All Cfn Types broken for .NET in 0.35.0 and 0.36.0

[kuhnboy]

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• I'm submitting a ...

  • 🪲 bug report
  • 🚀 feature request
  • 📚 construct library gap
  • ☎️ security issue or vulnerability => Please see policy
  • ❓ support request => Please see note at the top of this template.

• What is the current behavior?
  Any command to create a CfnXXX object results in an exception when running cdk synth.

• What is the expected behavior (or behavior of feature suggested)?

• Create a new CDK project with 0.36.0
• Modify HelloStack to just do:
  var vpc = new CfnVPC(this, "vpc", new CfnVPCProps { CidrBlock = "10.180.0.0/16", EnableDnsHostnames = true, EnableDnsSupport = true });
• Run cdk synth
• Exception is thrown and error is outputted

• What is the motivation / use case for changing the behavior or adding this feature?

• Please tell us about your environment:

  • CDK CLI Version: 0.36.0
  • Module Version: 0.36.0
  • OS: Windows 10
  • Language: C#

• Other information (e.g. detailed explanation, stacktraces, related issues, suggestions how to fix, links for us to have context, eg. associated pull-request, stackoverflow, gitter, etc)

Unhandled Exception: Amazon.JSII.Runtime.JsiiException: Amazon.JSII.Runtime.JsiiException: Resolution error: System.ArgumentException: Object of type 'Newtonsoft.Json.Linq.JObject' cannot be converted to type 'System.Collections.Generic.IDictionary`2[System.String,System.Object]'.
   at System.RuntimeType.TryChangeType(Object value, Binder binder, CultureInfo culture, Boolean needsSpecialCast)
   at System.Reflection.MethodBase.CheckArguments(Object[] parameters, Binder binder, BindingFlags invokeAttr, CultureInfo culture, Signature sig)
   at System.Reflection.RuntimeMethodInfo.InvokeArgumentsCheck(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at Amazon.JSII.Runtime.CallbackExtensions.InvokeMethod(InvokeRequest request, IReferenceMap referenceMap)
   at Amazon.JSII.Runtime.CallbackExtensions.InvokeCallback(Callback callback, IReferenceMap referenceMap, IFrameworkToJsiiConverter converter, String& error).
Object creation stack:
  at new Intrinsic (C:\Users\rkuhn\AppData\Local\Temp\jsii-kernel-cSWmAu\node_modules\@aws-cdk\core\lib\private\intrinsic.js:20:44)
  at new PostResolveToken (C:\Users\rkuhn\AppData\Local\Temp\jsii-kernel-cSWmAu\node_modules\@aws-cdk\core\lib\util.js:72:9)
  at CfnVPC._toCloudFormation (C:\Users\rkuhn\AppData\Local\Temp\jsii-kernel-cSWmAu\node_modules\@aws-cdk\core\lib\cfn-resource.js:167:39)
  at node.addReference.resolve_1.findTokens (C:\Users\rkuhn\AppData\Local\Temp\jsii-kernel-cSWmAu\node_modules\@aws-cdk\core\lib\cfn-element.js:84:77)
  at Object.findTokens (C:\Users\rkuhn\AppData\Local\Temp\jsii-kernel-cSWmAu\node_modules\@aws-cdk\core\lib\private\resolve.js:125:13)
  at CfnVPC.prepare (C:\Users\rkuhn\AppData\Local\Temp\jsii-kernel-cSWmAu\node_modules\@aws-cdk\core\lib\cfn-element.js:84:49)
  at _wrapSandboxCode (C:\Users\rkuhn\AppData\Local\Temp\yx5e5zrf.sf5\jsii-runtime.js:6493:51)
