Hi I have a Typescript newbie question about Pulumi outputs

Question

Hi I have a Typescript newbie question about Pulumi outputs and promises I would expect the following to work but I m getting a type error ```const promise = new Promise lt Map lt string string gt gt resolve reject = gt new Map lt string string gt const output pulumi Output lt Map lt string string gt gt = pulumi output promise ``` as it fails with ```TS2322 Type Output lt UnwrappedObject lt Map lt string string gt gt gt is not assignable to type Output lt Map lt string string gt gt Type Output lt UnwrappedObject lt Map lt string string gt gt gt is not assignable to type OutputInstance lt Map lt string string gt gt Types of property apply are incompatible Type lt U gt func t UnwrappedObject lt Map lt string string gt gt = gt Promise lt U gt Output lt U gt lt U gt func t UnwrappedObject lt Map lt string string gt gt = gt OutputInstance lt gt Output lt gt lt U gt func t UnwrappedObject lt gt = gt U Output lt gt is not assignable to type lt U gt func t Map lt string string gt = gt Promise lt U gt Output lt U gt lt U gt func t Map lt string string gt = gt OutputInstance lt U gt Output lt U gt lt U gt func t Map lt gt = gt U Output lt gt Types of parameters func and func are incompatible Types of parameters t and t are incompatible Type UnwrappedObject lt Map lt string string gt gt is missing the following properties from type Map lt string string gt Symbol iterator Symbol toStringTag ``` Am I missing something I thought that I can repackage whatever I have in the promise object into an output object

little-cartoon-10569 · Answer

I don t think you can do this by casting or wrapping the type of a `pulumi output x as Promise lt X gt ` is going to be an `Output lt Promise lt X gt ` Rather everywhere that you might use an Output or Promise actually takes an Input which is a union type including both the Output and the Promise So you can just ignore the requirement for an Output and use the Promise directly

little-cartoon-10569 · Answer

So you could rewrite your example code as ```const output = new Promise lt Map lt string string gt gt resolve reject = gt new Map lt string string gt ``` And use that output variable anywhere that needs an Input

gifted-island-55702 · Answer

Thank you < little cartoon 10569> The issue is I want to expose that value as an output property of my ComponentResource class My understanding is that I should use pulumi Output type in such cases

little-cartoon-10569 · Answer

You can use any type Things that you can pass an Output lt x gt to almost always take an Input lt x gt which is a union type defined as `x | Promise lt x gt | Output lt x gt ` You can export strings Promises of lists Outputs of numbers whatever you like

little-cartoon-10569 · Answer

And outputs of ComponentResources are just properties there is no magic to them The only output variables are those exported from Pulumi projects stacks Any public properties of ComponentResources of any time can be exported and Pulumi will handle it With the gotcha that there is no marshalling unmarshalling so if you re exporting non primitives you re going to have to marshal unmarshall them yourself