1 files changed, 60 insertions, 0 deletions
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 };
+}