SqlFile crashes Visual Studio

[mrinaldi]

Description

Using SqlFile and changing the file used by SqlFile throw a NullReferenceException.

Repro steps

1. Create a .sql file and use SqlFile provider.
2. Change the contents of the .sql file and saves.

Expected behavior

No crash

Actual behavior

Visual Studio crashes with:

Application: devenv.exe
Framework Version: v4.0.30319
Description: The process was terminated due to an unhandled exception.
Exception Info: System.NullReferenceException
   at System.Runtime.Caching.MemoryCacheStore.RemoveFromCache(System.Runtime.Caching.MemoryCacheEntry, System.Runtime.Caching.CacheEntryRemovedReason, Boolean)
   at System.Runtime.Caching.MemoryCacheStore.Remove(System.Runtime.Caching.MemoryCacheKey, System.Runtime.Caching.MemoryCacheEntry, System.Runtime.Caching.CacheEntryRemovedReason)
   at System.Runtime.Caching.MemoryCache.RemoveEntry(System.String, System.Runtime.Caching.MemoryCacheEntry, System.Runtime.Caching.CacheEntryRemovedReason)
   at System.Runtime.Caching.MemoryCacheEntry.OnDependencyChanged(System.Object)
   at System.Runtime.Caching.ChangeMonitor.OnChangedHelper(System.Object)
   at System.Runtime.Caching.ChangeMonitor.OnChanged(System.Object)
   at FSharp.Data.SqlClient.SingleFileChangeMonitor.TriggerOnChange()
   at FSharp.Data.SqlClient.SingleFileChangeMonitor.TriggerOnFileChange(System.String)
   at <StartupCode$FSharp-Data-SqlClient>.$SingleFileChangeMonitor+-ctor@19-61.Invoke(System.IO.FileSystemEventArgs)
   at Microsoft.FSharp.Control.CommonExtensions+SubscribeToObservable@2103[[System.__Canon, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]].System-IObserver`1-OnNext(System.__Canon)
   at Microsoft.FSharp.Core.CompilerServices.RuntimeHelpers+h@788[[System.__Canon, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]].Invoke(System.Object, System.__Canon)
   at <StartupCode$FSharp-Data-SqlClient>.$SingleFileChangeMonitor+-ctor@19-60.Invoke(System.Object, System.IO.FileSystemEventArgs)
   at System.IO.FileSystemWatcher.OnDeleted(System.IO.FileSystemEventArgs)
   at System.IO.FileSystemWatcher.NotifyFileSystemEventArgs(Int32, System.String)
   at System.IO.FileSystemWatcher.CompletionStatusChanged(UInt32, UInt32, System.Threading.NativeOverlapped*)
   at System.Threading._IOCompletionCallback.PerformIOCompletionCallback(UInt32, UInt32, System.Threading.NativeOverlapped*)

Known workarounds

Restart Visual Studio.

Related information

• Operating system: Windows 10 AU
• Branch: master
• Database versions and sample databases being used: Doesn't matter
• Editing Tools: Visual Studio 2015

[smoothdeveloper]

I confirm that I'm getting crashes when changing the .sql files. Any chance to get a new beta release?

[dsevastianov]

Sorry, I'm a bit confused. I couldn't reproduce the issue so far with Test solution using ConfigurationTest.fs. Are you getting it in script or regular .fs file?

[smoothdeveloper]

@dsevastianov I reproduce it with .fs file in a project, I'm using literal connection strings:

// this is auto generated by generate_queries.fsx
namespace SchemaAgnosticQueries
  open FSharp.Data
  module internal Literals =
    let [<Literal>] ``check.database.exists.sql`` = __SOURCE_DIRECTORY__ + @"/../../../../../Database/convention.queries/mssql/check.database.exists.sql"
  open Literals
  type checkDatabaseExistsQuery = SqlCommandProvider< const(SqlFile<``check.database.exists.sql``>.Text),  @"Data Source=(localdb)\v12.0;;User Id=sa;Password=password;Connection Timeout=60", SingleRow = true, AllParametersOptional = false, ResultType = ResultType.Records>

when I change that check.database.exists.sql file, VS crashes:

[mrinaldi]

I'm getting this after editing the .sql file.

[dsevastianov]

Please excuse my ignorance but what's

const(SqlFile<``check.database.exists.sql``>.Text) 

?

I can't compile this code in Test solution. To the best of my knowledge const is a keyword reserved for future use in F# up to 4.0, am I missing something?

Here's the closest I could get to reproducing in Test solution but I still don't get the exception. My setup is VS 2015 Update 3, SqlClient.Tests project targets F# 3.1 (FSharp.Core, 4.3.1.0)

let [<Literal>] ``check.database.exists.sql`` = __SOURCE_DIRECTORY__ + "\sampleCommand.sql"
let [<Literal>] Query = SqlFile<``check.database.exists.sql``>.Text

type checkDatabaseExistsQuery = SqlCommandProvider< Query,  @"Data Source=(localdb)\ProjectsV13;Initial Catalog=AdventureWorks2012;Integrated Security=True", SingleRow = true, AllParametersOptional = false, ResultType = ResultType.Records>

[smoothdeveloper]

@dsevastianov const is required when constructing a literal as arguments of a type provider instantiation, you can see how it is used to work around a compiler limitation: dotnet/fsharp#1265 (comment)

Your code is equivalent as mine, I used const to avoid defining more symbols than needed.

[dsevastianov]

I see, thanks, I still can't reproduce this though. If Pr would include actual test for this that would be ideal.

[smoothdeveloper]

@dsevastianov can you try having the .fs file open in VS where the sql command is actually in use?

[smoothdeveloper]

@dsevastianov I've opened an issue in visualfsharp repository because I think they might want to prevent such crash to happen in any case dotnet/fsharp#2008

There are detailled reproduce steps in the issue with a sample project.