feat: add Expo React Native client scaffold

- Expo SDK 54 / React Native 0.81 with expo-router
- Tailscale devcontainer feature for direct device connectivity
- Dev proxy for React Native DevTools access over Tailscale
- EAS build configuration for development/preview/production
- Ona automation for Expo dev server

Co-authored-by: Ona <no-reply@ona.com>
This commit is contained in:
2026-02-19 00:11:31 +00:00
parent f987253e53
commit 3ebb47c5ab
44 changed files with 4177 additions and 8 deletions

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// Reverse proxy that sits in front of Metro so that all requests
// (including those arriving via Tailscale or Ona port-forwarding) reach
// Metro as loopback connections. This satisfies the isLocalSocket check
// in Expo's debug middleware, making /debugger-frontend, /json, and
// /open-debugger accessible from a remote browser.
import type { ServerWebSocket } from "bun"
const PROXY_PORT = parseInt(process.env.PROXY_PORT || "8080", 10)
const METRO_PORT = parseInt(process.env.METRO_PORT || "8081", 10)
const METRO_BASE = `http://127.0.0.1:${METRO_PORT}`
function forwardHeaders(headers: Headers): Headers {
const result = new Headers(headers)
result.delete("origin")
result.delete("referer")
result.set("host", `127.0.0.1:${METRO_PORT}`)
return result
}
interface WsData {
upstream: WebSocket
isDevice: boolean
}
Bun.serve<WsData>({
port: PROXY_PORT,
async fetch(req, server) {
const url = new URL(req.url)
// WebSocket upgrade — bridge to Metro's ws endpoint
if (req.headers.get("upgrade")?.toLowerCase() === "websocket") {
const wsUrl = `ws://127.0.0.1:${METRO_PORT}${url.pathname}${url.search}`
const upstream = new WebSocket(wsUrl)
// Wait for upstream to connect before upgrading the client
try {
await new Promise<void>((resolve, reject) => {
upstream.addEventListener("open", () => resolve())
upstream.addEventListener("error", () => reject(new Error("upstream ws failed")))
})
} catch {
return new Response("Upstream WebSocket unavailable", { status: 502 })
}
const isDevice = url.pathname.startsWith("/inspector/device")
const ok = server.upgrade(req, { data: { upstream, isDevice } })
if (!ok) {
upstream.close()
return new Response("WebSocket upgrade failed", { status: 500 })
}
return undefined
}
// HTTP proxy
const upstream = `${METRO_BASE}${url.pathname}${url.search}`
const res = await fetch(upstream, {
method: req.method,
headers: forwardHeaders(req.headers),
body: req.body,
redirect: "manual",
})
return new Response(res.body, {
status: res.status,
statusText: res.statusText,
headers: res.headers,
})
},
websocket: {
message(ws: ServerWebSocket<WsData>, msg) {
ws.data.upstream.send(msg)
},
open(ws: ServerWebSocket<WsData>) {
const { upstream } = ws.data
upstream.addEventListener("message", (ev) => {
if (typeof ev.data === "string") {
ws.send(ev.data)
} else if (ev.data instanceof ArrayBuffer) {
ws.sendBinary(new Uint8Array(ev.data))
}
})
upstream.addEventListener("close", () => ws.close())
upstream.addEventListener("error", () => ws.close())
// Print debugger URL shortly after a device connects,
// giving Metro time to register the target.
if (ws.data.isDevice) {
setTimeout(() => printDebuggerUrl(), 1000)
}
},
close(ws: ServerWebSocket<WsData>) {
ws.data.upstream.close()
},
},
})
const tsIp = await Bun.$`tailscale ip -4`.text().then((s) => s.trim())
async function printDebuggerUrl() {
const base = `http://${tsIp}:${PROXY_PORT}`
const res = await fetch(`${METRO_BASE}/json`)
if (!res.ok) return
interface DebugTarget {
webSocketDebuggerUrl: string
reactNative?: {
capabilities?: { prefersFuseboxFrontend?: boolean }
}
}
const targets: DebugTarget[] = await res.json()
const target = targets.find((t) => t.reactNative?.capabilities?.prefersFuseboxFrontend)
if (!target) return
const wsPath = target.webSocketDebuggerUrl
.replace(/^ws:\/\//, "")
.replace(`127.0.0.1:${METRO_PORT}`, `${tsIp}:${PROXY_PORT}`)
console.log(
`\n React Native DevTools:\n ${base}/debugger-frontend/rn_fusebox.html?ws=${encodeURIComponent(wsPath)}&sources.hide_add_folder=true&unstable_enableNetworkPanel=true\n`,
)
}
console.log(`[proxy] listening on :${PROXY_PORT}, forwarding to 127.0.0.1:${METRO_PORT}`)

