7 files changed, 681 insertions, 0 deletions
diff --git a/packages/upgrade/src/actions/context.ts b/packages/upgrade/src/actions/context.ts
new file mode 100644
index 000000000..d5a5778d4
--- /dev/null
+++ b/packages/upgrade/src/actions/context.ts
@@ -0,0 +1,56 @@
+import { prompt } from '@astrojs/cli-kit';
+import arg from 'arg';
+import { pathToFileURL } from 'node:url';
+import detectPackageManager from 'which-pm-runs';
+
+export interface Context {
+	help: boolean;
+	prompt: typeof prompt;
+	version: string;
+	dryRun?: boolean;
+	cwd: URL;
+	stdin?: typeof process.stdin;
+	stdout?: typeof process.stdout;
+	packageManager: string;
+	packages: PackageInfo[];
+	exit(code: number): never;
+}
+
+export interface PackageInfo {
+	name: string;
+	currentVersion: string;
+	targetVersion: string;
+	tag?: string;
+	isDevDependency?: boolean;
+	isMajor?: boolean;
+	changelogURL?: string;
+	changelogTitle?: string;
+}
+
+export async function getContext(argv: string[]): Promise<Context> {
+	const flags = arg(
+		{
+			'--dry-run': Boolean,
+			'--help': Boolean,
+
+			'-h': '--help',
+		},
+		{ argv, permissive: true }
+	)
+
+	const packageManager = detectPackageManager()?.name ?? 'npm';
+	const { _: [version = 'latest'] = [], '--help': help = false, '--dry-run': dryRun } = flags;
+
+	return {
+		help,
+		prompt,
+		packageManager,
+		packages: [],
+		cwd: new URL(pathToFileURL(process.cwd()) + '/'),
+		dryRun,
+		version,
+		exit(code) {
+			process.exit(code);
+		},
+	} satisfies Context
+}
diff --git a/packages/upgrade/src/actions/help.ts b/packages/upgrade/src/actions/help.ts
new file mode 100644
index 000000000..d61abc71e
--- /dev/null
+++ b/packages/upgrade/src/actions/help.ts
@@ -0,0 +1,15 @@
+import { printHelp } from '../messages.js';
+
+export function help() {
+	printHelp({
+		commandName: '@astrojs/upgrade',
+		usage: '[version] [...flags]',
+		headline: 'Upgrade Astro dependencies.',
+		tables: {
+			Flags: [
+				['--help (-h)', 'See all available flags.'],
+				['--dry-run', 'Walk through steps without executing.']
+			],
+		},
+	});
+}
diff --git a/packages/upgrade/src/actions/install.ts b/packages/upgrade/src/actions/install.ts
new file mode 100644
index 000000000..4696d5eb5
--- /dev/null
+++ b/packages/upgrade/src/actions/install.ts
@@ -0,0 +1,138 @@
+import type { Context, PackageInfo } from './context.js';
+
+import fs from 'node:fs';
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+import { color, say } from '@astrojs/cli-kit';
+import { pluralize, celebrations, done, error, info, log, spinner, success, upgrade, banner, title, changelog, warn, bye, newline } from '../messages.js';
+import { shell } from '../shell.js';
+import { random, sleep } from '@astrojs/cli-kit/utils';
+import { satisfies } from 'semver';
+
+export async function install(
+	ctx: Pick<Context, 'version' | 'packages' | 'packageManager' | 'prompt' | 'dryRun' | 'exit' | 'cwd'>
+) {
+	await banner();
+	newline();
+	const { current, dependencies, devDependencies } = filterPackages(ctx);
+	const toInstall = [...dependencies, ...devDependencies].sort(sortPackages);
+	for (const packageInfo of current.sort(sortPackages)) {
+		const tag = /^\d/.test(packageInfo.targetVersion) ? packageInfo.targetVersion : packageInfo.targetVersion.slice(1)
+		await info(`${packageInfo.name}`, `is up to date on`, `v${tag}`)
+		await sleep(random(50, 150));
+	}
+	if (toInstall.length === 0 && !ctx.dryRun) {
+		newline()
+		await success(random(celebrations), random(done));
+		return;
+	}
+	const majors: PackageInfo[] = []
+	for (const packageInfo of toInstall) {
+		const word = ctx.dryRun ? 'can' : 'will';
+		await upgrade(packageInfo, `${word} be updated to`)
