feat: option to ensure variable is within the list of values

[vmaerten]

An extension of requires vars.

Added the ability check if a variable is one of allowed values. It only works for string right now.

It useful when we call a task from the CLI using a var. For example :

version: '3'
tasks:
  deploy:
    cmds:
      - echo "deploying to {{.ENV}}"
    requires:
      vars:
        - name: ENV
          enum: [dev, beta, prod]

I want to be sure that the user can only deploy to those envs.

[mgbowman]

First off, awesome idea! 💪🏻

Maybe it's just me, but allowed_values seems a bit verbose.

What do you think about values or choices or options?

[pd93]

Maybe it's just me, but allowed_values seems a bit verbose.

What do you think about values or choices or options?

jsonschema uses enum for this: https://json-schema.org/understanding-json-schema/reference/enum

[vmaerten]

I like both values and enum

[pd93]

I'm fine with either. The only thing I will say in favor of enum or choices etc is that it makes it obvious that there is a constraint. values could be misinterpreted. i.e. are they allowed values? default values, will it loop over them etc.

[andreynering]

Between these options, I like enum the most.

[vmaerten]

I've asked to chatGPT (and some friends)

If clarity is your priority, allowed_values is solid.
If you're looking for something shorter but still clear, choices or enum are great picks. Enum has the advantage of being standardized in some communities.

Naming is hard (and cannot be modified after), we need to choose it carefully.

I think I'll go for enum

EDIT: I was writing. after seeing @andreynering thought. I'll use enum