  at Kernel._wrapSandboxCode (C:\Users\rkuhn\AppData\Local\Temp\yx5e5zrf.sf5\jsii-runtime.js:7126:20)
  at ret._ensureSync (C:\Users\rkuhn\AppData\Local\Temp\yx5e5zrf.sf5\jsii-runtime.js:6493:25)
  at Kernel._ensureSync (C:\Users\rkuhn\AppData\Local\Temp\yx5e5zrf.sf5\jsii-runtime.js:7097:20)
  at Kernel.invoke (C:\Users\rkuhn\AppData\Local\Temp\yx5e5zrf.sf5\jsii-runtime.js:6492:26)
  at KernelHost.processRequest (C:\Users\rkuhn\AppData\Local\Temp\yx5e5zrf.sf5\jsii-runtime.js:6186:28)
  at completeCallback (C:\Users\rkuhn\AppData\Local\Temp\yx5e5zrf.sf5\jsii-runtime.js:6159:25)
  at KernelHost.callbackHandler (C:\Users\rkuhn\AppData\Local\Temp\yx5e5zrf.sf5\jsii-runtime.js:6140:16)
  at KernelHost.kernel.jsii_kernel_1.Kernel.cb [as callbackHandler] (C:\Users\rkuhn\AppData\Local\Temp\yx5e5zrf.sf5\jsii-runtime.js:6124:59)
  at CfnVPC.value (C:\Users\rkuhn\AppData\Local\Temp\yx5e5zrf.sf5\jsii-runtime.js:6843:41)
  at Function.prepare (C:\Users\rkuhn\AppData\Local\Temp\jsii-kernel-cSWmAu\node_modules\@aws-cdk\core\lib\construct.js:91:27)
  at Function.synth (C:\Users\rkuhn\AppData\Local\Temp\jsii-kernel-cSWmAu\node_modules\@aws-cdk\core\lib\construct.js:54:14)
  at App.synth (C:\Users\rkuhn\AppData\Local\Temp\jsii-kernel-cSWmAu\node_modules\@aws-cdk\core\lib\app.js:67:52)
  at _wrapSandboxCode (C:\Users\rkuhn\AppData\Local\Temp\yx5e5zrf.sf5\jsii-runtime.js:6493:51)
  at Kernel._wrapSandboxCode (C:\Users\rkuhn\AppData\Local\Temp\yx5e5zrf.sf5\jsii-runtime.js:7126:20)
  at ret._ensureSync (C:\Users\rkuhn\AppData\Local\Temp\yx5e5zrf.sf5\jsii-runtime.js:6493:25)
  at Kernel._ensureSync (C:\Users\rkuhn\AppData\Local\Temp\yx5e5zrf.sf5\jsii-runtime.js:7097:20)
  at Kernel.invoke (C:\Users\rkuhn\AppData\Local\Temp\yx5e5zrf.sf5\jsii-runtime.js:6492:26)
  at KernelHost.processRequest (C:\Users\rkuhn\AppData\Local\Temp\yx5e5zrf.sf5\jsii-runtime.js:6186:28)
  at KernelHost.run (C:\Users\rkuhn\AppData\Local\Temp\yx5e5zrf.sf5\jsii-runtime.js:6132:14)
  at processRequest (C:\Users\rkuhn\AppData\Local\Temp\yx5e5zrf.sf5\jsii-runtime.js:6132:45)
  at KernelHost.processRequest (C:\Users\rkuhn\AppData\Local\Temp\yx5e5zrf.sf5\jsii-runtime.js:6228:16)
  at KernelHost.run (C:\Users\rkuhn\AppData\Local\Temp\yx5e5zrf.sf5\jsii-runtime.js:6132:14)
  at processRequest (C:\Users\rkuhn\AppData\Local\Temp\yx5e5zrf.sf5\jsii-runtime.js:6132:45)
  at KernelHost.processRequest (C:\Users\rkuhn\AppData\Local\Temp\yx5e5zrf.sf5\jsii-runtime.js:6228:16)
  at KernelHost.run (C:\Users\rkuhn\AppData\Local\Temp\yx5e5zrf.sf5\jsii-runtime.js:6132:14)
  at processRequest (C:\Users\rkuhn\AppData\Local\Temp\yx5e5zrf.sf5\jsii-runtime.js:6132:45)
  at KernelHost.processRequest (C:\Users\rkuhn\AppData\Local\Temp\yx5e5zrf.sf5\jsii-runtime.js:6228:16)
  at KernelHost.run (C:\Users\rkuhn\AppData\Local\Temp\yx5e5zrf.sf5\jsii-runtime.js:6132:14)
  at processRequest (C:\Users\rkuhn\AppData\Local\Temp\yx5e5zrf.sf5\jsii-runtime.js:6132:45)
  at KernelHost.processRequest (C:\Users\rkuhn\AppData\Local\Temp\yx5e5zrf.sf5\jsii-runtime.js:6228:16)
