ytt strips out AWS SAM template !Ref, !Sub, etc. directives out of my values

[SnarfleBunny]

Is there a way I can keep those in the output YAML?

I have a subdir named etc/ which has this file in it:

#@ load("@ytt:data", "data")
AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Description: FOS REST API

#! Parameters

Parameters:

  DeployEnv:
    Type: String
    Default: #@ data.values.deploy_env
  UsagePlanType:
    Type: String
    Default: PER_API

#! Conditions

#! Globals

Globals:
  HttpApi:
    Auth:
      ApiKeyRequired: true
      UsagePlan:
        CreateUsagePlan: !Ref UsagePlanType

#! Resources

Resources:


  FosRestApi:
    Type: AWS::Serverless::HttpApi
    Properties:
      StageName: !Ref DeployEnv


#! Outputs

Here is values.yml:

#@data/values
---
deploy_env: dev

The following is what it produces:

AWSTemplateFormatVersion: "2010-09-09"
Transform: AWS::Serverless-2016-10-31
Description: FOS REST API
Parameters:
  DeployEnv:
    Type: String
    Default: dev
  UsagePlanType:
    Type: String
    Default: PER_API
Globals:
  HttpApi:
    Auth:
      ApiKeyRequired: true
      UsagePlan:
        CreateUsagePlan: UsagePlanType
Resources:
  FosRestApi:
    Type: AWS::Serverless::HttpApi
    Properties:
      StageName: DeployEnv

You will notice all the !Ref s are removed from the output. How do I let those directives remain in the output?

[cppforlife]

this seems like same issue as this: #74. here is a possible workaround i have mentioned #74 (comment). currently ytt doesnt have ability to preserve custom tags, hence it wouldnt work with above example.

[cppforlife]

closing this one, keeping #74