Handle INDEXEMPTY and INDEXMISSING in FT.INFO response (#356)

* issue #351 - handle INDEXEMPTY and INDEXMISSING in FT.INFO response properly

* should work with enterprise and cluster but not with olders without INDEXMISSING support

* test run against 7.3 and later

Author: atakavci

src/NRedisStack/Search/DataTypes/InfoResult.cs

@@ -1,14 +1,20 @@
-using StackExchange.Redis;
+using System.Reflection.Emit;
+using StackExchange.Redis;
 
 namespace NRedisStack.Search.DataTypes;
 
 public class InfoResult
 {
     private readonly Dictionary<string, RedisResult> _all = new();
-    private static readonly string[] booleanAttributes = { "SORTABLE", "UNF", "NOSTEM", "NOINDEX", "CASESENSITIVE", "WITHSUFFIXTRIE" };
+    private Dictionary<string, RedisResult>[] _attributes;
+    private Dictionary<string, RedisResult> _indexOption;
+    private Dictionary<string, RedisResult> _gcStats;
+    private Dictionary<string, RedisResult> _cursorStats;
+
+    private static readonly string[] booleanAttributes = { "SORTABLE", "UNF", "NOSTEM", "NOINDEX", "CASESENSITIVE", "WITHSUFFIXTRIE", "INDEXEMPTY", "INDEXMISSING" };
     public string IndexName => GetString("index_name")!;
-    public Dictionary<string, RedisResult> IndexOption => GetRedisResultDictionary("index_options")!;
-    public Dictionary<string, RedisResult>[] Attributes => GetRedisResultDictionaryArray("attributes")!;
+    public Dictionary<string, RedisResult> IndexOption => _indexOption = _indexOption ?? GetRedisResultDictionary("index_options")!;
+    public Dictionary<string, RedisResult>[] Attributes => _attributes = _attributes ?? GetAttributesAsDictionaryArray()!;
     public long NumDocs => GetLong("num_docs");
     public string MaxDocId => GetString("max_doc_id")!;
     public long NumTerms => GetLong("num_terms");
@@ -48,9 +54,9 @@ public class InfoResult
     public long NumberOfUses => GetLong("number_of_uses");
 
 
-    public Dictionary<string, RedisResult> GcStats => GetRedisResultDictionary("gc_stats")!;
+    public Dictionary<string, RedisResult> GcStats => _gcStats = _gcStats ?? GetRedisResultDictionary("gc_stats")!;
 
-    public Dictionary<string, RedisResult> CursorStats => GetRedisResultDictionary("cursor_stats")!;
+    public Dictionary<string, RedisResult> CursorStats => _cursorStats = _cursorStats ?? GetRedisResultDictionary("cursor_stats")!;
 
     public InfoResult(RedisResult result)
     {
@@ -94,24 +100,29 @@ private double GetDouble(string key)
         return result;
     }
 
-    private Dictionary<string, RedisResult>[]? GetRedisResultDictionaryArray(string key)
+    private Dictionary<string, RedisResult>[]? GetAttributesAsDictionaryArray()
     {
-        if (!_all.TryGetValue(key, out var value)) return default;
+        if (!_all.TryGetValue("attributes", out var value)) return default;
         var values = (RedisResult[])value!;
         var result = new Dictionary<string, RedisResult>[values.Length];
         for (int i = 0; i < values.Length; i++)
         {
-            var fv = (RedisResult[])values[i]!;
             var dict = new Dictionary<string, RedisResult>();
-            for (int j = 0; j < fv.Length; j += 2)
+
+            IEnumerable<RedisResult> enumerable = (RedisResult[])values[i]!;
+            IEnumerator<RedisResult> results = enumerable.GetEnumerator();
+            while (results.MoveNext())
             {
-                if (booleanAttributes.Contains((string)fv[j]!))
+                string attribute = (string)results.Current;
+                // if its boolean attributes add itself to the dictionary and continue
+                if (booleanAttributes.Contains(attribute))
                 {
-                    dict.Add((string)fv[j]!, fv[j--]);
+                    dict.Add(attribute, results.Current);
                 }
                 else
-                {
-                    dict.Add((string)fv[j]!, fv[j + 1]);
+                {//if its not a boolean attribute, add the next item as value to the dictionary
+                    results.MoveNext(); ;
+                    dict.Add(attribute, results.Current);
                 }
             }
             result[i] = dict;

tests/NRedisStack.Tests/Search/SearchTests.cs

@@ -887,6 +887,40 @@ public void AlterAddSortable()
         Assert.Equal(4, info.CursorStats.Count);
     }
 
+    [SkipIfRedis(Comparison.LessThan, "7.3.0")]
+    public void InfoWithIndexEmptyAndIndexMissing()
+    {
+        IDatabase db = redisFixture.Redis.GetDatabase();
+        db.Execute("FLUSHALL");
+        var ft = db.FT(2);
+        var vectorAttrs = new Dictionary<string, object>()
+        {
+            ["TYPE"] = "FLOAT32",
+            ["DIM"] = "2",
+            ["DISTANCE_METRIC"] = "L2",
+        };
+
+        Schema sc = new Schema()
+           .AddTextField("text1", 1.0, emptyIndex: true, missingIndex: true)
+           .AddTagField("tag1", emptyIndex: true, missingIndex: true)
+           .AddNumericField("numeric1", missingIndex: true)
+           .AddGeoField("geo1", missingIndex: true)
+           .AddGeoShapeField("geoshape1", Schema.GeoShapeField.CoordinateSystem.FLAT, missingIndex: true)
+           .AddVectorField("vector1", Schema.VectorField.VectorAlgo.FLAT, vectorAttrs, missingIndex: true);
+        Assert.True(ft.Create(index, FTCreateParams.CreateParams(), sc));
+
+        var info = ft.Info(index);
+        var attributes = info.Attributes;
+        foreach (var attribute in attributes)
+        {
+            Assert.True(attribute.ContainsKey("INDEXMISSING"));
+            if (attribute["attribute"].ToString() == "text1" || attribute["attribute"].ToString() == "tag1")
+            {
+                Assert.True(attribute.ContainsKey("INDEXEMPTY"));
+            }
+        }
+    }
+
     [SkipIfRedis(Is.OSSCluster, Is.Enterprise)]
     public async Task AlterAddSortableAsync()
     {