+		if (packageInfo.isMajor) {
+			majors.push(packageInfo)
+		}
+	}
+	if (majors.length > 0) {
+		const { proceed } = await ctx.prompt({
+			name: 'proceed',
+			type: 'confirm',
+			label: title('wait'),
+			message: `${pluralize(['One package has', 'Some packages have'], majors.length)} breaking changes. Continue?`,
+			initial: true,
+		});
+		if (!proceed) {
+			return ctx.exit(0);
+		}
+		
+		newline();
+		
+		await warn('check', `Be sure to follow the ${pluralize('CHANGELOG', majors.length)}.`);
+		for (const pkg of majors.sort(sortPackages)) {
+			await changelog(pkg.name, pkg.changelogTitle!, pkg.changelogURL!);
+		}
+	}
+
+	newline()
+	if (ctx.dryRun) {
+		await info('--dry-run', `Skipping dependency installation`);
+	} else {
+		await runInstallCommand(ctx, dependencies, devDependencies);
+	}
+}
+
+function filterPackages(ctx: Pick<Context, 'packages'>) {
+	const current: PackageInfo[] = [];
+	const dependencies: PackageInfo[] = [];
+	const devDependencies: PackageInfo[] = [];
+	for (const packageInfo of ctx.packages) {
+		const { currentVersion, targetVersion, isDevDependency } = packageInfo;
+		// Remove prefix from `currentVersion` before comparing
+		if (currentVersion.replace(/^\D+/, '') === targetVersion) {
+			current.push(packageInfo);
+		} else {
+			const arr = isDevDependency ? devDependencies : dependencies;
+			arr.push(packageInfo);
+		}
+	}
+	return { current, dependencies, devDependencies }
+}
+
+/**
+  * An `Array#sort` comparator function to normalize how packages are displayed.
+  * This only changes how the packages are displayed in the CLI, it is not persisted to `package.json`.
+  */
+function sortPackages(a: PackageInfo, b: PackageInfo): number {
+	if (a.isMajor && !b.isMajor) return 1;
+	if (b.isMajor && !a.isMajor) return -1;
+	if (a.name === 'astro') return -1;
+	if (b.name === 'astro') return 1;
+	if (a.name.startsWith('@astrojs') && !b.name.startsWith('@astrojs')) return -1;
+	if (b.name.startsWith('@astrojs') && !a.name.startsWith('@astrojs')) return 1;
+	return a.name.localeCompare(b.name);
+}
+
+async function runInstallCommand(ctx: Pick<Context, 'cwd' | 'packageManager' | 'exit'>, dependencies: PackageInfo[], devDependencies: PackageInfo[]) {
+	const cwd = fileURLToPath(ctx.cwd);
+	if (ctx.packageManager === 'yarn') await ensureYarnLock({ cwd });
+
+	await spinner({
+		start: `Installing dependencies with ${ctx.packageManager}...`,
+		end: `Installed dependencies!`,
+		while: async () => {
+			try {
+				if (dependencies.length > 0) {
+					await shell(ctx.packageManager, ['install', ...dependencies.map(({ name, targetVersion }) => `${name}@${(targetVersion).replace(/^\^/, '')}`)], { cwd, timeout: 90_000, stdio: 'ignore' })
+				}
+				if (devDependencies.length > 0) {
+					await shell(ctx.packageManager, ['install', '--save-dev', ...devDependencies.map(({ name, targetVersion }) => `${name}@${(targetVersion).replace(/^\^/, '')}`)], { cwd, timeout: 90_000, stdio: 'ignore' })
+				}
+			} catch {
+				const packages = [...dependencies, ...devDependencies].map(({ name, targetVersion }) => `${name}@${targetVersion}`).join(' ')
+				newline();
+				error(
+					'error',
+					`Dependencies failed to install, please run the following command manually:\n${color.bold(`${ctx.packageManager} install ${packages}`)}`
+				);
+				return ctx.exit(1);
+			}
+		},
+	});
+
+	await say([`${random(celebrations)} ${random(done)}`, random(bye)], { clear: false });
+}
+
+/**
+ * Yarn Berry (PnP) versions will throw an error if there isn't an existing `yarn.lock` file
+ * If a `yarn.lock` file doesn't exist, this function writes an empty `yarn.lock` one.
