Consider using ESM by default in JavaScript and TypeScript templates

[lukehoban]

Hello!

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Issue details

We now (pulumi/pulumi#7764, pulumi/pulumi#8655) support the use of ECMAScript modules as Pulumi entrypoints. We support this natively in JavaScript and in pre-compiled TypeScript, and via some additional custom flags (using experimental Node.js loader features) for on-the-fly-compiler TypeScript.

This also enables the use of await at top level in Pulumi programs as in pulumi/pulumi#5161 (comment).

At some point, we may want our templates to make this the default for all new projects. I don't think we can do that yet for TypeScript because the features we depend on our experimental, and have in practice seen breaking changes, so this would risk exposing users to breaking changes in Node.js in the future. Given that, I'm inclined to also leave JavaScript templates as is for now, so that JavaScript and TypeScript are consistent by default.

Once these Node.js features are sufficiently stable though, we can revisit this.

[simenandre]

Maybe we should create some of the basic templates with ESM? I was thinking about creating a guide, and it would be awesome if I could point to a template.

[vtereshyn]

I am trying to make it work with ESM configuration of my Pulumi project, but I am getting an error:

Error: Cannot find module './config.js'

Is there a way to not use module: "commonjs" that specified in Pulumi by default?

[jkodroff]

@lukehoban Is there a link to where we can track the upstream Node.js features?