# Thunk
Declares a thunk against your model type definition.
# API
Thunk<
Model extends object = {},
Payload = undefined,
Injections = any,
StoreModel extends object = {},
Result = any
>
Model
The model against which the thunk is being defined. You need to provide this so that the actions that will be provided to your thunk are correctly typed.
Payload
The type of the payload that the thunk will receive. You can set this to
undefined
if you do not expect the thunk to receive any payload.Injections
If your store was configured with injections, and you intend to use them within your thunk, then you should provide the type of the injections here.
StoreModel
If you plan on using the
getStoreState
orgetStoreActions
APIs of a thunk then you will need to provide your store model so that the results are correctly typed.Result
If your thunk returns a value then the type of the value should be defined here. The result is returned to the calling point of the dispatch.
# Example
import { Thunk, thunk } from 'easy-peasy';
import { Injections } from './my-store.types.ts';
interface TodosModel {
todos: string[];
savedTodo: Action<TodosModel, string>;
saveTodo: Thunk<TodosModel, string, Injections>;
}
const todosModel: TodosModel = {
todos: [],
savedTodo: action((state, payload) => {
state.todos.push(payload);
}),
saveTodo: thunk(async (actions, payload, { injections }) => {
await injections.todosService.save(payload);
actions.savedTodo(payload);
}),
};
# Declaring a payload as being optional
If you would like to make a payload optional you can use a union with
undefined
.
import { Thunk } from 'easy-peasy';
interface MyModel {
doSomething: Thunk<MyModel, string | undefined>;
}
You can now call the thunk in either of the two ways:
const doSomething = useStoreActions((actions) => actions.doSomething);
doSomething('woot!');
doSomething();