Remove-Migration null-refs when generating report

[pranavkm]

* Created a new 2.0.0 project
* Manually initialize EFCore.Tools (`&"C:\Program Files\dotnet\sdk\NuGetFallbackFolder\microsoft.entityframeworkcore.tools\2.0.0\tools\init.ps1"`)
* Invoke Add-Migration followed by removing it.

PM> Add-Migration test
Microsoft.AspNetCore.DataProtection.KeyManagement.XmlKeyManager[0]
      User profile is available. Using 'C:\Users\prkrishn\AppData\Local\ASP.NET\DataProtection-Keys' as key repository and Windows DPAPI to encrypt keys at rest.
Microsoft.EntityFrameworkCore.Infrastructure[100403]
      Entity Framework Core 2.0.0-rtm-26452 initialized 'ApplicationDbContext' using provider 'Microsoft.EntityFrameworkCore.Sqlite' with options: None
To undo this action, use Remove-Migration.

PM> Remove-Migration 
Microsoft.AspNetCore.DataProtection.KeyManagement.XmlKeyManager[0]
      User profile is available. Using 'C:\Users\prkrishn\AppData\Local\ASP.NET\DataProtection-Keys' as key repository and Windows DPAPI to encrypt keys at rest.
Microsoft.EntityFrameworkCore.Infrastructure[100403]
      Entity Framework Core 2.0.0-rtm-26452 initialized 'ApplicationDbContext' using provider 'Microsoft.EntityFrameworkCore.Sqlite' with options: None
Microsoft.EntityFrameworkCore.Database.Command[200101]
      Executed DbCommand (11ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
      PRAGMA foreign_keys=ON;
Microsoft.EntityFrameworkCore.Database.Command[200101]
      Executed DbCommand (0ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
      PRAGMA foreign_keys=ON;
Microsoft.EntityFrameworkCore.Database.Command[200101]
      Executed DbCommand (0ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
      SELECT COUNT(*) FROM "sqlite_master" WHERE "name" = '__EFMigrationsHistory' AND "type" = 'table';
Microsoft.EntityFrameworkCore.Database.Command[200101]
      Executed DbCommand (0ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
      PRAGMA foreign_keys=ON;
Microsoft.EntityFrameworkCore.Database.Command[200101]
      Executed DbCommand (0ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
      SELECT "MigrationId", "ProductVersion"
      FROM "__EFMigrationsHistory"
      ORDER BY "MigrationId";
Removing migration '20170727182640_test'.
Reverting model snapshot.
Done.
System.NullReferenceException: Object reference not set to an instance of an object.
   at Microsoft.EntityFrameworkCore.Tools.Json.Escape(String text)
   at Microsoft.EntityFrameworkCore.Tools.Commands.MigrationsRemoveCommand.ReportJsonResults(IDictionary result)
   at Microsoft.EntityFrameworkCore.Tools.Commands.MigrationsRemoveCommand.Execute()
   at Microsoft.DotNet.Cli.CommandLine.CommandLineApplication.Execute(String[] args)
   at Microsoft.EntityFrameworkCore.Tools.Program.Main(String[] args)
Object reference not set to an instance of an object.
{
  "migrationFile": "C:\\Users\\prkrishn\\test\\Data\\Migrations\\20170727182640_test.cs",
  "metadataFile": "C:\\Users\\prkrishn\\test\\Data\\Migrations\\20170727182640_test.Designer.cs",

The migration gets removed and the ps script returns a 0-exit code, but the error makes it appear something's gone wrong.

[bricelam]

Strange that we don't handle null in JSON. I wonder why we're just now seeing this.

[Eilon]

This patch bug is approved for the 2.0.x patch. Please send a PR to the feature/2.0.1 branch and get it reviewed and merged. When we have the rel/2.0.1 branches ready please port the commit to that branch.

[Eilon]

Hi, we have a public test feed that you can use to try out the ASP.NET/EF Core 2.0.3 patch!

To try out the pre-release patch, please refer to the following guide:

• ASP.NET/EF Core 2.0.3 patch pre-release test feed aspnet/Announcements#274 (info)
• ASP.NET/EF Core 2.0.3 patch pre-release test feed - discussion aspnetcore#2254 (discussions and questions)

We are looking for feedback on this patch. We'd like to know if you have any issues with this patch by updating your apps and libraries to the latest packages and seeing if it fixes the issues you've had, or if it introduces any new issues. If you have any issues or questions, please reply on this issue to let us know as soon as possible.

Thanks,
Eilon

[hidayatarg]

Strange that we don't handle null in JSON. I wonder why we're just now seeing this.
I solve this by installing the following packages for 2.0 core

<PackageReference Include="Microsoft.EntityFramworkCore.SqlServer" Version="2.1.4" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer.Design" Version="1.1.6" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="2.1.4">