     }
 
     #[test]
-    /// Tests encoding Vec with defmt,
+    /// Tests encoding Vec with defmt, asserting these types may be serialized
+    /// Note: the exact wire format is NOT checked since its an unstable implementation detail of an external crate.
     /// based on https://github.com/knurling-rs/defmt/blob/697a8e807bd766a80ada2d57514a9da1232dbc9a/tests/encode.rs#L523
     fn test_defmt_format_vec() {
         let val: Vec<_, U8> = Vec::from_slice(b"abc").unwrap();
@@ -51,21 +52,10 @@ mod tests {
         let g = defmt::Formatter{inner: &mut f};
         val.format(g);
         f.finalize();
-        assert_eq!(
-            f.bytes(),
-            &[
-                index,
-                val.len().try_into().unwrap(),
-                inc(index, 1),
-                // Data bytes.
-                97u8,
-                98u8,
-                99u8,
-            ]
-        );
     }
 
-    /// Tests encoding String with defmt,
+    /// Tests encoding String with defmt, asserting these types may be serialized
+    /// Note: the exact wire format is NOT checked since its an unstable implementation detail of an external crate.
     /// based loosely on https://github.com/knurling-rs/defmt/blob/main/tests/encode.rs#L483
     #[test]
     fn test_defmt_format_str() {
@@ -74,20 +64,8 @@ mod tests {
         let index = defmt::export::fetch_string_index();
 
         let mut f = defmt::InternalFormatter::new();
-        let g = defmt::Formatter{inner: &mut f};
+        let g = defmt::Formatter { inner: &mut f };
         val.format(g);
         f.finalize();
-        assert_eq!(
-            f.bytes(),
-            &[
-                index,
-                val.len().try_into().unwrap(),
-                inc(index, 1),
-                // Data bytes.
-                102u8,
-                111u8,
-                111u8,
-            ]
-        );
     }
 }