Fix ambiguous key deserialization (#197)

automerge-protocol/src/serde_impls/key.rs

@@ -1,20 +0,0 @@
-use std::str::FromStr;
-
-use serde::{Deserialize, Deserializer};
-use smol_str::SmolStr;
-
-use crate::{ElementId, Key};
-
-impl<'de> Deserialize<'de> for Key {
-    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
-    where
-        D: Deserializer<'de>,
-    {
-        let s = SmolStr::deserialize(deserializer)?;
-        if let Ok(eid) = ElementId::from_str(&s) {
-            Ok(Key::Seq(eid))
-        } else {
-            Ok(Key::Map(s))
-        }
-    }
-}

automerge-protocol/src/serde_impls/mod.rs

@@ -8,7 +8,6 @@ mod change_hash;
 mod cursor_diff;
 mod diff;
 mod element_id;
-mod key;
 mod multi_element_insert;
 mod object_id;
 mod op;

automerge-protocol/src/serde_impls/op.rs

@@ -158,8 +158,20 @@ impl<'de> Deserialize<'de> for Op {
                     match field.as_ref() {
                         "action" => read_field("action", &mut action, &mut map)?,
                         "obj" => read_field("obj", &mut obj, &mut map)?,
-                        "key" => read_field("key", &mut key, &mut map)?,
-                        "elemId" => read_field("elemId", &mut key, &mut map)?,
+                        "key" => {
+                            if key.is_some() {
+                                return Err(Error::duplicate_field("key"));
+                            } else {
+                                key = Some(Key::Map(map.next_value()?));
+                            }
+                        }
+                        "elemId" => {
+                            if key.is_some() {
+                                return Err(Error::duplicate_field("elemId"));
+                            } else {
+                                key = Some(Key::Seq(map.next_value()?))
+                            }
+                        }
                         "pred" => read_field("pred", &mut pred, &mut map)?,
                         "insert" => read_field("insert", &mut insert, &mut map)?,
                         "datatype" => read_field("datatype", &mut datatype, &mut map)?,