Add internal IsTrained API in service of testing

src/Couchbase.Lite.Shared/API/Database/Collection.cs

@@ -953,6 +953,8 @@ private void Save(Document doc, C4Document** outDoc, C4Document* baseDoc, bool d
 
  #region Internal Methods
 
+ internal bool IsIndexTrained(string name) => LiteCoreBridge.Check(err => Native.c4coll_isIndexTrained(c4coll, name, err));
+
  /// <summary>
  /// Returns false if this collection has been deleted, or its database closed.
  /// </summary>

src/LiteCore/binding_list/c4.def

@@ -37,6 +37,7 @@ c4coll_getDocExpiration
 c4coll_createIndex
 c4coll_deleteIndex
 c4coll_getIndexesInfo
+c4coll_isIndexTrained
 
 c4db_copyNamed
 c4db_deleteNamed

src/LiteCore/src/LiteCore.Shared/Interop/C4Index_native.cs

@@ -0,0 +1,48 @@
+//
+// C4Index_native.cs
+//
+// Copyright (c) 2024 Couchbase, Inc All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http:https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+using System;
+using System.Linq;
+using System.Runtime.InteropServices;
+
+using LiteCore.Util;
+
+namespace LiteCore.Interop
+{
+
+ internal unsafe static partial class Native
+ {
+ public static bool c4coll_isIndexTrained(C4Collection* collection, string? name, C4Error* outError)
+ {
+ using(var name_ = new C4String(name)) {
+ return NativeRaw.c4coll_isIndexTrained(collection, name_.AsFLSlice(), outError);
+ }
+ }
+
+
+ }
+
+ internal unsafe static partial class NativeRaw
+ {
+ [DllImport(Constants.DllName, CallingConvention = CallingConvention.Cdecl)]
+ [return: MarshalAs(UnmanagedType.U1)]
+ public static extern bool c4coll_isIndexTrained(C4Collection* collection, FLSlice name, C4Error* outError);
+
+
+ }
+}

src/LiteCore/src/LiteCore.Shared/LiteCore.Shared.projitems

@@ -33,6 +33,7 @@
  <Compile Include="$(MSBuildThisFileDirectory)Interop\C4Error_defs.cs" />
  <Compile Include="$(MSBuildThisFileDirectory)Interop\C4Error_native.cs" />
  <Compile Include="$(MSBuildThisFileDirectory)Interop\C4IndexTypes_defs.cs" />
+ <Compile Include="$(MSBuildThisFileDirectory)Interop\C4Index_native.cs" />
  <Compile Include="$(MSBuildThisFileDirectory)Interop\C4Listener.cs" />
  <Compile Include="$(MSBuildThisFileDirectory)Interop\C4ListenerTypes_defs.cs" />
  <Compile Include="$(MSBuildThisFileDirectory)Interop\C4Listener_native.cs" />