transfer-out: transfer out

scripts/lib/exec.ts

@@ -0,0 +1,66 @@
+import { execFile } from 'child_process'
+
+type ExecOpts = {
+	pwd?: string
+	processStdoutLine?: (line: string) => void
+	processStderrLine?: (line: string) => void
+}
+
+export async function exec(
+	command: string,
+	args: (string | null)[],
+	{
+		pwd = process.cwd(),
+		processStdoutLine = (line) => process.stdout.write(`${line}\n`),
+		processStderrLine = (line) => process.stderr.write(`${line}\n`),
+	}: ExecOpts = {}
+): Promise<string> {
+	console.log(`> $ ${command} ${args.join(' ')} (in ${pwd}))`)
+	return new Promise((resolve, reject) => {
+		const data: string[] = []
+
+		const childProcess = execFile(
+			command,
+			args.filter((arg): arg is string => !!arg),
+			{ cwd: pwd },
+			(err) => {
+				if (err) reject(err)
+				else resolve(data.join(''))
+			}
+		)
+
+		let pendingStdoutLine = ''
+		childProcess.stdout!.on('data', (chunk) => {
+			const chunkString: string = chunk.toString('utf-8')
+			data.push(chunkString)
+
+			const lines = chunkString.split('\n')
+			lines[0] = pendingStdoutLine + lines[0]
+			pendingStdoutLine = lines.pop() ?? ''
+
+			for (const line of lines) {
+				processStdoutLine(line)
+			}
+		})
+		childProcess.stdout!.on('close', () => {
+			processStdoutLine(pendingStdoutLine)
+		})
+
+		let pendingStderrLine = ''
+		childProcess.stderr!.on('data', (chunk) => {
+			const chunkString: string = chunk.toString('utf-8')
+			data.push(chunkString)
+
+			const lines = chunkString.split('\n')
+			lines[0] = pendingStderrLine + lines[0]
+			pendingStderrLine = lines.pop() ?? ''
+
+			for (const line of lines) {
+				processStderrLine(line)
+			}
+		})
+		childProcess.stderr!.on('close', () => {
+			processStderrLine(pendingStderrLine)
+		})
+	})
+}