Add inheritdoc to migration files

It would be nice if dotnet ef migrations add would automatically add

#pragma warning disable CS1591 // Missing XML comment for publicly visible type or member

to the beginning of generated file and

#pragma warning restore CS1591 // Missing XML comment for publicly visible type or member

at the end of file. I mean both (migrations and designer).

For example:

#pragma warning disable CS1591 // Missing XML comment for publicly visible type or member

using Microsoft.EntityFrameworkCore.Migrations;
using System;
using System.Collections.Generic;

namespace OpPIS.Web.Hosting.Migrations
{
    public partial class Fix5 : Migration
    {
        protected override void Up(MigrationBuilder migrationBuilder)
        {
            migrationBuilder.AddColumn<int>(
                name: "ParentAnchorX",
                table: "VarDesign_Parameter-ImageManipulations",
                nullable: true);
        }

        protected override void Down(MigrationBuilder migrationBuilder)
        {
            migrationBuilder.DropColumn(
                name: "ParentAnchorX",
                table: "VarDesign_Parameter-ImageManipulations");
        }
    }
}

#pragma warning restore CS1591 // Missing XML comment for publicly visible type or member

[ajcvickers]

@MaklaCof We will have a think about adding XML comments to the generated code, but we don’t plan to do it at the present time. Beyond that, we don’t want to generate this pragma all the time because most people will not need it. However, there is a similar discussion about auto-generated in issue #10203. I posted a code snippet in that issue showing how to override the generator to add a line–this should also work for the pragma.

[bobvandevijver]

For reference in this ticket, this is what I used to generate the pragma’s:

public class FooMigrationsGenerator : CSharpMigrationsGenerator
{
    private const string PragmaWarningDisable = @"#pragma warning disable 1591";
    private const string PragmaWarningRestore = @"#pragma warning restore 1591";

    public FooMigrationsGenerator(
        MigrationsCodeGeneratorDependencies dependencies, CSharpMigrationsGeneratorDependencies csharpDependencies)
        : base(dependencies, csharpDependencies)
    {
    }

    public override string GenerateMigration(string migrationNamespace, string migrationName,
                                             IReadOnlyList<MigrationOperation> upOperations,
                                             IReadOnlyList<MigrationOperation> downOperations)
    {
        return PragmaWarningDisable
               + Environment.NewLine
               + base.GenerateMigration(migrationNamespace, migrationName, upOperations, downOperations)
               + Environment.NewLine
               + PragmaWarningRestore
               + Environment.NewLine;
    }

    public override string GenerateMetadata(string migrationNamespace, Type contextType, string migrationName,
                                            string migrationId, IModel targetModel)
        => PragmaWarningDisable
           + Environment.NewLine
           + base.GenerateMetadata(migrationNamespace, contextType, migrationName, migrationId, targetModel)
           + Environment.NewLine
           + PragmaWarningRestore
           + Environment.NewLine;
}

Together with this class somewhere in the starting assembly:

public class DesignTimeServices : IDesignTimeServices
{
    /// <inheritdoc />
    public void ConfigureDesignTimeServices(IServiceCollection services)
    {
        // Register custom migration generator which adds a pragma disable for xml-comments
        services.AddSingleton<IMigrationsCodeGenerator, FooMigrationsGenerator>();
    }
}