removed dependency on query realization from EntityResourceService

Author: shuebner-zeiss

src/JsonApiDotNetCore/Data/DefaultEntityRepository.cs

@@ -157,5 +157,20 @@ public virtual async Task<IEnumerable<TEntity>> PageAsync(IQueryable<TEntity> en
                     .Take(numberOfElementsInPage)
                     .ToListAsync();
         }
+
+        public async Task<int> CountAsync(IQueryable<TEntity> entities)
+        {
+            return await entities.CountAsync();
+        }
+
+        public Task<TEntity> FirstOrDefaultAsync(IQueryable<TEntity> entities)
+        {
+            return entities.FirstOrDefaultAsync();
+        }
+
+        public async Task<IReadOnlyList<TEntity>> ToListAsync(IQueryable<TEntity> entities)
+        {
+            return await entities.ToListAsync();
+        }
     }
 }

src/JsonApiDotNetCore/Data/IEntityReadRepository.cs

@@ -27,5 +27,11 @@ public interface IEntityReadRepository<TEntity, in TId>
         Task<TEntity> GetAsync(TId id);
 
         Task<TEntity> GetAndIncludeAsync(TId id, string relationshipName);
+
+        Task<int> CountAsync(IQueryable<TEntity> entities);
+
+        Task<TEntity> FirstOrDefaultAsync(IQueryable<TEntity> entities);
+
+        Task<IReadOnlyList<TEntity>> ToListAsync(IQueryable<TEntity> entities);
     }
 }

src/JsonApiDotNetCore/Services/EntityResourceService.cs

@@ -5,7 +5,6 @@
 using JsonApiDotNetCore.Extensions;
 using JsonApiDotNetCore.Internal;
 using JsonApiDotNetCore.Models;
-using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.Logging;
 
 namespace JsonApiDotNetCore.Services
@@ -50,7 +49,7 @@ public virtual async Task<IEnumerable<T>> GetAsync()
                 entities = IncludeRelationships(entities, _jsonApiContext.QuerySet.IncludedRelationships);
 
             if (_jsonApiContext.Options.IncludeTotalRecordCount)
-                _jsonApiContext.PageManager.TotalRecords = await entities.CountAsync();
+                _jsonApiContext.PageManager.TotalRecords = await _entities.CountAsync(entities);
 
             // pagination should be done last since it will execute the query
             var pagedEntities = await ApplyPageQueryAsync(entities);
@@ -72,12 +71,12 @@ private bool ShouldIncludeRelationships()
 
         private async Task<T> GetWithRelationshipsAsync(TId id)
         {
-            var query = _entities.Get();
+            var query = _entities.Get().Where(e => e.Id.Equals(id));
             _jsonApiContext.QuerySet.IncludedRelationships.ForEach(r =>
             {
                 query = _entities.Include(query, r);
             });
-            return await query.FirstOrDefaultAsync(e => e.Id.Equals(id));
+            return await _entities.FirstOrDefaultAsync(query);
         }
 
         public virtual async Task<object> GetRelationshipsAsync(TId id, string relationshipName)