From ce9ed10f8aea71b6762bf52b748a6872600f86b0 Mon Sep 17 00:00:00 2001
From: Koen Bekkenutte <2912652+kbekkenutte@users.noreply.github.com>
Date: Fri, 4 Jun 2021 05:02:43 +0800
Subject: [PATCH] Proper code reuse

---
 .../Extensions/ExpressionExtensions.cs         | 18 ++++++++++++++++++
 .../Extensions/QueryableExtensions.cs          | 15 +++++++++++++++
 ...ustomQueryTranslationPreprocessorFactory.cs | 10 ++++------
 3 files changed, 37 insertions(+), 6 deletions(-)
 create mode 100644 src/EntityFrameworkCore.Projectables/Extensions/ExpressionExtensions.cs
 create mode 100644 src/EntityFrameworkCore.Projectables/Extensions/QueryableExtensions.cs

diff --git a/src/EntityFrameworkCore.Projectables/Extensions/ExpressionExtensions.cs b/src/EntityFrameworkCore.Projectables/Extensions/ExpressionExtensions.cs
new file mode 100644
index 0000000..c18048a
--- /dev/null
+++ b/src/EntityFrameworkCore.Projectables/Extensions/ExpressionExtensions.cs
@@ -0,0 +1,18 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Linq.Expressions;
+using System.Text;
+using System.Threading.Tasks;
+using EntityFrameworkCore.Projectables.Services;
+
+namespace EntityFrameworkCore.Projectables.Extensions
+{
+    public static class ExpressionExtensions
+    {
+        static ProjectableExpressionReplacer _projectableExpressionReplacer = new ProjectableExpressionReplacer(new ProjectionExpressionResolver());
+
+        public static Expression ExpandQuaryables(this Expression expression)
+            => _projectableExpressionReplacer.Visit(expression);
+    }
+}
diff --git a/src/EntityFrameworkCore.Projectables/Extensions/QueryableExtensions.cs b/src/EntityFrameworkCore.Projectables/Extensions/QueryableExtensions.cs
new file mode 100644
index 0000000..fb0a5d6
--- /dev/null
+++ b/src/EntityFrameworkCore.Projectables/Extensions/QueryableExtensions.cs
@@ -0,0 +1,15 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using EntityFrameworkCore.Projectables.Services;
+
+namespace EntityFrameworkCore.Projectables.Extensions
+{
+    public static class QueryableExtensions
+    {
+        public static IQueryable<TModel> ExpandQuaryables<TModel>(this IQueryable<TModel> query)
+            => query.Provider.CreateQuery<TModel>(query.Expression.ExpandQuaryables());
+    }
+}
diff --git a/src/EntityFrameworkCore.Projectables/Infrastructure/Internal/CustomQueryTranslationPreprocessorFactory.cs b/src/EntityFrameworkCore.Projectables/Infrastructure/Internal/CustomQueryTranslationPreprocessorFactory.cs
index 7809b8b..d561df4 100644
--- a/src/EntityFrameworkCore.Projectables/Infrastructure/Internal/CustomQueryTranslationPreprocessorFactory.cs
+++ b/src/EntityFrameworkCore.Projectables/Infrastructure/Internal/CustomQueryTranslationPreprocessorFactory.cs
@@ -4,6 +4,7 @@ using System.Linq;
 using System.Linq.Expressions;
 using System.Text;
 using System.Threading.Tasks;
+using EntityFrameworkCore.Projectables.Extensions;
 using EntityFrameworkCore.Projectables.Services;
 using Microsoft.EntityFrameworkCore.Query;
 
@@ -13,7 +14,6 @@ namespace EntityFrameworkCore.Projectables.Infrastructure.Internal
     {
         readonly IQueryTranslationPreprocessorFactory _decoratedFactory;
         readonly QueryTranslationPreprocessorDependencies _queryTranslationPreprocessorDependencies;
-        readonly ProjectableExpressionReplacer _projectableExpressionReplacer = new(new ProjectionExpressionResolver());
 
         public CustomQueryTranslationPreprocessorFactory(IQueryTranslationPreprocessorFactory decoratedFactory, QueryTranslationPreprocessorDependencies queryTranslationPreprocessorDependencies)
         {
@@ -22,21 +22,19 @@ namespace EntityFrameworkCore.Projectables.Infrastructure.Internal
         }
 
         public QueryTranslationPreprocessor Create(QueryCompilationContext queryCompilationContext)
-            => new CustomQueryTranslationPreprocessor(_decoratedFactory.Create(queryCompilationContext), _queryTranslationPreprocessorDependencies, queryCompilationContext, _projectableExpressionReplacer);
+            => new CustomQueryTranslationPreprocessor(_decoratedFactory.Create(queryCompilationContext), _queryTranslationPreprocessorDependencies, queryCompilationContext);
     }
 
     public class CustomQueryTranslationPreprocessor : QueryTranslationPreprocessor
     {
         readonly QueryTranslationPreprocessor _decoratedPreprocessor;
-        readonly ProjectableExpressionReplacer _projectableExpressionReplacer;
 
-        public CustomQueryTranslationPreprocessor(QueryTranslationPreprocessor decoratedPreprocessor, QueryTranslationPreprocessorDependencies dependencies, QueryCompilationContext queryCompilationContext, ProjectableExpressionReplacer projectableExpressionReplacer) : base(dependencies, queryCompilationContext)
+        public CustomQueryTranslationPreprocessor(QueryTranslationPreprocessor decoratedPreprocessor, QueryTranslationPreprocessorDependencies dependencies, QueryCompilationContext queryCompilationContext) : base(dependencies, queryCompilationContext)
         {
             _decoratedPreprocessor = decoratedPreprocessor;
-            _projectableExpressionReplacer = projectableExpressionReplacer;
         }
 
         public override Expression Process(Expression query)
-            => _decoratedPreprocessor.Process(_projectableExpressionReplacer.Visit(query));
+            => _decoratedPreprocessor.Process(query.ExpandQuaryables());
     }
 }
\ No newline at end of file