[sdk/nodejs] Keep prompt values prompt in construct

[justinvp]

In order to support prompt values in multi-lang components, if an input value is prompt, keep it as-is instead of wrapping it in an Output.

Part of #6425

[t0yv0]

This made me think a little bit, trying to type check this in my head. Somehow from the test it's evident that children: Optional[Int] travels through this code just fine, but how is that value represented here is not obvious to me. I also wonder about the condition (!isSecret && deps.length === 0). I don't know yet what inputDependencies are very well.

Would this code confuse T and Input<T> or it does not matter? I imagine there is a way to lift pure :: T -> Input<T> and that pure(x) should not have any dependencies so presumably it would satisfy deps.length == 0?

[justinvp]

inputDependencies is documented in the .proto:

pulumi/sdk/proto/provider.proto

Line 267 in 3dde9d0

map<string, PropertyDependencies> inputDependencies = 11; // a map from property keys to the dependencies of the property.

pulumi/sdk/proto/provider.proto

Lines 251 to 254 in 3dde9d0

	// PropertyDependencies describes the resources that a particular property depends on.
	message PropertyDependencies {
	repeated string urns = 1; // A list of URNs this property depends on.
	}

If the property was assigned an output of another resource, or the result of an apply from one or more outputs, then the property will have an associated list of resource URNs that the property depends on. If there aren't any dependencies associated with the property, then we don't need to project it as an Output because we don't have any dependencies to track. Unless it's a secret: secrets in the type system are typed as Output<T> (we did this rather than having a separate Secret<T> type to keep the programming model simpler), so in that case, we need to wrap the value as Output<T>.

We don't have a specific flag that says "Property 'foo' was set a plain value", so instead, we just see whether the raw gRPC value can remain a plain value, otherwise we wrap it as an output. We're sort of relying on the type system of the generated SDK to indicate that the type of the value should be T and not Input<T>, but in some languages that don't have a real type system (e.g. JavaScript/Python), someone could force passing an Output, so right now we're sort of relying on type checking to prevent that. We should probably add some runtime type checking for JS/Python for plain values, to further help prevent that from happening.

Would this code confuse T and Input<T> or it does not matter?

Input<T> can be T or Output<T>:

pulumi/sdk/nodejs/output.ts

Line 727 in 3dde9d0

export type Input<T> = T | Promise<T> | OutputInstance<T>;

If an input property is typed as accepting an Input<T>, it can be given a T, and it'll just work.

[t0yv0]

I didn't realize there's a problem here want to take a look now.