fix: multi indices search serialization (#841)

* fix: multi indices search serialization

* fix: dotnet format

* feat: flag `MultipleQueries` as Obsolete.

* fix: dotnet format

src/Algolia.Search.Test/EndToEnd/Client/MultipleOperationsTest.cs

@@ -130,6 +130,156 @@ public async Task TestMultipleOperations()
             Assert.That(multiQueri2.Results.ElementAt(0).Hits, Has.Exactly(2).Items);
             Assert.That(multiQueri2.Results.ElementAt(1).Hits, Is.Empty);
         }
+
+        [Test]
+        public async Task TestMultipleOperationsUsingQueryMultiIndices()
+        {
+            var objectsToSave = new List<BatchOperation<MultipleOperationClass>>
+            {
+                new BatchOperation<MultipleOperationClass>
+                {
+                    IndexName = _indexName1,
+                    Action = BatchActionType.AddObject,
+                    Body = new MultipleOperationClass { Firstname = "Jimmie" }
+                },
+                new BatchOperation<MultipleOperationClass>
+                {
+                    IndexName = _indexName1,
+                    Action = BatchActionType.AddObject,
+                    Body = new MultipleOperationClass { Firstname = "Jimmie" }
+                },
+                new BatchOperation<MultipleOperationClass>
+                {
+                    IndexName = _indexName2,
+                    Action = BatchActionType.AddObject,
+                    Body = new MultipleOperationClass { Firstname = "Jimmie" }
+                },
+                new BatchOperation<MultipleOperationClass>
+                {
+                    IndexName = _indexName2,
+                    Action = BatchActionType.AddObject,
+                    Body = new MultipleOperationClass { Firstname = "Jimmie" }
+                }
+            };
+
+            var saveMultiple = await BaseTest.SearchClient.MultipleBatchAsync(objectsToSave);
+            saveMultiple.Wait();
+
+            var objectsToRetrieve = new List<MultipleGetObject>
+            {
+                new MultipleGetObject { IndexName = _indexName1, ObjectID = saveMultiple.ObjectIDs.ElementAt(0) },
+                new MultipleGetObject { IndexName = _indexName1, ObjectID = saveMultiple.ObjectIDs.ElementAt(1) },
+                new MultipleGetObject { IndexName = _indexName2, ObjectID = saveMultiple.ObjectIDs.ElementAt(2) },
+                new MultipleGetObject { IndexName = _indexName2, ObjectID = saveMultiple.ObjectIDs.ElementAt(3) }
+            };
+
+            var multipleGet =
+                await BaseTest.SearchClient.MultipleGetObjectsAsync<MultipleOperationClass>(objectsToRetrieve);
+            Assert.That(multipleGet.Results, Has.Exactly(4).Items);
+            Assert.True(multipleGet.Results.All(x => x.Firstname.Equals("Jimmie")));
+
+            for (int i = 0; i < 4; i++)
+            {
+                Assert.True(multipleGet.Results.ElementAt(i).ObjectID == saveMultiple.ObjectIDs.ElementAt(i));
+            }
+
+            List<QueryMultiIndices> multipleSearch = new List<QueryMultiIndices>
+            {
+                new(_indexName1){HitsPerPage = 2 },
+                new(_indexName2){HitsPerPage = 2 },
+            };
+
+            MultipleQueriesRequest request = new MultipleQueriesRequest
+            {
+                Strategy = StrategyType.None,
+                Requests = multipleSearch
+            };
+
+            MultipleQueriesRequest request2 = new MultipleQueriesRequest
+            {
+                Strategy = StrategyType.StopIfEnoughMatches,
+                Requests = multipleSearch
+            };
+
+            var multiQueri = await BaseTest.SearchClient.MultipleQueriesAsync<MultipleOperationClass>(request);
+            var multiQueri2 = await BaseTest.SearchClient.MultipleQueriesAsync<MultipleOperationClass>(request2);
+
+            Assert.That(multiQueri.Results, Has.Exactly(2).Items);
+            Assert.That(multiQueri.Results.ElementAt(0).Hits, Has.Exactly(2).Items);
+            Assert.That(multiQueri.Results.ElementAt(1).Hits, Has.Exactly(2).Items);
+
+            Assert.That(multiQueri2.Results, Has.Exactly(2).Items);
+            Assert.That(multiQueri2.Results.ElementAt(0).Hits, Has.Exactly(2).Items);
+            Assert.That(multiQueri2.Results.ElementAt(1).Hits, Is.Empty);
+        }
+
+        [Test]
+        public async Task TestMultipleQueriesWithQueryMultiIndicesObject()
+        {
+            var objectsToSave = new List<BatchOperation<MultipleOperationClass>>
+            {
+                new BatchOperation<MultipleOperationClass>
+                {
+                    IndexName = _indexName3,
+                    Action = BatchActionType.AddObject,
+                    Body = new MultipleOperationClass { Firstname = "Jimmie" }
+                },
+            };
+
+            var saveMultiple = await BaseTest.SearchClient.MultipleBatchAsync(objectsToSave);
+            saveMultiple.Wait();
+
+            var query = new Query()
+            {
+                Explain = new List<string> { "test1", "test2" },
+                AroundPrecision = new List<AroundPrecision>
+                {
+                    new(){From = 0, Value = 1},
+                    new(){From = 100, Value = 10}
+                },
+                CustomParameters = new Dictionary<string, object>()
+                {
+                    {"hitsPerPage", 10}
+                },
+                TagFilters = new List<IEnumerable<string>>()
+                {
+                    new List<string>{ "one", "two"},
+                    new List<string>{ "one-two", "two-two"}
+                }
+            };
+
+            var request = new MultipleQueriesRequest
+            {
+                Requests = new List<QueryMultiIndices>{
+                    new QueryMultiIndices(_indexName3)
+                    {
+                        Explain = new List<string>{"test1", "test2"},
+                        AroundPrecision = new List<AroundPrecision>
+                        {
+                            new(){From = 0, Value = 1},
+                            new(){From = 100, Value = 10}
+                        },
+                        CustomParameters = new Dictionary<string, object>()
+                        {
+                            {"hitsPerPage", 10}
+                        },
+                        TagFilters = new List<IEnumerable<string>>()
+                        {
+                            new List<string>{ "one", "two"},
+                            new List<string>{ "one-two", "two-two"}
+                        }
+                    }
+                }
+            };
+
+            var index = BaseTest.SearchClient.InitIndex(_indexName3);
+
+            var responseSearch = index.Search<MultipleOperationClass>(query);
+            var responseMultipleQueries = BaseTest.SearchClient.MultipleQueries<MultipleOperationClass>(request);
+
+            Assert.AreEqual(responseSearch.Params, responseMultipleQueries.Results.First().Params);
+        }
+
         [Test]
         public async Task TestMultipleQueriesFacet()
         {