+ * Unfortunately this hack is required to run `yarn install`.
+ *
+ * The empty `yarn.lock` file is immediately overwritten by the installation process.
+ * See https://github.com/withastro/astro/pull/8028
+ */
+async function ensureYarnLock({ cwd }: { cwd: string }) {
+	const yarnLock = path.join(cwd, 'yarn.lock');
+	if (fs.existsSync(yarnLock)) return;
+	return fs.promises.writeFile(yarnLock, '', { encoding: 'utf-8' });
+}
diff --git a/packages/upgrade/src/actions/verify.ts b/packages/upgrade/src/actions/verify.ts
new file mode 100644
index 000000000..be86c5344
--- /dev/null
+++ b/packages/upgrade/src/actions/verify.ts
@@ -0,0 +1,165 @@
+import type { Context, PackageInfo } from './context.js';
+
+import dns from 'node:dns/promises';
+import { existsSync } from 'node:fs';
+import { readFile } from 'node:fs/promises';
+import { color } from '@astrojs/cli-kit';
+import { bannerAbort, error, getRegistry, info, log, newline } from '../messages.js';
+import semverDiff from 'semver/functions/diff.js';
+import semverCoerce from 'semver/functions/coerce.js';
+import semverParse from 'semver/functions/parse.js';
+
+
+export async function verify(
+	ctx: Pick<Context, 'version' | 'packages' | 'cwd' | 'dryRun' | 'exit'>
+) {
+	const registry = await getRegistry();
+
+	if (!ctx.dryRun) {
+		const online = await isOnline(registry);
+		if (!online) {
+			bannerAbort();
+			newline();
+			error('error', `Unable to connect to the internet.`);
+			ctx.exit(1);
+		}
+	}
+
+	await verifyAstroProject(ctx);
+
+	const ok = await verifyVersions(ctx, registry);
+	if (!ok) {
+		bannerAbort();
+		newline();
+		error('error', `Version ${color.reset(ctx.version)} ${color.dim('could not be found!')}`);
+		await info('check', 'https://github.com/withastro/astro/releases');
+		ctx.exit(1);
+	}
+}
+
+function isOnline(registry: string): Promise<boolean> {
+	const { host } = new URL(registry);
+	return dns.lookup(host).then(
+		() => true,
+		() => false
+	);
+}
+
+function safeJSONParse(value: string) {
+	try {
+		return JSON.parse(value);
+	} catch {}
+	return {}
+}
+
+async function verifyAstroProject(ctx: Pick<Context, 'cwd' | 'version' | 'packages'>) {
+	const packageJson = new URL('./package.json', ctx.cwd);
+    if (!existsSync(packageJson)) return false;
+	const contents = await readFile(packageJson, { encoding: 'utf-8' });
+	if (!contents.includes('astro')) return false;
+
+	const { dependencies = {}, devDependencies = {} } = safeJSONParse(contents)
+	if (dependencies['astro'] === undefined && devDependencies['astro'] === undefined) return false;
+	
+	// Side-effect! Persist dependency info to the shared context
