Sheraff

// node repro.js <gap in ms>
import { readFileSync, writeFileSync } from 'node:fs'
import { setTimeout as sleep } from 'node:timers/promises'
import { createServer } from 'vite'

const gap = Number(process.argv[2])
writeFileSync('root/a.js', 'export default 0\n')
const server = await createServer({ root: 'root', configFile: false, server: { middlewareMode: true, hmr: false } })
await new Promise((resolve) => server.watcher.once('ready', resolve))
server.watcher.on('change', (file) => console.log('change:', readFileSync(file, 'utf8').trim()))

Sheraff

Proposed fix for this.load() after HMR

Reproduction: with Vite's bundled dev mode, this.load() returns source initially but returns null for a new dependency after HMR.

This patch has not been compiled or tested. It has been formatted, checked for whitespace errors, and checked that it applies to the commit below.

Why it fails

Sheraff

import { useSyncExternalStore, useCallback } from "react";

/**
 * Use for getting the value of given `key` in `localStorage`, or setting it.
 *
 * @param key - `localStorage` key we want to get its value, or change it
 * @example
 *
 * ```tsx
 * const [hello, setHello] = useLocalStorageKey("hello");

Sheraff

interface ReadonlySignal<T> {
	invalidate(): void
	readonly value: T
}
interface WritableSignal<T> {
	value: T
}

let running: ReadonlySignal<any> | null = null

Sheraff

function getSupportedLocales(): string[] {
	const candidates: string[] = []

	const letters = Array.from({ length: 26 }, (_, i) => String.fromCharCode(65 + i))
	for (const a of letters) {
		for (const b of letters) {
			candidates.push(a + b)
			for (const c of letters) {
				candidates.push(a + b + c)
			}

Sheraff

export type LRUCache<K, V> = {
  get: (key: K) => V | undefined
  set: (key: K, value: V) => void
}
export function createLRUCache<K, V>(max: number): LRUCache<K, V> {
  type Node = { prev?: Node; next?: Node; key: K, value: V }
  const cache = new Map<K, Node>()
  let oldest: Node | undefined
  let newest: Node | undefined
  const touch = (entry: Node) => {

Sheraff

class LRUMap<TKey, TValue> extends Map<TKey, TValue> {
  constructor(max: number) {
    super()
    const get = this.get.bind(this)
    const set = this.set.bind(this)
    this.get = (key: TKey) => {
      const item = get(key)
      if (item !== undefined) {
        // refresh key
        this.delete(key)

Sheraff

//@ts-check

const Component = ({ names }: { names: [string] }) => (
   <p>{names[0]}</p>
)

export default function App() {
   return <div>Hello world</div>
}

Sheraff

import { Suspense } from "react";

type CacheItem<T> = {
	keys: any[]
	promise: Promise<T>
	error?: unknown
	response?: T
}
const cache: CacheItem<any>[] = []

Sheraff

const ACTIVATIONS = [
	/*'identity': */x => x,
	/*'abs': */		x => Math.abs(x),
	/*'clamped': */	x => Math.min(1, Math.max(-1, x)),
	/*'cube': */	x => Math.pow(x, 3),
	/*'exp': */		x => Math.exp(x),
	/*'gauss': */	x => x,
	/*'hat': */		x => Math.max(0, x < 0 ? 1 + x : 1 - x),
	/*'inv': */		x => 1 / x,
	/*'log': */		x => Math.log(x),