Bit of a TypeScript newbie here w a question on changes nece

Question

Bit of a TypeScript newbie here w a question on changes necessary to account for Remove synchronous invokes in Pulumi 2 x described at <https www pulumi com docs get started install migrating 2 0 > I was using `aws getAvailabilityZones` and using the results to a create an array of strings to capture the AZ names and b use the `length` function on said array of strings to determine how many AZs were in the region I thought that wrapping the `aws getAvailabilityZones` in `pulumi output` and then using `apply` would get me back to working but it appears not Code is threaded below

salmon-account-74572 · Answer

Here s the original TypeScript code I was using with Pulumi 1 x ```const rawAzInfo = aws getAvailabilityZones state available let azNames Array lt string gt = rawAzInfo names let numberOfAZs number = azNames length ```

salmon-account-74572 · Answer

Here s what I was trying to use w Pulumi 2 x ```const rawAzInfo = pulumi output aws getAvailabilityZones state available let azNames = rawAzInfo apply rawAzInfo = gt rawAzInfo names let numberOfAZs = azNames length ``` TS complains that I can t define `azNames` as `Array lt string gt ` because of type mismatch If I remove the type definition then I can t define `numberOfAZs` as a `number` due to type mismatch and then that breaks some numerical operations later in the code

salmon-account-74572 · Answer

As a relative newcomer to TypeScript I m a bit lost on how I can resolve this Suggestions

faint-table-42725 · Answer

Since you ll end up using the number later on I would treat it as a promise instead of wrapping in output Then either write your code w in the `then` of the promise or use <https www pulumi com docs intro languages javascript entrypoint> to use top level `await`

salmon-account-74572 · Answer

Thanks Can you suggest some reading that might help me better understand working with promises I ve tried a couple variations of using `then` to no avail so I think I need to spend some time understanding the concepts a bit better

faint-table-42725 · Answer

I don t have a go to resource for that I ve heard good things about <https www executeprogram com > and their concurrency lesson seems to be among the free lessons you can try