+	collectPackageInfo(ctx, dependencies, devDependencies);
+	
+	return true;
+}
+
+function isAstroPackage(name: string) {
+	return name === 'astro' || name.startsWith('@astrojs/');
+}
+
+function collectPackageInfo(ctx: Pick<Context, 'version' | 'packages'>, dependencies: Record<string, string>, devDependencies: Record<string, string>) {
+	for (const [name, currentVersion] of Object.entries(dependencies)) {
+		if (!isAstroPackage(name)) continue;
+		ctx.packages.push({
+			name,
+			currentVersion,
+			targetVersion: ctx.version,
+		})
+	}
+	for (const [name, currentVersion] of Object.entries(devDependencies)) {
+		if (!isAstroPackage(name)) continue;
+		ctx.packages.push({
+			name,
+			currentVersion,
+			targetVersion: ctx.version,
+			isDevDependency: true
+		})
+	}
+}
+
+async function verifyVersions(ctx: Pick<Context, 'version' | 'packages' | 'exit'>, registry: string) {
+	const tasks: Promise<void>[] = [];
+	for (const packageInfo of ctx.packages) {
+		tasks.push(resolveTargetVersion(packageInfo, registry));
+	}
+	try {
+		await Promise.all(tasks);
+	} catch {
+		return false;
+	}
+	for (const packageInfo of ctx.packages) {
+		if (!packageInfo.targetVersion) {
+			return false;
+		}
+	}
+	return true;
+}
+
+async function resolveTargetVersion(packageInfo: PackageInfo, registry: string): Promise<void> {
+	const packageMetadata = await fetch(`${registry}/${packageInfo.name}`, { headers: { accept: 'application/vnd.npm.install-v1+json' }});
+	if (packageMetadata.status >= 400) {
+		throw new Error(`Unable to resolve "${packageInfo.name}"`);
+	}
+	const { "dist-tags": distTags } = await packageMetadata.json();
+	let version = distTags[packageInfo.targetVersion];
+	if (version) {
+		packageInfo.tag = packageInfo.targetVersion;
+		packageInfo.targetVersion = version;
+	} else {
+		packageInfo.targetVersion = 'latest';
+		version = distTags.latest;
+	}
+	if (packageInfo.currentVersion === version) {
+		return;
+	}
+	const prefix = packageInfo.targetVersion === 'latest' ? '^' : '';
+	packageInfo.targetVersion = `${prefix}${version}`;
+	const fromVersion = semverCoerce(packageInfo.currentVersion)!;
+	const toVersion = semverParse(version)!;
+	const bump = semverDiff(fromVersion, toVersion);
+	if ((bump === 'major' && toVersion.prerelease.length === 0) || bump === 'premajor') {
+		packageInfo.isMajor = true;
+		if (packageInfo.name === 'astro') {
+			const upgradeGuide = `https://docs.astro.build/en/guides/upgrade-to/v${toVersion.major}/`;
+			const docsRes = await fetch(upgradeGuide);
+			// OK if this request fails, it's probably a prerelease without a public migration guide.
+			// In that case, we should fallback to the CHANGELOG check below.
