reactjs - Mobx 使用参数计算 (compulatedFn) 和 TypeScript - 这是什么？

Question

以下示例https://mobx.js.org/refguide/computed-decorator.html使用 TypeScript 会引发错误。

// Parameterized computed views:
// Create computed's and store them in a cache
import { observable } from "mobx"
import { computedFn } from "mobx-utils"

class Todos {
  @observable todos = []

  getAllTodosByUser = computedFn(function getAllTodosByUser(userId) {
    return this.todos.filter(todo => todo.user === userId))
  })
}

'this' implicitly has type 'any' because it does not have a type annotation.ts(2683)

An outer value of 'this' is shadowed by this container.

将 tsconfig 的 noImplicitThis 设置为 false 可以解决此问题，但我的目的是将 noImplicitThis 设置为 true。

有什么想法吗？谢谢!

Answer 1

注入(inject) this: Todos 将修复它。 TypeScript 不会提示，并且 this 将被正确键入。请注意，TS 编译器在编译为 JavaScript 时会删除 this 参数。

// Parameterized computed views:
// Create computed's and store them in a cache
import { observable } from "mobx"
import { computedFn } from "mobx-utils"

class Todos {
  @observable todos: ITodo[] = []

  getAllTodosByUser = computedFn(function getAllTodosByUser(this: Todos, userId: ITodo[]) {
    return this.todos.filter(todo => todo.user === userId))
  })
}