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// Opens React Native DevTools in Chrome, connected to the first
// available Hermes debug target. Requires Metro + proxy to be running.
import { $ } from "bun"
const PROXY_PORT = process.env.PROXY_PORT || "8080"
const METRO_PORT = process.env.METRO_PORT || "8081"
const tsIp = (await $`tailscale ip -4`.text()).trim()
const base = `http://${tsIp}:${PROXY_PORT}`
interface DebugTarget {
devtoolsFrontendUrl: string
webSocketDebuggerUrl: string
reactNative?: {
capabilities?: {
prefersFuseboxFrontend?: boolean
}
}
}
const res = await fetch(`${base}/json`)
if (!res.ok) {
console.error("Failed to fetch /json — is Metro running?")
process.exit(1)
}
const targets: DebugTarget[] = await res.json()
const target = targets.find((t) => t.reactNative?.capabilities?.prefersFuseboxFrontend)
if (!target) {
console.error("No debug target found. Is the app connected?")
process.exit(1)
}
const wsUrl = target.webSocketDebuggerUrl
.replace(/^ws:\/\//, "")
.replace(`127.0.0.1:${METRO_PORT}`, `${tsIp}:${PROXY_PORT}`)
const url = `${base}/debugger-frontend/rn_fusebox.html?ws=${encodeURIComponent(wsUrl)}&sources.hide_add_folder=true&unstable_enableNetworkPanel=true`
console.log(url)
// Open in Chrome app mode if on macOS
try {
await $`open -a "Google Chrome" --args --app=${url}`.quiet()
} catch {
try {
await $`xdg-open ${url}`.quiet()
} catch {
console.log("Open the URL above in Chrome.")
}
}

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#!/usr/bin/env node
/**
* This script is used to reset the project to a blank state.
* It deletes or moves the /app, /components, /hooks, /scripts, and /constants directories to /app-example based on user input and creates a new /app directory with an index.tsx and _layout.tsx file.
* You can remove the `reset-project` script from package.json and safely delete this file after running it.
*/
const fs = require("fs")
const path = require("path")
const readline = require("readline")
const root = process.cwd()
const oldDirs = ["app", "components", "hooks", "constants", "scripts"]
const exampleDir = "app-example"
const newAppDir = "app"
const exampleDirPath = path.join(root, exampleDir)
const indexContent = `import { Text, View } from "react-native";
export default function Index() {
return (
<View
style={{
flex: 1,
justifyContent: "center",
alignItems: "center",
}}
>
<Text>Edit app/index.tsx to edit this screen.</Text>
</View>
);
}
`
const layoutContent = `import { Stack } from "expo-router";
export default function RootLayout() {
return <Stack />;
}
`
const rl = readline.createInterface({
input: process.stdin,
output: process.stdout,
})
const moveDirectories = async (userInput) => {
try {
if (userInput === "y") {
// Create the app-example directory
await fs.promises.mkdir(exampleDirPath, { recursive: true })
console.log(`📁 /${exampleDir} directory created.`)
}
// Move old directories to new app-example directory or delete them
for (const dir of oldDirs) {
const oldDirPath = path.join(root, dir)
if (fs.existsSync(oldDirPath)) {
if (userInput === "y") {
const newDirPath = path.join(root, exampleDir, dir)
await fs.promises.rename(oldDirPath, newDirPath)
console.log(`➡️ /${dir} moved to /${exampleDir}/${dir}.`)
} else {
await fs.promises.rm(oldDirPath, { recursive: true, force: true })
console.log(`❌ /${dir} deleted.`)
}
} else {
console.log(`➡️ /${dir} does not exist, skipping.`)
}
}
// Create new /app directory
const newAppDirPath = path.join(root, newAppDir)
await fs.promises.mkdir(newAppDirPath, { recursive: true })
console.log("\n📁 New /app directory created.")
// Create index.tsx
const indexPath = path.join(newAppDirPath, "index.tsx")
await fs.promises.writeFile(indexPath, indexContent)
console.log("📄 app/index.tsx created.")
// Create _layout.tsx
const layoutPath = path.join(newAppDirPath, "_layout.tsx")
await fs.promises.writeFile(layoutPath, layoutContent)
console.log("📄 app/_layout.tsx created.")
console.log("\n✅ Project reset complete. Next steps:")
console.log(
`1. Run \`npx expo start\` to start a development server.\n2. Edit app/index.tsx to edit the main screen.${
userInput === "y"
? `\n3. Delete the /${exampleDir} directory when you're done referencing it.`
: ""
}`,
)
} catch (error) {
console.error(`❌ Error during script execution: ${error.message}`)
}
}
rl.question(
"Do you want to move existing files to /app-example instead of deleting them? (Y/n): ",
(answer) => {
const userInput = answer.trim().toLowerCase() || "y"
if (userInput === "y" || userInput === "n") {
moveDirectories(userInput).finally(() => rl.close())
} else {
console.log("❌ Invalid input. Please enter 'Y' or 'N'.")
rl.close()
}
},
)

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#!/usr/bin/env bash
set -euo pipefail
PROXY_PORT=8080
METRO_PORT=8081
# Start a reverse proxy so Metro sees all requests as loopback.
# This makes debugger endpoints (/debugger-frontend, /json, /open-debugger)
# accessible through the Tailscale IP.
PROXY_PORT=$PROXY_PORT METRO_PORT=$METRO_PORT bun run scripts/dev-proxy.ts &
PROXY_PID=$!
trap "kill $PROXY_PID 2>/dev/null" EXIT
EXPO_PACKAGER_PROXY_URL=http://$(tailscale ip -4):$PROXY_PORT bunx expo start --localhost -p $METRO_PORT