[FEATURE]: implement number() cast helper function similar to existing string() function

[stefreak]

Feature Request

Allow parsing a string as a number

Background / Motivation

When using output from other actions, or command-line parameter they will be presented as string type

An template expression like this: --flag=${var.x * 2} would then result in the error

Invalid template string (--flag=${var.x * 2}) at path ...: Both terms need to be numbers for * operator (got string and number).

What should the user be able to do?

parse strings as numbers using a template helper function; Example --flag=${number(var.x) * 2}

Why do they want to do this? What problem does it solve?

Makes it easier to write glue code

Suggested Implementation(s)

We can add a helper function similar to the existing string() function, that parses the number.

Open question: What should the function do with floating point and integers that are not base 10?

Workaround

It's possible to (ab)use the jsonDecode helper like so: ${string(jsonDecode("2") * 4)}
This expression will resolve to the number 8.

How important is this feature for you/your team?

🌹 It’s a nice to have, but nice things are nice 🙂