+			if (docsRes.status === 200) {
+				packageInfo.changelogURL = upgradeGuide;
+				packageInfo.changelogTitle = `Upgrade to Astro v${toVersion.major}`;
+				return;
+			}
+		}
+		const latestMetadata = await fetch(`${registry}/${packageInfo.name}/latest`);
+		if (latestMetadata.status >= 400) {
+			throw new Error(`Unable to resolve "${packageInfo.name}"`);
+		}
+		const { repository } = await latestMetadata.json();
+		const branch = bump === 'premajor' ? 'next' : 'main';
+		packageInfo.changelogURL = extractChangelogURLFromRepository(repository, version, branch);
+		packageInfo.changelogTitle = 'CHANGELOG';
+	} else {
+		// Dependency updates should not include the specific dist-tag
+		// since they are just for compatability
+		packageInfo.tag = undefined;
+	}
+}
+
+function extractChangelogURLFromRepository(repository: Record<string, string>, version: string, branch = 'main') {
+	return repository.url.replace('git+', '').replace('.git', '') + `/blob/${branch}/` + repository.directory + '/CHANGELOG.md#' + version.replace(/\./g, '')
+}
+
diff --git a/packages/upgrade/src/index.ts b/packages/upgrade/src/index.ts
new file mode 100644
index 000000000..ab216ad56
--- /dev/null
+++ b/packages/upgrade/src/index.ts
@@ -0,0 +1,40 @@
+import { getContext } from './actions/context.js';
+
+import { install } from './actions/install.js';
+import { help } from './actions/help.js';
+import { verify } from './actions/verify.js';
+import { setStdout } from './messages.js';
+
+const exit = () => process.exit(0);
+process.on('SIGINT', exit);
+process.on('SIGTERM', exit);
+
+export async function main() {
+	// NOTE: In the v7.x version of npm, the default behavior of `npm init` was changed
+	// to no longer require `--` to pass args and instead pass `--` directly to us. This
+	// broke our arg parser, since `--` is a special kind of flag. Filtering for `--` here
+	// fixes the issue so that create-astro now works on all npm versions.
+	const cleanArgv = process.argv.slice(2).filter((arg) => arg !== '--');
+	const ctx = await getContext(cleanArgv);
+	if (ctx.help) {
+		help();
+		return;
+	}
+
+	const steps = [
+		verify,
+		install,
+	];
+
+	for (const step of steps) {
+		await step(ctx);
+	}
+	process.exit(0);
+}
+
+export {
+	install,
+	getContext,
+	setStdout,
+	verify,
+};
diff --git a/packages/upgrade/src/messages.ts b/packages/upgrade/src/messages.ts
new file mode 100644
index 000000000..d043db310
--- /dev/null
+++ b/packages/upgrade/src/messages.ts
@@ -0,0 +1,207 @@
+/* eslint no-console: 'off' */
+import type { PackageInfo } from './actions/context.js';
+import { color, label, spinner as load } from '@astrojs/cli-kit';
+import { align } from '@astrojs/cli-kit/utils';
+import detectPackageManager from 'which-pm-runs';
+import { shell } from './shell.js';
+import semverParse from 'semver/functions/parse.js';
+import terminalLink from 'terminal-link';
+
+// Users might lack access to the global npm registry, this function
+// checks the user's project type and will return the proper npm registry
+//
+// A copy of this function also exists in the astro package
+export async function getRegistry(): Promise<string> {
+	const packageManager = detectPackageManager()?.name || 'npm';
+	try {
+		const { stdout } = await shell(packageManager, ['config', 'get', 'registry']);
+		return stdout?.trim()?.replace(/\/$/, '') || 'https://registry.npmjs.org';
+	} catch (e) {
+		return 'https://registry.npmjs.org';
+	}
+}
+
+let stdout = process.stdout;
+/** @internal Used to mock `process.stdout.write` for testing purposes */
+export function setStdout(writable: typeof process.stdout) {
+	stdout = writable;
+}
+
+export async function spinner(args: {
+	start: string;
+	end: string;
+	while: (...args: any) => Promise<any>;
+}) {
+	await load(args, { stdout });
+}
+
+export function pluralize(word: string | [string, string], n: number) {
+	const [singular, plural] = Array.isArray(word) ? word : [word, word + 's'];
+	if (n === 1) return singular;
+	return plural;
+}
+
+export const celebrations = [
+	'Beautiful.',
+	'Excellent!',
+	'Sweet!',
+	'Nice!',
+	'Huzzah!',
+	'Success.',
+	'Nice.',
+	'Wonderful.',
+	'Lovely!',
+	'Lookin\' good.',
+	'Awesome.'