src/Algolia.Search/Models/Common/MultipleQueriesRequest.cs

@@ -21,6 +21,7 @@
 * THE SOFTWARE.
 */
 
+using System;
 using System.Collections.Generic;
 using Algolia.Search.Models.Search;
 using Algolia.Search.Serializer;
@@ -36,18 +37,24 @@ public class MultipleQueriesRequest
         /// <summary>
         /// List of requests
         /// </summary>
-        public IEnumerable<MultipleQueries> Requests { get; set; }
+        public IEnumerable<IMultipleQueries> Requests { get; set; }
 
         /// <summary>
         /// Request strategy <see cref="Enums.StrategyType"/>
         /// </summary>
         public string Strategy { get; set; }
     }
 
+    /// <summary>
+    /// Multiple queries interface
+    /// </summary>
+    public interface IMultipleQueries { }
+
     /// <summary>
     /// Multiple queries
     /// </summary>
-    public class MultipleQueries
+    [Obsolete("The recommended approach is to use a list of `QueryMultiIndices`.")]
+    public class MultipleQueries : IMultipleQueries
     {
         /// <summary>
         /// The name of the index to perform the operation

src/Algolia.Search/Models/Search/QueryMultiIndices.cs

@@ -0,0 +1,27 @@
+using Algolia.Search.Models.Common;
+
+namespace Algolia.Search.Models.Search
+{
+    /// <summary>
+    /// For more information regarding the parameters
+    /// https://www.algolia.com/doc/api-reference/search-api-parameters/
+    /// </summary>
+    public class QueryMultiIndices : Query, IMultipleQueries
+    {
+        /// <summary>
+        /// Create a new query with an empty search query, for a dedicated indice,
+        /// </summary>
+        /// <param name="indexName"></param>
+        /// <param name="searchQuery"></param>
+        public QueryMultiIndices(string indexName, string searchQuery = null)
+        {
+            IndexName = indexName;
+            SearchQuery = searchQuery;
+        }
+
+        /// <summary>
+        /// The name of the index to perform the operation
+        /// </summary>
+        public string IndexName { get; set; }
+    }
+}