Add filterNodeArgumentsForWorkerThreads option

docs/06-configuration.md

@@ -337,3 +337,19 @@ These may also export a function which is then invoked, and can receive argument
 The `nodeArguments` configuration may be used to specify additional arguments for launching worker processes. These are combined with `--node-arguments` passed on the CLI and any arguments passed to the `node` binary when starting AVA.
 
 [CLI]: ./05-command-line.md
+
+## Thread arguments filter
+
+In a config file only, `threadArgumentsFilter` may provide a function used for filtering `nodeArguments` sent to worker threads. This enables excluding arguments that throw if sent to a thread. The filter is ignored by worker processes.
+
+`ava.config.js`:
+```js
+const processOnly = new Set([
+	'--allow-natives-syntax',
+	'--expose-gc'
+]);
+
+export default {
+	threadArgumentsFilter: argument => !processOnly.has(argument)
+}
+```

lib/cli.js

@@ -388,9 +388,16 @@ export default async function loadCli() { // eslint-disable-line complexity
 		exit(error.message);
 	}
 
+	const workerThreads = combined.workerThreads !== false;
+
 	let nodeArguments;
 	try {
 		nodeArguments = normalizeNodeArguments(conf.nodeArguments, argv['node-arguments']);
+		nodeArguments ??= process.execArgv;
+		if (workerThreads && 'threadArgumentsFilter' in conf) {
+			const {threadArgumentsFilter: filter} = conf;
+			nodeArguments = nodeArguments.filter(argument => filter(argument));
+		}
 	} catch (error) {
 		exit(error.message);
 	}

lib/fork.js

@@ -60,7 +60,7 @@ const createWorker = (options, execArgv) => {
 	};
 };
 
-export default function loadFork(file, options, execArgv = process.execArgv) {
+export default function loadFork(file, options, execArgv) {
 	let finished = false;
 
 	const emitter = new Emittery();

lib/load-config.js

@@ -157,6 +157,10 @@ export async function loadConfig({configFile, resolveFrom = process.cwd(), defau
 		...defaults, nonSemVerExperiments: {}, ...fileConf, ...packageConf, projectDir, configFile,
 	};
 
+	if ('threadArgumentsFilter' in config && typeof config.threadArgumentsFilter !== 'function') {
+		throw new Error(`threadArgumentsFilter from ${fileForErrorMessage} must be a function`);
+	}
+
 	const {nonSemVerExperiments: experiments} = config;
 	if (!isPlainObject(experiments)) {
 		throw new Error(`nonSemVerExperiments from ${fileForErrorMessage} must be an object`);

test-tap/api.js

@@ -1,5 +1,6 @@
 import fs from 'node:fs';
 import path from 'node:path';
+import process from 'node:process';
 import {fileURLToPath} from 'node:url';
 
 import ciInfo from 'ci-info';
@@ -20,6 +21,7 @@ async function apiCreator(options = {}) {
 	options.globs = normalizeGlobs({
 		files: options.files, ignoredByWatcher: options.watchMode?.ignoreChanges, extensions: options.extensions, providers: [],
 	});
+	options.nodeArguments = process.execArgv;
 	const instance = new Api(options);
 
 	return instance;

test-tap/fixture/load-config/non-function/ava.config.js

@@ -0,0 +1,3 @@
+export default {
+	threadArgumentsFilter: [],
+};

test-tap/fixture/load-config/non-function/package.json

@@ -0,0 +1,3 @@
+{
+	"type": "module"
+}

test/config/loader.js

@@ -117,6 +117,8 @@ test.serial('throws an error if a .js config file has no default export', notOk(
 
 test.serial('throws an error if a config file contains `ava` property', notOk('contains-ava-property'));
 
+test.serial('throws an error if a config file contains a non-function `threadArgumentsFilter` property', notOk('non-function'));
+
 test.serial('throws an error if a config file contains a non-object `nonSemVerExperiments` property', notOk('non-object-experiments'));
 
 test.serial('throws an error if a config file enables an unsupported experiment', notOk('unsupported-experiments'));

test/config/snapshots/loader.js.md

@@ -40,6 +40,12 @@ Generated by [AVA](https://avajs.dev).
 
     'Encountered ’ava’ property in ava.config.js; avoid wrapping the configuration'
 
+## throws an error if a config file contains a non-function `threadArgumentsFilter` property
+
+> error message
+
+    'threadArgumentsFilter from ava.config.js must be a function'
+
 ## throws an error if a config file contains a non-object `nonSemVerExperiments` property
 
 > error message

test/node-arguments/fixtures/thread-arguments-filter/package.json

@@ -0,0 +1,3 @@
+{
+	"type": "module"
+}

test/node-arguments/fixtures/thread-arguments-filter/process.js

@@ -0,0 +1,7 @@
+import test from 'ava';
+
+test('exec arguments unfiltered', t => {
+	t.plan(2);
+	t.truthy(process.execArgv.includes('--throw-deprecation'));
+	t.truthy(process.execArgv.includes('--allow-natives-syntax'));
+});

test/node-arguments/fixtures/thread-arguments-filter/thread-arguments-filter.config.mjs

@@ -0,0 +1,9 @@
+const processOnly = new Set(['--allow-natives-syntax']);
+
+export default {
+	nodeArguments: [
+		'--throw-deprecation',
+		'--allow-natives-syntax',
+	],
+	threadArgumentsFilter: argument => !processOnly.has(argument),
+};

test/node-arguments/fixtures/thread-arguments-filter/thread.js

@@ -0,0 +1,7 @@
+import test from 'ava';
+
+test('exec arguments filtered', t => {
+	t.plan(2);
+	t.truthy(process.execArgv.includes('--throw-deprecation'));
+	t.falsy(process.execArgv.includes('--allow-natives-syntax'));
+});

test/node-arguments/snapshots/test.js.md

@@ -15,6 +15,28 @@ Generated by [AVA](https://avajs.dev).
       },
     ]
 
+## `threadArgumentsFilter` configuration filters arguments for worker thread
+
+> tests pass
+
+    [
+      {
+        file: 'thread.js',
+        title: 'exec arguments filtered',
+      },
+    ]
+
+## `threadArgumentsFilter` configuration ignored for worker process
+
+> tests pass
+
+    [
+      {
+        file: 'process.js',
+        title: 'exec arguments unfiltered',
+      },
+    ]
+
 ## detects incomplete --node-arguments
 
 > fails with message

test/node-arguments/test.js

@@ -13,6 +13,26 @@ test('passed node arguments to workers', async t => {
 	t.snapshot(result.stats.passed, 'tests pass');
 });
 
+test('`threadArgumentsFilter` configuration filters arguments for worker thread', async t => {
+	const options = {
+		cwd: cwd('thread-arguments-filter'),
+	};
+
+	const result = await fixture(['--config=thread-arguments-filter.config.mjs', 'thread.js'], options);
+
+	t.snapshot(result.stats.passed, 'tests pass');
+});
+
+test('`threadArgumentsFilter` configuration ignored for worker process', async t => {
+	const options = {
+		cwd: cwd('thread-arguments-filter'),
+	};
+
+	const result = await fixture(['--config=thread-arguments-filter.config.mjs', '--no-worker-threads', 'process.js'], options);
+
+	t.snapshot(result.stats.passed, 'tests pass');
+});
+
 test('detects incomplete --node-arguments', async t => {
 	const options = {
 		cwd: cwd('node-arguments'),