This is an excellent list, thanks for making it! I think it's a good idea, and an eslint plugin for XState is generally a good idea as well.

Thanks for the encouragement @davidkpiano! Already have a few rules working 😁

I need to think about how this would behave but after talking to @Andarist earlier, we likely need a rule to encourage static configs. Bidirectional editing between code and Studio requires semi-static configs, so the more we can encourage static configs, the better things will be.

Basically we want users to avoid evaluating/computing things in their machine definitions:

const IDLE = 'idle'
const a = 'action'
const b = 1

const machine = createMachine(
  {
    // no vars as values
    initial: IDLE,
    // no `TemplateLiteral`s that require evaluation
    entry: `${a}${b}`,
    states: {
      // no computed properties
      [IDLE]: {}
    }
  },
  {
    actions: {
      action1: () => {},
    }
  }
)

I need to think about how this would behave but after talking to @Andarist earlier, we likely need a rule to encourage static configs. Bidirectional editing between code and Studio requires semi-static configs, so the more we can encourage static configs, the better things will be.

Basically we want users to avoid evaluating/computing things in their machine definitions:

const IDLE = 'idle'
const a = 'action'
const b = 1

const machine = createMachine(
  {
    // no vars as values
    initial: IDLE,
    // no `TemplateLiteral`s that require evaluation
    entry: `${a}${b}`,
    states: {
      // no computed properties
      [IDLE]: {}
    }
  },
  {
    actions: {
      action1: () => {},
    }
  }
)

In the future, I feel like it should be possible to even have some of these work with bidirectional editing. If we treat the AST like a directed graph, then it's a matter of taking one extra "step" to find the source of the value, and modifying it there (as long as it's not shared anywhere non-machine-related).

Computed properties are not uncommon, so I'm wondering if we can't at least support that.

as long as it's not shared anywhere non-machine-related

Can you clarify what that means?

If we treat the AST like a directed graph, then it's a matter of taking one extra "step" to find the source of the value,

I agree that it's possible to resolve (and even modify) a lot of pattern.

(as long as it's not shared anywhere non-machine-related).

This is a major blocker though - and how do you make this intuitive so people would know where the line between supported patterns and unsupported ones is?