Fix panic when environment uses computed values

[seanyeh]

Fixes #411

This is related to #399

Example repro program:

import * as pulumi from "@pulumi/pulumi";
import * as service from "@pulumi/pulumiservice";
import * as aws from "@pulumi/aws";

const org = "big-org";
const bucket = new aws.s3.Bucket("myBucket", {
    bucket: "syeh-panic-test",
    acl: "private",
});

const envDef = pulumi.interpolate`values:
  myKey1: "${bucket.arn}"`;
const envAsset = envDef.apply(x => new pulumi.asset.StringAsset(x));

const environment = new service.Environment("panic", {
  organization: org,
  project: "abc",
  name: "panic",
  yaml: envAsset,
})

[komalali]

Hmm... does this mean there will be no yamlBytes if it's computed? Or does this only affect Check and the resolved value of environment.yaml is still correct?

[seanyeh]

This only affects Check. I have confirmed the resolved value is still correct (I'm assuming that it's ok to not have computed values during Check?)

[komalali]

The purpose of this Check is to take the string value of the yaml and put that into state, so there's always a string value to compare against. In this case, when it's computed, it'll result in yaml being empty in state. So next time there's an update, there will be a diff because there is no value for yaml. You can test this by adding an example test similar to in https://github.com/pulumi/pulumi-pulumiservice/pull/391/files

We'll need a way to get the string value even out of the computed property I think.

[pgavlin]

Computed/unknown values will only appear during a preview, so I think that this will be okay. We'll re-run the Check during the update, at which point all values will be known.

[pgavlin]

Though I do think I'd do this slightly differently--instead of checking IsAsset I'd check for !IsComputed.

[pgavlin]

can we add a test for this (do we have tests for the provider in here in general)?