Way of extending ActionType to have type definition for action added with setActionType

[JacopoPatroclo]

Issue

Currently, when creating a new action type using the setActionType function, there's no direct provision to extend the ActionType type to include the new type and options type. It would be beneficial to add the ability to extend the ActionType type, simplifying the process for developers to share custom action types.

Proposal

It could be nice to have something like this:

declare module 'node-plop' {
   interface ActionType extends BaseActionType {
      type: 'your-type',
      someOption: string
   }
}

But of course, we need to make ActionType an interface and I'm not sure it's possible at this time. I would love to contribute to this enhancement. Let me know if it's something that makes sense to create.

If something is not clear I can extend my explanation with more examples.

[awhitford]

I am using TypeScript and creating custom actions, and I too ran into this issue. I'd love to see an improvement here so that the TypeScript was cleaner.

Check out this test:

plop/packages/node-plop/types/test.ts

Lines 241 to 255 in e012227

	// use the custom action
	plop.setGenerator("test", {
	prompts: [],
	actions: [
	{
	type: "doTheThing",
	configProp: "available from the config param",
	} as CustomActionConfig<"doTheThing">,
	{
	type: "doTheAsyncThing",
	speed: "slow",
	} as CustomActionConfig<"doTheAsyncThing">,
	],
	});
	}

You can see that there is a CustomActionConfig<"customType"> type. Alas, I don't see a way of importing it. And I don't see their code actually restricting the properties.

Also see #439.