Add a test

src/parser/deserializer.rs

@@ -467,3 +467,27 @@ impl<'a, 'de: 'a> de::SeqAccess<'de> for StructDeserializer<'a, 'de> {
         return Some(self.fields.len());
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::any::type_name;
+    #[test]
+    fn check_type_name_properties() {
+        // This ensures that certain properties for the
+        // std::any::type_name function hold, that
+        // this code relies on. The type_name docs explicitly
+        // mention that the actual format of the output
+        // is unspecified and change is likely.
+        // This test makes sure that such change is detected
+        // by this test failing, and not things silently breaking.
+        // Specifically, we rely on this behaviour further above
+        // in the file to special case Tagged<Value> parsing.
+        let tuple = type_name::<()>();
+        let tagged_tuple = type_name::<Tagged<()>>();
+        let tagged_value = type_name::<Tagged<Value>>();
+        assert!(tuple != tagged_tuple);
+        assert!(tuple != tagged_value);
+        assert!(tagged_tuple != tagged_value);
+    }
+}