TypeScript Interfaces

.ts

/** Definition for item. */
interface Item {
  key: number;
  value: string;
}

/** The property "items" is an array of type Item. */
interface State {
  newKey: number;
  inputValue: string;
  items: Item[];
}


/** This type's methods return Message objects that are sent to the program's update method and processed by the action methods.*/
interface ActionMethods {
  updateInputValue:(value: string) => State;
  addItem: () => State;
  deleteItem: (key: number) => State;
  useFetchedData: (data: State) => State;
}

/** This is the type for the object of methods used in Msg.match of the update function to trigger the correct actions for the received message. */
interface MessageUnion {
  match: (msg: Message, Object: ActionMethods) => State;
  updateInputValue: (value: string) => State;
  addItem: () => State;
  deleteItem: (key: number) => State;
  useFetchedData: (data: State) => State;
}