fixing issue with multiple where predicates paired with a select (#493)

Author: slorello89

src/Redis.OM/Common/ExpressionTranslator.cs

@@ -229,7 +229,7 @@ internal static RedisQuery BuildQueryFromExpression(Expression expression, Type
                                 query.GeoFilter = ExpressionParserUtilities.TranslateGeoFilter(exp);
                                 break;
                             case "Where":
-                                query.QueryText = TranslateWhereMethod(exp, parameters);
+                                query.QueryText = query.QueryText == "*" ? TranslateWhereMethod(exp, parameters) : $"({TranslateWhereMethod(exp, parameters)} {query.QueryText})";
                                 break;
                             case "NearestNeighbors":
                                 query.NearestNeighbors = ParseNearestNeighborsFromExpression(exp);

test/Redis.OM.Unit.Tests/RediSearchTests/SearchTests.cs

@@ -3325,6 +3325,26 @@ public void TestSelectWithWhere()
                 "Name");
         }
 
+        [Fact]
+        public void TestSelectWithMultipleWheres()
+        {
+            _substitute.ClearSubstitute();
+            _substitute.Execute(Arg.Any<string>(), Arg.Any<object[]>()).Returns(_mockReply);
+            IRedisCollection<Person> collection = new RedisCollection<Person>(_substitute);
+            collection = collection.Where(x => x.Name == "Steve");
+            _ = collection.Where(x => x.Age == 33).Select(x => x.Name).ToList();
+            _substitute.Received().Execute(
+                "FT.SEARCH",
+                "person-idx",
+                "((@Name:\"Steve\") (@Age:[33 33]))",
+                "LIMIT",
+                "0",
+                "100",
+                "RETURN",
+                "1",
+                "Name");
+        }
+
         [Fact]
         public void TestNullableEnumQueries()