From 1d8c03132fca75b30e78dcf59aa10dbe6015655e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Imobach=20Gonz=C3=A1lez=20Sosa?= <igonzalezsosa@suse.com>
Date: Wed, 17 Dec 2025 23:42:33 +0000
Subject: [PATCH] Merge the storage config

---
 rust/agama-utils/src/api/storage/config.rs | 74 +++++++++++++++++++++-
 1 file changed, 71 insertions(+), 3 deletions(-)

diff --git a/rust/agama-utils/src/api/storage/config.rs b/rust/agama-utils/src/api/storage/config.rs
index 3a3719ccaa..6b0dc96a7e 100644
--- a/rust/agama-utils/src/api/storage/config.rs
+++ b/rust/agama-utils/src/api/storage/config.rs
@@ -22,14 +22,12 @@ use merge::Merge;
 use serde::{Deserialize, Serialize};
 use serde_json::Value;
 
-#[derive(Clone, Debug, Default, Serialize, Deserialize, Merge, utoipa::ToSchema)]
+#[derive(Clone, Debug, Default, Serialize, Deserialize, utoipa::ToSchema)]
 #[serde(rename_all = "camelCase")]
 pub struct Config {
     #[serde(skip_serializing_if = "Option::is_none")]
-    #[merge(strategy = merge::option::overwrite_none)]
     pub storage: Option<Value>,
     #[serde(skip_serializing_if = "Option::is_none")]
-    #[merge(strategy = merge::option::overwrite_none)]
     pub legacy_autoyast_storage: Option<Value>,
 }
 
@@ -38,3 +36,73 @@ impl Config {
         self.storage.is_some() || self.legacy_autoyast_storage.is_some()
     }
 }
+
+impl Merge for Config {
+    fn merge(&mut self, other: Self) {
+        if let Some(storage) = &mut self.storage {
+            if let Some(other_storage) = other.storage {
+                merge_values_as_objects(storage, other_storage);
+            }
+        } else {
+            self.storage = other.storage;
+        }
+
+        // No need to merge both values because it is just an array of drives.
+        if self.legacy_autoyast_storage.is_none() {
+            self.legacy_autoyast_storage = other.legacy_autoyast_storage;
+        }
+    }
+}
+
+// Merge to serde_json::Value structs.
+//
+// Both Value structs are supposed to represent JSON objects.
+fn merge_values_as_objects(left: &mut Value, right: Value) {
+    let Value::Object(left_object) = left else {
+        return;
+    };
+
+    let Value::Object(right_object) = right else {
+        return;
+    };
+
+    for (k, v) in right_object {
+        left_object.entry(k).or_insert(v);
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use merge::Merge;
+
+    use super::*;
+
+    #[test]
+    fn test_merge_with_default_config() {
+        let mut config: Config = serde_json::from_str(r#"{ "storage": { "drives": [] }}"#).unwrap();
+        let original = Config::default();
+
+        config.merge(original);
+        assert!(config.storage.is_some());
+    }
+
+    #[test]
+    fn test_merge_storage_key() {
+        let mut config: Config = serde_json::from_str(r#"{ "storage": { "drives": [] }}"#).unwrap();
+        let original: Config = serde_json::from_str(r#"{ "storage": { "mdRaids": [] }}"#).unwrap();
+
+        config.merge(original);
+        let value = config.storage.unwrap();
+        assert!(value.get("drives").is_some());
+        assert!(value.get("mdRaids").is_some());
+    }
+
+    #[test]
+    fn test_merge_with_no_storage() {
+        let mut config = Config::default();
+        let original: Config = serde_json::from_str(r#"{ "storage": { "drives": [] }}"#).unwrap();
+
+        config.merge(original);
+        assert!(config.storage.is_some());
+    }
+}