matrix-sdk: Vary sync token with each EventBuilder::build_sync_response call.

This allows us to hold onto an EventBuilder object and use it to build
multiple sync responses. Previously this would have resulted in each
of the responses having the same next_batch sync token. This would make
clients ignore the latter responses if they have already received any of
the previous ones.

matrix_sdk_test/src/lib.rs

@@ -61,15 +61,22 @@ pub struct EventBuilder {
     ephemeral: Vec<Event>,
     /// The account data events that determine the state of a `Room`.
     account_data: Vec<Event>,
+    /// Internal counter to enable the `prev_batch` and `next_batch` of each sync response to vary.
+    batch_counter: i64,
 }
 
 impl EventBuilder {
+    pub fn new() -> Self {
+        let builder: EventBuilder = Default::default();
+        builder
+    }
+
     /// Add an event to the room events `Vec`.
     pub fn add_ephemeral<Ev: TryFromRaw>(
-        mut self,
+        &mut self,
         file: EventsFile,
         variant: fn(Ev) -> Event,
-    ) -> Self {
+    ) -> &mut Self {
         let val: &str = match file {
             EventsFile::Typing => include_str!("../test_data/events/typing.json"),
             _ => panic!("unknown ephemeral event file {:?}", file),
@@ -86,10 +93,10 @@ impl EventBuilder {
     /// Add an event to the room events `Vec`.
     #[allow(clippy::match_single_binding, unused)]
     pub fn add_account<Ev: TryFromRaw>(
-        mut self,
+        &mut self,
         file: EventsFile,
         variant: fn(Ev) -> Event,
-    ) -> Self {
+    ) -> &mut Self {
         let val: &str = match file {
             _ => panic!("unknown account event file {:?}", file),
         };
@@ -104,10 +111,10 @@ impl EventBuilder {
 
     /// Add an event to the room events `Vec`.
     pub fn add_room_event<Ev: TryFromRaw>(
-        mut self,
+        &mut self,
         file: EventsFile,
         variant: fn(Ev) -> RoomEvent,
-    ) -> Self {
+    ) -> &mut Self {
         let val = match file {
             EventsFile::Member => include_str!("../test_data/events/member.json"),
             EventsFile::PowerLevels => include_str!("../test_data/events/power_levels.json"),
@@ -126,11 +133,11 @@ impl EventBuilder {
     }
 
     pub fn add_custom_joined_event<Ev: TryFromRaw>(
-        mut self,
+        &mut self,
         room_id: &RoomId,
         event: serde_json::Value,
         variant: fn(Ev) -> RoomEvent,
-    ) -> Self {
+    ) -> &mut Self {
         let event = serde_json::from_value::<EventJson<Ev>>(event)
             .unwrap()
             .deserialize()
@@ -147,11 +154,11 @@ impl EventBuilder {
     }
 
     pub fn add_custom_invited_event<Ev: TryFromRaw>(
-        mut self,
+        &mut self,
         room_id: &RoomId,
         event: serde_json::Value,
         variant: fn(Ev) -> AnyStrippedStateEvent,
-    ) -> Self {
+    ) -> &mut Self {
         let event = serde_json::from_value::<EventJson<Ev>>(event)
             .unwrap()
             .deserialize()
@@ -164,11 +171,11 @@ impl EventBuilder {
     }
 
     pub fn add_custom_left_event<Ev: TryFromRaw>(
-        mut self,
+        &mut self,
         room_id: &RoomId,
         event: serde_json::Value,
         variant: fn(Ev) -> RoomEvent,
-    ) -> Self {
+    ) -> &mut Self {
         let event = serde_json::from_value::<EventJson<Ev>>(event)
             .unwrap()
             .deserialize()
@@ -182,10 +189,10 @@ impl EventBuilder {
 
     /// Add a state event to the state events `Vec`.
     pub fn add_state_event<Ev: TryFromRaw>(
-        mut self,
+        &mut self,
         file: EventsFile,
         variant: fn(Ev) -> StateEvent,
-    ) -> Self {
+    ) -> &mut Self {
         let val = match file {
             EventsFile::Alias => include_str!("../test_data/events/alias.json"),
             EventsFile::Aliases => include_str!("../test_data/events/aliases.json"),
@@ -202,7 +209,7 @@ impl EventBuilder {
     }
 
     /// Add an presence event to the presence events `Vec`.
-    pub fn add_presence_event(mut self, file: EventsFile) -> Self {
+    pub fn add_presence_event(&mut self, file: EventsFile) -> &mut Self {
         let val = match file {
             EventsFile::Presence => include_str!("../test_data/events/presence.json"),
             _ => panic!("unknown presence event file {:?}", file),
@@ -217,9 +224,14 @@ impl EventBuilder {
     }
 
     /// Consumes `ResponseBuilder` and returns `SyncResponse`.
-    pub fn build_sync_response(mut self) -> SyncResponse {
+    pub fn build_sync_response(&mut self) -> SyncResponse {
         let main_room_id = RoomId::try_from("!SVkFJHzfwvuaIEawgC:localhost").unwrap();
 
+        // First time building a sync response, so initialize the `prev_batch` to a default one.
+        let prev_batch = self.generate_sync_token();
+        self.batch_counter += 1;
+        let next_batch = self.generate_sync_token();
+
         // TODO generalize this.
         let joined_room = serde_json::json!({
             "summary": {},
@@ -235,7 +247,7 @@ impl EventBuilder {
             "timeline": {
                 "events": self.joined_room_events.remove(&main_room_id).unwrap_or_default(),
                 "limited": true,
-                "prev_batch": "t392-516_47314_0_7_1_1_1_11444_1"
+                "prev_batch": prev_batch
             },
             "unread_notifications": {
                 "highlight_count": 0,
@@ -262,7 +274,7 @@ impl EventBuilder {
                 "timeline": {
                     "events": events,
                     "limited": true,
-                    "prev_batch": "t392-516_47314_0_7_1_1_1_11444_1"
+                    "prev_batch": prev_batch
                 },
                 "unread_notifications": {
                     "highlight_count": 0,
@@ -282,7 +294,7 @@ impl EventBuilder {
                 "timeline": {
                     "events": events,
                     "limited": false,
-                    "prev_batch": "t392-516_47314_0_7_1_1_1_11444_1"
+                    "prev_batch": prev_batch
                 },
             });
             left_rooms.insert(room_id, room);
@@ -302,7 +314,7 @@ impl EventBuilder {
         let body = serde_json::json! {
             {
                 "device_one_time_keys_count": {},
-                "next_batch": "s526_47314_0_7_1_1_1_11444_1",
+                "next_batch": next_batch,
                 "device_lists": {
                     "changed": [],
                     "left": []
@@ -325,6 +337,10 @@ impl EventBuilder {
             .unwrap();
         SyncResponse::try_from(response).unwrap()
     }
+
+    fn generate_sync_token(&self) -> String {
+        format!("t392-516_47314_0_7_1_1_1_11444_{}", self.batch_counter)
+    }
 }
 
 /// Embedded sync reponse files