I have a lot of

dangling

Pulumi resources in my (TypeScript) stacks, resources which are created but not used as input to any other resource and which are neither added to any output nor returned from the main inline function (using the automation api). Looking at many Pulumi examples this seems to be a common pattern. Think of something like this:

function createBucket() {
   // Create AWS S3 Bucket but do neither output nor return it. It is also not used 
   // as input to any other resource.
   new Bucket("myBucket", {...});
}

However, rather often I observe that such resources are not created on first stack deployment resp. are delete on later stack updates. It looks like it depends on some “race condition” (timing issue) whether those resources are registered by the Pulumi runtime or not. Usually adding such

dangling

resources as dependency to another resource (using

dependsOn

), or alternatively making it a stack output resp. returning it from the main inline function resolves that (racy) problem. Now I am wondering, is this expected behaviour when using Pulumi with TypeScript/NodeJs or is this a bug in Pulumi?

@dry-football-2639 I had a similar issue the other day - are you creating resources in a non-index file, and then re-exporting them from the index file? e.g. your above code snippet in

buckets.ts

and then

export * from './buckets';

in

index.ts

?

@cuddly-father-4905 Yes, that is exactly what I am doing.

@dry-football-2639 in that case, I found that manually importing and exporting modules works far better than just re-exporting them, e.g.

import * as buckets from './buckets';

export {
  buckets
};

It's not as clean as just re-exporting, but it seems to have resolved this issue for me so far

@cuddly-father-4905 Do you have any background information on this (any pointer to a GitHub ticket/discussion, documentation, …)?

@dry-football-2639 unfortunately not; I couldn't find anything about it myself, and arrived at this solution just via trial and error

@cuddly-father-4905 I believe you're tagging the wrong Alex 🙂

Woops, sorry haha CC @busy-honey-73811 ^

@cuddly-father-4905 OK, thanks for the hint, I will check whether this might help in my case.

This is for better or worse part of how TypeScript works by default. `import`s which don't use any values from the import get elided and are not emitted as `require`s in the JavaScript code, and therefore don't cause any side effects that loading the module might ensure happen. See for example https://github.com/microsoft/TypeScript/issues/2812. That said - it looks like TypeScript 3.8 added a flag to control this behaviour: https://www.typescriptlang.org/tsconfig/#importsNotUsedAsValues. We should almost certainly set that to

preserve

by default for Pulumi projects since these style of side effects are very common in Pulumi programs.

@white-balloon-205 Thanks for those insights and creating the ticket. I will set

importsNotUsedAsValues

to

preserve

for my TypeScript stacks.