fix(versioned): Track values as JSON

Tracked values were stored as serde_yaml::Value, which represents enum
variants as YAML tags. After a roundtrip through the JSON status, these could
not be deserialized again, which panicked during the upgrade. The status is
stored as JSON anyway, so values are now tracked as serde_json::Value.

Also fix restoring type changes whose downgraded value is null: it is
serialized as `downgradedValue: null` and deserialized as None, so the
comparison never matched. A missing downgraded value is now treated as null.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

Author: sbernauer

Cargo.lock

@@ -306,7 +306,7 @@ impl VersionedField {
             Direction::Downgrade => {
                 let next_change = changes.get_expect(&next_version.inner);
 
-                let serde_yaml_path = &*mod_gen_ctx.crates.serde_yaml;
+                let serde_json_path = &*mod_gen_ctx.crates.serde_json;
                 let versioned_path = &*mod_gen_ctx.crates.versioned;
 
                 match next_change {
@@ -318,7 +318,7 @@ impl VersionedField {
                         Some(quote! {
                             upgrades.push(#versioned_path::ChangedValue {
                                 json_path: #json_path_ident,
-                                value: #serde_yaml_path::to_value(&#from_struct_ident.#ident).unwrap(),
+                                value: #serde_json_path::to_value(&#from_struct_ident.#ident).unwrap(),
                                 downgraded_value: ::core::option::Option::None,
                             });
                         })
@@ -351,7 +351,7 @@ impl VersionedField {
                 to_ident,
                 ..
             } if next_change.is_type_change() => {
-                let serde_yaml_path = &*mod_gen_ctx.crates.serde_yaml;
+                let serde_json_path = &*mod_gen_ctx.crates.serde_json;
                 let value_ident = to_ident.tracked_value_ident();
 
                 let field_ident = match direction {
@@ -360,7 +360,7 @@ impl VersionedField {
                 };
 
                 Some(quote! {
-                    let #value_ident = #serde_yaml_path::to_value(&#from_struct_ident.#field_ident).unwrap();
+                    let #value_ident = #serde_json_path::to_value(&#from_struct_ident.#field_ident).unwrap();
                 })
             }
             _ => None,
@@ -383,7 +383,7 @@ impl VersionedField {
             Direction::Downgrade => {
                 let next_change = changes.get_expect(&next_version.inner);
 
-                let serde_yaml_path = &*mod_gen_ctx.crates.serde_yaml;
+                let serde_json_path = &*mod_gen_ctx.crates.serde_json;
                 let versioned_path = &*mod_gen_ctx.crates.versioned;
 
                 match next_change {
@@ -400,7 +400,7 @@ impl VersionedField {
                                 json_path: #json_path_ident,
                                 value: #value_ident,
                                 downgraded_value: ::core::option::Option::Some(
-                                    #serde_yaml_path::to_value(&spec.#from_ident).unwrap()
+                                    #serde_json_path::to_value(&spec.#from_ident).unwrap()
                                 ),
                             });
                         })
@@ -426,29 +426,32 @@ impl VersionedField {
         match direction {
             Direction::Upgrade => {
                 let next_change = changes.get_expect(&next_version.inner);
-                let serde_yaml_path = &*mod_gen_ctx.crates.serde_yaml;
+                let serde_json_path = &*mod_gen_ctx.crates.serde_json;
 
                 match next_change {
                     ItemStatus::Addition { ident, .. } => {
                         let json_path_ident = ident.json_path_ident();
 
                         Some(quote! {
                             json_path if json_path == #json_path_ident => {
-                                spec.#ident = #serde_yaml_path::from_value(value).unwrap();
+                                spec.#ident = #serde_json_path::from_value(value).unwrap();
                             },
                         })
                     }
                     // The tracked value is only applied if the field still contains the value it
                     // was downgraded to. Otherwise, a user changed the field in the older version
                     // and that change takes precedence over the tracked value.
+                    //
+                    // A downgraded value of null is serialized as `downgradedValue: null`, which is
+                    // deserialized as None. As such, a missing downgraded value is treated as null.
                     ItemStatus::Change { to_ident, .. } if next_change.is_type_change() => {
                         let json_path_ident = to_ident.json_path_ident();
                         let value_ident = to_ident.tracked_value_ident();
 
                         Some(quote! {
                             json_path if json_path == #json_path_ident => {
-                                if downgraded_value.as_ref() == ::core::option::Option::Some(&#value_ident) {
-                                    spec.#to_ident = #serde_yaml_path::from_value(value).unwrap();
+                                if downgraded_value.unwrap_or_default() == #value_ident {
+                                    spec.#to_ident = #serde_json_path::from_value(value).unwrap();
                                 }
                             },
                         })

crates/stackable-versioned-macros/src/codegen/item/field.rs

@@ -25,7 +25,9 @@ All notable changes to this project will be documented in this file.
 ### Fixed
 
 - Fix `From` impls of enum variants with multiple unnamed fields ([#YYYY]).
-- Use the configured `serde_yaml` crate path when applying tracked values ([#ZZZZ]).
+- BREAKING: Store tracked values as `serde_json::Value` instead of `serde_yaml::Value`. Tracked
+  enum values were serialized as YAML tags, which failed to deserialize after a roundtrip through
+  the JSON status ([#ZZZZ]).
 
 [#1284]: https://github.com/stackabletech/operator-rs/pull/1284
 [#1285]: https://github.com/stackabletech/operator-rs/pull/1285

crates/stackable-versioned-macros/tests/snapshots/stackable_versioned_macros__snapshots__pass@conversion_tracking.rs.snap

@@ -17,7 +17,6 @@ kube.workspace = true
 schemars.workspace = true
 serde.workspace = true
 serde_json.workspace = true
-serde_yaml.workspace = true
 snafu.workspace = true
 
 [dev-dependencies]

crates/stackable-versioned-macros/tests/snapshots/stackable_versioned_macros__snapshots__pass@conversion_tracking_enum.rs.snap

@@ -113,8 +113,11 @@ pub struct ChangedValue {
     pub json_path: String,
 
     /// The value to be used when upgrading or downgrading the custom resource.
+    // NOTE: This needs to be a JSON value, because the status is stored as JSON. YAML values
+    // represent enum variants as tags, which can't be deserialized again after a roundtrip
+    // through JSON.
     #[schemars(schema_with = "raw_object_schema")]
-    pub value: serde_yaml::Value,
+    pub value: serde_json::Value,
 
     /// The value the field was converted to during the downgrade. Only set for fields which
     /// changed their type.
@@ -124,7 +127,7 @@ pub struct ChangedValue {
     /// kept instead.
     #[serde(default, skip_serializing_if = "Option::is_none")]
     #[schemars(schema_with = "raw_object_schema")]
-    pub downgraded_value: Option<serde_yaml::Value>,
+    pub downgraded_value: Option<serde_json::Value>,
 }
 
 // TODO (@Techassi): Think about where this should live. Basically this already exists in