vue3-yuanma/test-dts/ref.test-d.ts
2020-04-22 11:54:54 -04:00

87 lines
2.0 KiB
TypeScript

import { expectType } from 'tsd'
import { Ref, ref, isRef, unref } from './index'
function plainType(arg: number | Ref<number>) {
// ref coercing
const coerced = ref(arg)
expectType<Ref<number>>(coerced)
// isRef as type guard
if (isRef(arg)) {
expectType<Ref<number>>(arg)
}
// ref unwrapping
expectType<number>(unref(arg))
// ref inner type should be unwrapped
const nestedRef = ref({
foo: ref(1)
})
expectType<Ref<{ foo: number }>>(nestedRef)
expectType<{ foo: number }>(nestedRef.value)
// ref boolean
const falseRef = ref(false)
expectType<Ref<boolean>>(falseRef)
expectType<boolean>(falseRef.value)
// ref true
const trueRef = ref<true>(true)
expectType<Ref<true>>(trueRef)
expectType<true>(trueRef.value)
// tuple
expectType<[number, string]>(unref(ref([1, '1'])))
interface IteratorFoo {
[Symbol.iterator]: any
}
// with symbol
expectType<Ref<IteratorFoo | null | undefined>>(
ref<IteratorFoo | null | undefined>()
)
}
plainType(1)
function bailType(arg: HTMLElement | Ref<HTMLElement>) {
// ref coercing
const coerced = ref(arg)
expectType<Ref<HTMLElement>>(coerced)
// isRef as type guard
if (isRef(arg)) {
expectType<Ref<HTMLElement>>(arg)
}
// ref unwrapping
expectType<HTMLElement>(unref(arg))
// ref inner type should be unwrapped
const nestedRef = ref({ foo: ref(document.createElement('DIV')) })
expectType<Ref<{ foo: HTMLElement }>>(nestedRef)
expectType<{ foo: HTMLElement }>(nestedRef.value)
}
const el = document.createElement('DIV')
bailType(el)
function withSymbol() {
const customSymbol = Symbol()
const obj = {
[Symbol.asyncIterator]: { a: 1 },
[Symbol.unscopables]: { b: '1' },
[customSymbol]: { c: [1, 2, 3] }
}
const objRef = ref(obj)
expectType<{ a: number }>(objRef.value[Symbol.asyncIterator])
expectType<{ b: string }>(objRef.value[Symbol.unscopables])
expectType<{ c: Array<number> }>(objRef.value[customSymbol])
}
withSymbol()