Is it incorrect to re-use guards by parametizing them?

[christopher-francisco-jpmc]

I'm new to xstate and refactoring an existing machine. For simplicity, I've got something like this:

always: [
  { target: 'EAT',      cond: { type: 'isDoing', expected: 'hungry', actual: currentBehaviour },
  { target: 'SLEEP',  cond: { type: 'isDoing', expected: 'tired',     actual: currentBehaviour },
  // ...repeat for a total of 14 of these
]

...

guards: {
  isDoing: (_, _, { cond: { expected, actual } ) => expected === actual,

I haven't actually ran it as there are some other refactors in place; but the VSCode plugin is properly able to draw the diagram, so I'm assuming it runs.

The problem is, the VSCode plugin is showing a few orange question marks that say: Found 14 guards with the name 'isDoing' which leads me to believe that maybe I'm not supposed to be using the same guard multiple times like this.

I would appreciate some pointers, am I doing it wrong?

[davidkpiano]

Which version of XState are you using? It looks like you're using v4. This might be a problem with the extension.

But yes, in v5, you can use parameters and it's actually encouraged. See here: https://stately.ai/docs/guards#guard-object

[christopher-francisco-jpmc]

Yes this is v4, apologies I meant to include that info, but it slipped.

Should I?

• ignore it
• use guards differently
• look for a potential different problem that may be causing this warning/error to show

We will update to v5 in a few months but for the time being I have to focus in v4

[davidkpiano]

You can use parameterized guards in v4 as well. If you see any warning/error, that's probably a problem with the extension.