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/**
* We extend `Date` during builds and revalidates to ensure that prerenders don't observe the clock as a source of IO
* When cacheComponents is enabled. The current time is a form of IO even though it resolves synchronously. When cacheComponents is
* enabled we need to ensure that clock time is excluded from prerenders unless it is cached.
*
* There is tension here because time is used for both output and introspection. While arbitrary we intend to reserve
* `Date` for output use cases and `performance` for introspection use cases. If you want to measure
* how long something takes use `performance.timeOrigin` and `performance.now()` rather than `Date.now()` for instance.
*
* The extensions here never error nor alter the underlying Date objects, strings, and numbers created and thus should be transparent to callers.
*/
import { io } from './utils'
function createNow(originalNow: typeof Date.now) {
return {
now: function now() {
io('`Date.now()`', 'time')
return originalNow()
},
}['now'.slice() as 'now'].bind(null)
}
function createDate(originalConstructor: typeof Date): typeof Date {
const properties = Object.getOwnPropertyDescriptors(originalConstructor)
properties.now.value = createNow(originalConstructor.now)
const apply = Reflect.apply
const construct = Reflect.construct
const newConstructor = Object.defineProperties(
// Ideally this should not minify the name.
function Date() {
if (new.target === undefined) {
io('`Date()`', 'time')
return apply(originalConstructor, undefined, arguments)
}
if (arguments.length === 0) {
io('`new Date()`', 'time')
}
return construct(originalConstructor, arguments, new.target)
},
properties
)
Object.defineProperty(originalConstructor.prototype, 'constructor', {
value: newConstructor,
})
return newConstructor as typeof Date
}
try {
// eslint-disable-next-line no-native-reassign
Date = createDate(Date)
} catch {
console.error(
'Failed to install `Date` class extension. When using `experimental.cacheComponents`, APIs that read the current time will not correctly trigger dynamic behavior.'
)
}
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