@action decorator creates an "actions" hash on the host object #19143

🐞 Describe the Bug

When using the @action decorator on a method, it tries to check if the object has an actions hash and do stuff with it. This breaks when the object happens to have an actions property that is not what it expects.

🔬 Minimal Reproduction

For example:

class MyComponent extends GlimmerComponent {
  get actions() {
    return this.args.actions.map(...);
  }
}

😕 Actual Behavior

It should not error.

🤔 Expected Behavior

It errors.

In this specific case, it errors because setupAction tries to call MyComponent.actions on the class, so the getter function is called with the wrong this (the class, not the instance) and it errors. In other case it may cause other more subtle failures, or in other cases it may just result in unnecessary work.

🌍 Environment

• Ember: 3.20

➕ Additional Context

I asked @rwjblue about this and he said it's most likely unintended behavior. His suggestion was that we check for actions being a concatenated property before doing this.