From f021aa03bfbdeb7e254f3df3b879cdb4a94dfe76 Mon Sep 17 00:00:00 2001
From: Simon Reynolds <github@simonreynolds.ie>
Date: Wed, 31 Mar 2021 16:40:03 +0100
Subject: [PATCH] Always include System namespace in generated Migrations

---
 .../Design/FSharpMigrationsGenerator.fs       | 48 ++++++++-----------
 .../Design/FSharpMigrationsGeneratorTest.fs   |  1 +
 2 files changed, 20 insertions(+), 29 deletions(-)

diff --git a/src/EFCore.FSharp/Migrations/Design/FSharpMigrationsGenerator.fs b/src/EFCore.FSharp/Migrations/Design/FSharpMigrationsGenerator.fs
index 3e3bfc5..686dea2 100644
--- a/src/EFCore.FSharp/Migrations/Design/FSharpMigrationsGenerator.fs
+++ b/src/EFCore.FSharp/Migrations/Design/FSharpMigrationsGenerator.fs
@@ -33,24 +33,30 @@ type FSharpMigrationsGenerator(dependencies, fSharpDependencies : FSharpMigratio
     let mutable tempDownOperations = list.Empty
     let mutable tempMigrationName = String.Empty
 
+    let getDefaultNamespaces (contextType: Type) =
+        seq {
+                 "System"
+                 "Microsoft.EntityFrameworkCore"
+                 "Microsoft.EntityFrameworkCore.Infrastructure"
+                 "Microsoft.EntityFrameworkCore.Metadata"
+                 "Microsoft.EntityFrameworkCore.Migrations"
+                 "Microsoft.EntityFrameworkCore.Storage.ValueConversion"
+
+                 if contextType.Namespace |> String.IsNullOrEmpty |> not then
+                    contextType.Namespace
+        } |> Seq.toList
+
     member private this.GenerateMigrationImpl (migrationNamespace) (migrationName) (migrationId: string) (contextType:Type) (upOperations) (downOperations) (model) =
         let sb = IndentedStringBuilder()
 
         let allOperations = (upOperations |> Seq.append downOperations)
 
-        let operationNamespaces = this.GetNamespaces allOperations
-        
+        let operationNamespaces = this.GetNamespaces allOperations |> Seq.toList
+
         let namespaces =
-            [ "Microsoft.EntityFrameworkCore"
-              "Microsoft.EntityFrameworkCore.Infrastructure"
-              "Microsoft.EntityFrameworkCore.Metadata"
-              "Microsoft.EntityFrameworkCore.Migrations"
-              "Microsoft.EntityFrameworkCore.Storage.ValueConversion" ]
-            |> Seq.append operationNamespaces
-            |> Seq.append [contextType.Namespace]
-            |> Seq.filter (isNull >> not)
-            |> Seq.toList
+            (getDefaultNamespaces contextType @ operationNamespaces)
             |> sortNamespaces
+            |> Seq.distinct
 
         sb
         |> appendAutoGeneratedTag
@@ -99,26 +105,10 @@ type FSharpMigrationsGenerator(dependencies, fSharpDependencies : FSharpMigratio
     member private this.GenerateSnapshotImpl (modelSnapshotNamespace: string) (contextType: Type) (modelSnapshotName: string) (model: IModel) =
         let sb = IndentedStringBuilder()
 
-        let defaultNamespaces =
-            seq {
-                 "System"
-                 "Microsoft.EntityFrameworkCore"
-                 "Microsoft.EntityFrameworkCore.Infrastructure"
-                 "Microsoft.EntityFrameworkCore.Metadata"
-                 "Microsoft.EntityFrameworkCore.Migrations"
-                 "Microsoft.EntityFrameworkCore.Storage.ValueConversion"
-
-                 if contextType.Namespace |> String.IsNullOrEmpty |> not then
-                    contextType.Namespace
-            }
-            |> Seq.toList
-
-        let modelNamespaces =
-            this.GetNamespaces model
-            |> Seq.toList
+        let modelNamespaces = this.GetNamespaces model |> Seq.toList
 
         let namespaces =
-            (defaultNamespaces @ modelNamespaces)
+            (getDefaultNamespaces contextType @ modelNamespaces)
             |> sortNamespaces
             |> Seq.distinct
 
diff --git a/tests/EFCore.FSharp.Tests/Migrations/Design/FSharpMigrationsGeneratorTest.fs b/tests/EFCore.FSharp.Tests/Migrations/Design/FSharpMigrationsGeneratorTest.fs
index b931b01..799d85e 100644
--- a/tests/EFCore.FSharp.Tests/Migrations/Design/FSharpMigrationsGeneratorTest.fs
+++ b/tests/EFCore.FSharp.Tests/Migrations/Design/FSharpMigrationsGeneratorTest.fs
@@ -621,6 +621,7 @@ module FSharpMigrationsGeneratorTest =
                 let expectedCode = """// <auto-generated />
 namespace MyNamespace
 
+open System
 open System.Text.RegularExpressions
 open EntityFrameworkCore.FSharp.Test.Migrations.Design
 open Microsoft.EntityFrameworkCore