+]
+
+export const done = [
+	'You\'re on the latest and greatest.',
+	'Your integrations are up-to-date.',
+	'Everything is current.',
+	'Everything is up to date.',
+	'Integrations are all up to date.',
+	'Everything is on the latest and greatest.',
+	'Integrations are up to date.',
+]
+
+export const bye = [
+	'Thanks for using Astro!',
+	'Have fun building!',
+	'Take it easy, astronaut!',
+	'Can\'t wait to see what you build.',
+	'Good luck out there.',
+	'See you around, astronaut.',
+]
+
+export const log = (message: string) => stdout.write(message + '\n');
+
+export const newline = () => stdout.write('\n');
+
+export const banner = async () =>
+	log(
+		`\n${label('astro', color.bgGreen, color.black)}  ${color.bold('Integration upgrade in progress.')}`
+	);
+
+export const bannerAbort = () =>
+	log(`\n${label('astro', color.bgRed)} ${color.bold('Integration upgrade aborted.')}`);
+
+export const warn = async (prefix: string, text: string) => {
+	log(`${label(prefix, color.bgCyan, color.black)}  ${text}`);
+}
+
+export const info = async (prefix: string, text: string, version = '') => {
+	const length = 11 + prefix.length + text.length + version?.length;
+	const symbol = '◼';
+	if (length > stdout.columns) {
+		log(`${' '.repeat(5)} ${color.cyan(symbol)}  ${prefix}`);
+		log(`${' '.repeat(9)}${color.dim(text)} ${color.reset(version)}`);
+	} else {
+		log(`${' '.repeat(5)} ${color.cyan(symbol)}  ${prefix} ${color.dim(text)} ${color.reset(version)}`);
+	}
+}
+export const upgrade = async (packageInfo: PackageInfo, text: string) => {
+	const { name, isMajor = false, targetVersion } = packageInfo;
+	
+	const bg = isMajor ? (v: string) => color.bgYellow(color.black(` ${v} `)) : color.green;
+	const style = isMajor ? color.yellow : color.green;
+	const symbol = isMajor ? '▲' : '●';
+	const toVersion = semverParse(targetVersion)!;
+	const version = `v${toVersion.version}`;
+
+	const length = 12 + name.length + text.length + version.length;
+	if (length > stdout.columns) {
+		log(`${' '.repeat(5)} ${style(symbol)}  ${name}`);
+		log(`${' '.repeat(9)}${color.dim(text)} ${bg(version)}`);
+	} else {
+		log(`${' '.repeat(5)} ${style(symbol)}  ${name} ${color.dim(text)} ${bg(version)}`);
+	}
+}
+
+export const title = (text: string) => align(label(text, color.bgYellow, color.black), 'end', 7) + ' ';
+
+export const success = async (prefix: string, text: string) => {
+	const length = 10 + prefix.length + text.length;
+	if (length > stdout.columns) {
+		log(`${' '.repeat(5)} ${color.green("✔")}  ${prefix}`);
+		log(`${' '.repeat(9)}${color.dim(text)}`);
+	} else {
+		log(`${' '.repeat(5)} ${color.green("✔")}  ${prefix} ${color.dim(text)}`);
+	}
+};
+
+export const error = async (prefix: string, text: string) => {
+	if (stdout.columns < 80) {
+		log(`${' '.repeat(5)} ${color.red('▲')}  ${color.red(prefix)}`);
+		log(`${' '.repeat(9)}${color.dim(text)}`);
+	} else {
+		log(`${' '.repeat(5)} ${color.red('▲')}  ${color.red(prefix)} ${color.dim(text)}`);
+	}
+};
+
+export const changelog = async (name: string, text: string, url: string) => {
+	const link = terminalLink(text, url, { fallback: () => url });
+	const linkLength = terminalLink.isSupported ? text.length : url.length;
+	const symbol = ' ';
+
+	const length = 12 + name.length + linkLength;
+	if (length > stdout.columns) {
+		log(`${' '.repeat(5)} ${symbol}  ${name}`);
