Change default value of serialization option to advanced

index.d.ts

@@ -597,7 +597,7 @@ type CommonOptions<IsSync extends boolean = boolean> = {
 
 	[More info.](https://nodejs.org/api/child_process.html#child_process_advanced_serialization)
 
-	@default 'json'
+	@default 'advanced'
 	*/
 	readonly serialization?: IfAsync<IsSync, 'json' | 'advanced'>;
 

lib/arguments/options.js

@@ -84,6 +84,7 @@ const addDefaultOptions = ({
 	forceKillAfterDelay = true,
 	lines = false,
 	ipc = false,
+	serialization = 'advanced',
 	...options
 }) => ({
 	...options,
@@ -103,6 +104,7 @@ const addDefaultOptions = ({
 	forceKillAfterDelay,
 	lines,
 	ipc,
+	serialization,
 });
 
 const DEFAULT_MAX_BUFFER = 1000 * 1000 * 100;

readme.md

@@ -848,7 +848,7 @@ Enables exchanging messages with the subprocess using [`subprocess.send(value)`]
 #### serialization
 
 Type: `string`\
-Default: `'json'`
+Default: `'advanced'`
 
 Specify the kind of serialization used for sending messages between subprocesses when using the [`ipc`](#ipc) option:
 	- `json`: Uses `JSON.stringify()` and `JSON.parse()`.

test/arguments/node.js

@@ -1,3 +1,4 @@
+import {once} from 'node:events';
 import {dirname, relative} from 'node:path';
 import process from 'node:process';
 import {pathToFileURL} from 'node:url';
@@ -256,3 +257,22 @@ const testNoShell = async (t, execaMethod) => {
 test('Cannot use "shell: true" - execaNode()', testNoShell, execaNode);
 test('Cannot use "shell: true" - "node" option', testNoShell, runWithNodeOption);
 test('Cannot use "shell: true" - "node" option sync', testNoShell, runWithNodeOptionSync);
+
+test('The "serialization" option defaults to "advanced"', async t => {
+	const subprocess = execa('node', ['ipc-echo.js'], {ipc: true});
+	subprocess.send([0n]);
+	const [message] = await once(subprocess, 'message');
+	t.is(message[0], 0n);
+	await subprocess;
+});
+
+test('The "serialization" option can be set to "json"', async t => {
+	const subprocess = execa('node', ['ipc-echo.js'], {ipc: true, serialization: 'json'});
+	t.throws(() => {
+		subprocess.send([0n]);
+	}, {message: /serialize a BigInt/});
+	subprocess.send(0);
+	const [message] = await once(subprocess, 'message');
+	t.is(message, 0);
+	await subprocess;
+});

test/fixtures/ipc-echo.js

@@ -0,0 +1,6 @@
+#!/usr/bin/env node
+import process from 'node:process';
+
+process.once('message', message => {
+	process.send(message);
+});