worker: add argv constructor option

A convenience option to populate `process.argv` in worker threads.

PR-URL: #30559
Fixes: #30531
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: Denys Otrishko <shishugi@gmail.com>

doc/api/worker_threads.md

@@ -510,6 +510,9 @@ changes:
   - version: v13.2.0
     pr-url: https://github.com/nodejs/node/pull/26628
     description: The `resourceLimits` option was introduced.
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/30559
+    description: The `argv` option was introduced.
 -->
 
 * `filename` {string} The path to the Worker’s main script. Must be
@@ -518,6 +521,10 @@ changes:
   If `options.eval` is `true`, this is a string containing JavaScript code
   rather than a path.
 * `options` {Object}
+  * `argv` {any[]} List of arguments which would be stringified and appended to
+    `process.argv` in the worker. This is mostly similar to the `workerData`
+    but the values will be available on the global `process.argv` as if they
+    were passed as CLI options to the script.
   * `env` {Object} If set, specifies the initial value of `process.env` inside
     the Worker thread. As a special value, [`worker.SHARE_ENV`][] may be used
     to specify that the parent thread and the child thread should share their

lib/internal/main/worker_thread.js

@@ -92,6 +92,7 @@ if (process.env.NODE_CHANNEL_FD) {
 port.on('message', (message) => {
   if (message.type === LOAD_SCRIPT) {
     const {
+      argv,
       cwdCounter,
       filename,
       doEval,
@@ -115,6 +116,9 @@ port.on('message', (message) => {
     assert(!CJSLoader.hasLoadedAnyUserCJSModule);
     loadPreloadModules();
     initializeFrozenIntrinsics();
+    if (argv !== undefined) {
+      process.argv = process.argv.concat(argv);
+    }
     publicWorker.parentPort = publicPort;
     publicWorker.workerData = workerData;
 
@@ -143,12 +147,22 @@ port.on('message', (message) => {
     port.postMessage({ type: UP_AND_RUNNING });
     if (doEval) {
       const { evalScript } = require('internal/process/execution');
-      evalScript('[worker eval]', filename);
+      const name = '[worker eval]';
+      // This is necessary for CJS module compilation.
+      // TODO: pass this with something really internal.
+      ObjectDefineProperty(process, '_eval', {
+        configurable: true,
+        enumerable: true,
+        value: filename,
+      });
+      process.argv.splice(1, 0, name);
+      evalScript(name, filename);
     } else {
       // script filename
       // runMain here might be monkey-patched by users in --require.
       // XXX: the monkey-patchability here should probably be deprecated.
-      CJSLoader.Module.runMain(process.argv[1] = filename);
+      process.argv.splice(1, 0, filename);
+      CJSLoader.Module.runMain(filename);
     }
   } else if (message.type === STDIO_PAYLOAD) {
     const { stream, chunk, encoding } = message;

lib/internal/worker.js

@@ -82,9 +82,16 @@ class Worker extends EventEmitter {
     validateString(filename, 'filename');
     if (options.execArgv && !ArrayIsArray(options.execArgv)) {
       throw new ERR_INVALID_ARG_TYPE('options.execArgv',
-                                     'array',
+                                     'Array',
                                      options.execArgv);
     }
+    let argv;
+    if (options.argv) {
+      if (!ArrayIsArray(options.argv)) {
+        throw new ERR_INVALID_ARG_TYPE('options.argv', 'Array', options.argv);
+      }
+      argv = options.argv.map(String);
+    }
     if (!options.eval) {
       if (!path.isAbsolute(filename) && !/^\.\.?[\\/]/.test(filename)) {
         throw new ERR_WORKER_PATH(filename);
@@ -154,6 +161,7 @@ class Worker extends EventEmitter {
     this[kPublicPort].on('message', (message) => this.emit('message', message));
     setupPortReferencing(this[kPublicPort], this, 'message');
     this[kPort].postMessage({
+      argv,
       type: messageTypes.LOAD_SCRIPT,
       filename,
       doEval: !!options.eval,

test/parallel/test-worker-process-argv.js

@@ -0,0 +1,49 @@
+'use strict';
+const common = require('../common');
+const assert = require('assert');
+const { Worker, isMainThread, workerData } = require('worker_threads');
+
+if (isMainThread) {
+  assert.throws(() => {
+    new Worker(__filename, { argv: 'foo' });
+  }, {
+    code: 'ERR_INVALID_ARG_TYPE'
+  });
+
+  [
+    new Worker(__filename, {
+      argv: [null, 'foo', 123, Symbol('bar')],
+      // Asserts only if the worker is started by the test.
+      workerData: 'assert-argv'
+    }),
+    new Worker(`
+      const assert = require('assert');
+      assert.deepStrictEqual(
+        process.argv,
+        [process.execPath, '[worker eval]']
+      );
+    `, {
+      eval: true
+    }),
+    new Worker(`
+      const assert = require('assert');
+      assert.deepStrictEqual(
+        process.argv,
+        [process.execPath, '[worker eval]', 'null', 'foo', '123',
+        String(Symbol('bar'))]
+      );
+    `, {
+      argv: [null, 'foo', 123, Symbol('bar')],
+      eval: true
+    })
+  ].forEach((worker) => {
+    worker.on('exit', common.mustCall((code) => {
+      assert.strictEqual(code, 0);
+    }));
+  });
+} else if (workerData === 'assert-argv') {
+  assert.deepStrictEqual(
+    process.argv,
+    [process.execPath, __filename, 'null', 'foo', '123', String(Symbol('bar'))]
+  );
+}