Use raw json value

Author: simolus3

crates/core/src/sync/interface.rs

@@ -12,13 +12,13 @@ use crate::sync::storage_adapter::StorageAdapter;
 use crate::sync::subscriptions::{StreamKey, apply_subscriptions};
 use alloc::borrow::Cow;
 use alloc::boxed::Box;
-use alloc::collections::btree_map::BTreeMap;
 use alloc::rc::Rc;
 use alloc::{string::String, vec::Vec};
 use powersync_sqlite_nostd::bindings::SQLITE_RESULT_SUBTYPE;
 use powersync_sqlite_nostd::{self as sqlite, ColumnType};
 use powersync_sqlite_nostd::{Connection, Context};
 use serde::{Deserialize, Serialize};
+use serde_json::value::RawValue;
 use sqlite::{ResultCode, Value};
 
 use crate::sync::BucketPriority;
@@ -41,19 +41,8 @@ pub struct StartSyncStream {
     /// We will increase the expiry date for those streams at the time we connect and disconnect.
     #[serde(default)]
     pub active_streams: Rc<Vec<StreamKey>>,
-    /// Application metadata to include in the request when opening a sync stream.
-    ///
-    /// This should only contain a JSON map of strings.
-    ///
-    /// We use `BTreeMap<String, String>` instead of `serde_json::Map<String, serde_json::Value>`
-    /// (like `parameters` uses) because:
-    /// 1. It enforces type safety at compile time - values must be strings, not arbitrary JSON
-    /// 2. It requires no runtime validation to ensure values are strings
-    /// 3. It serializes to the same JSON format (a map with string values)
-    /// 4. `serde_json::Map<String, String>` doesn't implement `Serialize`/`Deserialize` - the
-    ///    `serde_json::Map` type only supports `serde_json::Value` as the value type, not `String`
     #[serde(default)]
-    pub app_metadata: Option<BTreeMap<String, String>>,
+    pub app_metadata: Option<Box<RawValue>>,
 }
 
 impl StartSyncStream {
@@ -175,7 +164,7 @@ pub struct StreamingSyncRequest {
     pub parameters: Option<serde_json::Map<String, serde_json::Value>>,
     pub streams: Rc<StreamSubscriptionRequest>,
     #[serde(skip_serializing_if = "Option::is_none")]
-    pub app_metadata: Option<BTreeMap<String, String>>,
+    pub app_metadata: Option<Box<RawValue>>,
 }
 
 #[derive(Debug, Serialize, PartialEq)]