+		log(`${' '.repeat(9)}${color.cyan(color.underline(link))}`);
+	} else {
+		log(`${' '.repeat(5)} ${symbol}  ${name} ${color.cyan(color.underline(link))}`);
+	}
+};
+
+export function printHelp({
+	commandName,
+	usage,
+	tables,
+	description,
+}: {
+	commandName: string;
+	headline?: string;
+	usage?: string;
+	tables?: Record<string, [command: string, help: string][]>;
+	description?: string;
+}) {
+	const linebreak = () => '';
+	const table = (rows: [string, string][], { padding }: { padding: number }) => {
+		const split = stdout.columns < 60;
+		let raw = '';
+
+		for (const row of rows) {
+			if (split) {
+				raw += `    ${row[0]}\n    `;
+			} else {
+				raw += `${`${row[0]}`.padStart(padding)}`;
+			}
+			raw += '  ' + color.dim(row[1]) + '\n';
+		}
+
+		return raw.slice(0, -1); // remove latest \n
+	};
+
+	let message = [];
+
+	if (usage) {
+		message.push(linebreak(), `${color.green(commandName)} ${color.bold(usage)}`);
+	}
+
+	if (tables) {
+		function calculateTablePadding(rows: [string, string][]) {
+			return rows.reduce((val, [first]) => Math.max(val, first.length), 0);
+		}
+		const tableEntries = Object.entries(tables);
+		const padding = Math.max(...tableEntries.map(([, rows]) => calculateTablePadding(rows)));
+		for (const [, tableRows] of tableEntries) {
+			message.push(linebreak(), table(tableRows, { padding }));
+		}
+	}
+
+	if (description) {
+		message.push(linebreak(), `${description}`);
+	}
+
+	log(message.join('\n') + '\n');
+}
diff --git a/packages/upgrade/src/shell.ts b/packages/upgrade/src/shell.ts
new file mode 100644
index 000000000..47eb4857a
--- /dev/null
+++ b/packages/upgrade/src/shell.ts
@@ -0,0 +1,60 @@
+// This is an extremely simplified version of [`execa`](https://github.com/sindresorhus/execa)
+// intended to keep our dependency size down
+import type { ChildProcess, StdioOptions } from 'node:child_process';
+import type { Readable } from 'node:stream';
+
+import { spawn } from 'node:child_process';
+import { text as textFromStream } from 'node:stream/consumers';
+
+export interface ExecaOptions {
+	cwd?: string | URL;
+	stdio?: StdioOptions;
+	timeout?: number;
+}
+export interface Output {
+	stdout: string;
+	stderr: string;
+	exitCode: number;
+}
+const text = (stream: NodeJS.ReadableStream | Readable | null) =>
+	stream ? textFromStream(stream).then((t) => t.trimEnd()) : '';
+
+let signal: AbortSignal;
+export async function shell(
+	command: string,
+	flags: string[],
+	opts: ExecaOptions = {}
+): Promise<Output> {
+	let child: ChildProcess;
+	let stdout = '';
+	let stderr = '';
+	if (!signal) {
+		const controller = new AbortController();
+		// Ensure spawned process is cancelled on exit
+		process.once('beforeexit', () => controller.abort());
+		process.once('exit', () => controller.abort());
+		signal = controller.signal;
+	}
+	try {
+		child = spawn(command, flags, {
+			cwd: opts.cwd,
+			shell: true,
+			stdio: opts.stdio,
+			timeout: opts.timeout,
+			signal
+		});
+		const done = new Promise((resolve) => child.on('close', resolve));
+		[stdout, stderr] = await Promise.all([text(child.stdout), text(child.stderr)]);
+		await done;
+	} catch (e) {
+		throw { stdout, stderr, exitCode: 1 };
+	}
+	const { exitCode } = child;
+	if (exitCode === null) {
+		throw new Error('Timeout');
+	}
+	if (exitCode !== 0) {
+		throw new Error(stderr);
+	}
+	return { stdout, stderr, exitCode };
+}