Visual Studio 2015 RC Typescript experimental decorators error

Question

How do I disable the following error in VS2015?

TS1219 Experimental support for decorators is a feature that is subject to change in a future release. Specify '--experimentalDecorators' to remove this warning.

I'm trying to use Angular2 annotations. I tried adding the following manually to the project file with no luck:

<TypeScriptExperimentalDecorators>True</TypeScriptExperimentalDecorators>

I've also install the TypeScript 1.5.0 beta extension.

Answer 1

Visual Studio 2015 supports tsconfig files starting with Typescript version 1.8. Create tsconfig.json file at the root of your project and add experimentalDecorators compiler option.

Example:

{
  "compileOnSave": true,
  "compilerOptions": {
    "module": "commonjs",
    "sourceMap": true,

    "experimentalDecorators": true
  }
}

For older versions:

https://github.com/Microsoft/TypeScript/issues/3934

If you have a project file, tsconfig will not be honored. the project file takes precedence. We are still flushing the integration story between a VS project and a tsconfig as you can specify compiler options in both.

so to disable the error message, right-click on project file, unload project, then right-click edit the project file, At the end of the file there should be a config section, add:

<PropertyGroup Condition="'$(Configuration)' == 'Debug'">
  ....
  <TypeScriptExperimentalDecorators>true</TypeScriptExperimentalDecorators>
</PropertyGroup>

save and reload.

You may also need TypeScriptEmitDecoratorMetadata to map --emitDecroatorMetadata