[FEEDS-1132]return ranking expression with score vars (#170)

* chore: return ranking expression with score vars

* chore: fix test

Author: itsmeadi

src/Models/GenericResponse.cs

@@ -1,3 +1,4 @@
+using Newtonsoft.Json;
 using System.Collections.Generic;
 
 namespace Stream.Models
@@ -7,6 +8,10 @@ public class GenericGetResponse<T> : ResponseBase
     {
         /// <summary>Container for <typeparamref name="T"/> objects.</summary>
         public List<T> Results { get; set; }
+
+        /// <summary>The ranking expression used for scoring activities.</summary>
+        [JsonProperty("ranking_expr")]
+        public string RankingExpression { get; set; }
     }
 
     /// <summary>Base class for personalized read responses of <typeparamref name="T"/>.</summary>

src/Models/GetOptions.cs

@@ -20,6 +20,7 @@ public class GetOptions
         private string _user_id = null;
         private string _ranking_vars = null;
         private bool _score_vars = false;
+        private bool _ranking_expr = false;
         private string _discard_actors = null;
         private string _discard_actors_sep = null;
         private string _moderation_template = null;
@@ -68,6 +69,12 @@ public GetOptions WithScoreVars()
             return this;
         }
 
+        public GetOptions WithRankingExpr()
+        {
+            _ranking_expr = true;
+            return this;
+        }
+
         public GetOptions WithRankingVars(IDictionary<string, object> rankingVars)
         {
             _ranking_vars = StreamJsonConverter.SerializeObject(rankingVars);
@@ -149,6 +156,9 @@ internal void Apply(RestRequest request)
             if (_score_vars)
                 request.AddQueryParameter("withScoreVars", "true");
 
+            if (_ranking_expr)
+                request.AddQueryParameter("with_ranking_expr", "true");
+
             if (!string.IsNullOrWhiteSpace(_discard_actors_sep))
                 request.AddQueryParameter("discard_actors_sep", _discard_actors_sep);
 

tests/ActivityTests/GetActivityTests.cs

@@ -172,6 +172,36 @@ public async Task TestScoreVars()
             Assert.IsNull(r2.Results[0].ScoreVars);
         }
 
+        [Test]
+        public async Task TestRankingExpression()
+        {
+            var feed = this.RankedFeed;
+
+            var newActivity1 = new Activity("1", "test", "1")
+            {
+                ForeignId = "r-test-1",
+                Time = DateTime.Parse("2000-08-16T16:32:32"),
+            };
+
+            newActivity1.SetData("popularity", 123);
+            var r1 = await feed.AddActivityAsync(newActivity1);
+
+            // Test with ranking expression flag
+            var r2 = await feed.GetFlatActivitiesAsync(GetOptions.Default.WithLimit(1).WithRanking("popularity").WithRankingExpr());
+            Assert.IsNotNull(r2.RankingExpression);
+            Assert.IsNotEmpty(r2.RankingExpression);
+
+            // Test without ranking expression flag
+            r2 = await feed.GetFlatActivitiesAsync(GetOptions.Default.WithLimit(1).WithRanking("popularity"));
+            Assert.IsNull(r2.RankingExpression);
+
+            // Test with both score vars and ranking expression
+            r2 = await feed.GetFlatActivitiesAsync(GetOptions.Default.WithLimit(1).WithRanking("popularity").WithScoreVars().WithRankingExpr());
+            Assert.IsNotNull(r2.RankingExpression);
+            Assert.IsNotEmpty(r2.RankingExpression);
+            Assert.IsNotNull(r2.Results[0].ScoreVars);
+        }
+
         [Test]
         public async Task TestGetActivitiesByForeignIDAndTime()
         {

tests/TestBase.cs

@@ -22,7 +22,7 @@ public void Setup()
             FlatFeed = Client.Feed("flat", System.Guid.NewGuid().ToString());
             AggregateFeed = Client.Feed("aggregate", System.Guid.NewGuid().ToString());
             NotificationFeed = Client.Feed("notification", System.Guid.NewGuid().ToString());
-            RankedFeed = Client.Feed("ranked", System.Guid.NewGuid().ToString());
+            RankedFeed = Client.Feed("user", System.Guid.NewGuid().ToString());
         }
     }
 }