  at KernelHost.run (C:\Users\rkuhn\AppData\Local\Temp\yx5e5zrf.sf5\jsii-runtime.js:6132:14)
  at processRequest (C:\Users\rkuhn\AppData\Local\Temp\yx5e5zrf.sf5\jsii-runtime.js:6132:45)
  at promise.then.val (C:\Users\rkuhn\AppData\Local\Temp\yx5e5zrf.sf5\jsii-runtime.js:6213:21)
  at <anonymous>
   at Amazon.JSII.Runtime.Services.Client.TryDeserialize[TResponse](String responseJson)
   at Amazon.JSII.Runtime.Services.Client.ReceiveResponse[TResponse]()
   at Amazon.JSII.Runtime.Services.Client.TryDeserialize[TResponse](String responseJson)
   at Amazon.JSII.Runtime.Services.Client.ReceiveResponse[TResponse]()
   at Amazon.JSII.Runtime.Deputy.DeputyBase.<InvokeMethodCore>g__GetResult|18_0[T](<>c__DisplayClass18_0`1& )
   at Amazon.JSII.Runtime.Deputy.DeputyBase.InvokeMethodCore[T](JsiiMethodAttribute methodAttribute, Object[] arguments, Func`3 beginFunc, Func`3 invokeFunc)
   at Amazon.JSII.Runtime.Deputy.DeputyBase.InvokeInstanceMethod[T](Object[] arguments, String methodName)
   at Amazon.CDK.CfnElement.Prepare()
   at Amazon.JSII.Runtime.Services.Client.TryDeserialize[TResponse](String responseJson)
   at Amazon.JSII.Runtime.Services.Client.ReceiveResponse[TResponse]()
   at Amazon.JSII.Runtime.Services.Client.TryDeserialize[TResponse](String responseJson)
   at Amazon.JSII.Runtime.Services.Client.ReceiveResponse[TResponse]()
   at Amazon.JSII.Runtime.Deputy.DeputyBase.<InvokeMethodCore>g__GetResult|18_0[T](<>c__DisplayClass18_0`1& )
   at Amazon.JSII.Runtime.Deputy.DeputyBase.InvokeMethodCore[T](JsiiMethodAttribute methodAttribute, Object[] arguments, Func`3 beginFunc, Func`3 invokeFunc)
   at Amazon.JSII.Runtime.Deputy.DeputyBase.InvokeInstanceMethod[T](Object[] arguments, String methodName)
   at HelloCdk.Program.Main(String[] args) in C:\source\foo\src\HelloCdk\Program.cs:line 19
Subprocess exited with error 3762504530

[kuhnboy]

Rolling back to each version this appears to be broken in 0.35.0 as well, but works in 0.34.0

[eladb]

Thanks for reporting

[eladb]

Repro:

using Amazon.CDK;
using Amazon.CDK.AWS.SNS;

namespace HelloCdk
{
    public class HelloStack : Stack
    {
        public HelloStack(Construct parent, string id, IStackProps props) : base(parent, id, props)
        {
            new CfnTopic_(this, "FOO", null);
        }
    }
}

[RomainMuller]

So I think I have gained some understanding of what is going wrong here. There's a combination of multiple factors stemming from how JSII will get values passed back-and-forth between the .NET process and the Node process.

Apparently, when objects are passed from JS to .NET by value (and not by reference), the .NET runtime deserializes those as JObject regardless of the actual type the method being invoked expects.

I am trying to come up with a minimal repro on the JSII side alone, but it is quite challenging. A full blown fix might also be quite difficult to author (but maybe I'm wrong - I'll see clearer into this once I manage to get that minimal JSII repro).