Improve promise.stdout error handling (#39)

index.js

@@ -21,11 +21,11 @@ export default function nanoSpawn(file, commandArguments = [], options = {}) {
 	const subprocess = spawn(...escapeArguments(file, commandArguments, forcedShell), spawnOptions);
 
 	useInput(subprocess, input);
-	const promise = getResult(subprocess, start, command);
+	const resultPromise = getResult(subprocess, start, command);
 
-	const stdoutLines = lineIterator(subprocess.stdout);
-	const stderrLines = lineIterator(subprocess.stderr);
-	return Object.assign(promise, {
+	const stdoutLines = lineIterator(subprocess.stdout, resultPromise);
+	const stderrLines = lineIterator(subprocess.stderr, resultPromise);
+	return Object.assign(resultPromise, {
 		subprocess,
 		[Symbol.asyncIterator]: () => combineAsyncIterators(stdoutLines, stderrLines),
 		stdout: stdoutLines,

iterable.js

@@ -20,19 +20,23 @@ export async function * combineAsyncIterators(iterator1, iterator2) {
 	}
 }
 
-export async function * lineIterator(iterable) {
-	if (!iterable) {
+export async function * lineIterator(stream, resultPromise) {
+	if (!stream) {
 		return;
 	}
 
-	let buffer = '';
-	for await (const chunk of iterable) {
-		const lines = `${buffer}${chunk}`.split(/\r?\n/);
-		buffer = lines.pop(); // Keep last line in buffer as it may not be complete
-		yield * lines;
-	}
+	try {
+		let buffer = '';
+		for await (const chunk of stream.iterator({destroyOnReturn: false})) {
+			const lines = `${buffer}${chunk}`.split(/\r?\n/);
+			buffer = lines.pop(); // Keep last line in buffer as it may not be complete
+			yield * lines;
+		}
 
-	if (buffer) {
-		yield buffer; // Yield any remaining data as the last line
+		if (buffer) {
+			yield buffer; // Yield any remaining data as the last line
+		}
+	} finally {
+		await resultPromise;
 	}
 }