Fix pthread + modularize + running in node worker (#21832)

The issue here was the special case for the setting of `scriptDirectory` under
nodejs when `ENVIRONMENT_IS_WORKER`.

Previously this path was not being hit when the main thread was running in
a worker because we were not setting `ENVIRONMENT_IS_WORKER` in
this case.   This was fixed in #21701 and `ENVIRONMENT_IS_WORKER`
was correctly set, but that meant that `scriptDirectory` then started being
set incorrectly.

Fixes: #21827

Author: sbc100

src/shell.js

@@ -198,6 +198,9 @@ if (ENVIRONMENT_IS_WORKER) {
 // `/` should be present at the end if `scriptDirectory` is not empty
 var scriptDirectory = '';
 function locateFile(path) {
+#if RUNTIME_DEBUG
+  dbg('locateFile:', path, 'scriptDirectory:', scriptDirectory);
+#endif
 #if expectToReceiveOnModule('locateFile')
   if (Module['locateFile']) {
     return Module['locateFile'](path, scriptDirectory);
@@ -232,18 +235,14 @@ if (ENVIRONMENT_IS_NODE) {
   var fs = require('fs');
   var nodePath = require('path');
 
-  if (ENVIRONMENT_IS_WORKER) {
-    scriptDirectory = nodePath.dirname(scriptDirectory) + '/';
-  } else {
 #if EXPORT_ES6
-    // EXPORT_ES6 + ENVIRONMENT_IS_NODE always requires use of import.meta.url,
-    // since there's no way getting the current absolute path of the module when
-    // support for that is not available.
-    scriptDirectory = require('url').fileURLToPath(new URL('./', import.meta.url)); // includes trailing slash
+  // EXPORT_ES6 + ENVIRONMENT_IS_NODE always requires use of import.meta.url,
+  // since there's no way getting the current absolute path of the module when
+  // support for that is not available.
+  scriptDirectory = require('url').fileURLToPath(new URL('./', import.meta.url)); // includes trailing slash
 #else
-    scriptDirectory = __dirname + '/';
+  scriptDirectory = __dirname + '/';
 #endif
-  }
 
 #include "node_shell_read.js"
 

src/wasm_worker.js

@@ -23,6 +23,7 @@ if (ENVIRONMENT_IS_NODE) {
     self: global,
     require,
     __filename,
+    __dirname,
     Worker: nodeWorkerThreads.Worker,
     importScripts: (f) => vm.runInThisContext(fs.readFileSync(f, 'utf8'), {filename: f}),
     postMessage: (msg) => parentPort.postMessage(msg),

test/test_other.py

@@ -10166,21 +10166,44 @@ def test_node_js_run_from_different_directory(self):
 
   # Tests that a pthreads + modularize build can be run in node js
   @node_pthreads
-  def test_node_js_pthread_module(self):
+  @parameterized({
+    '': (False,),
+    'es6': (True,),
+  })
+  def test_node_js_pthread_module(self, es6):
     # create module loader script
+    if es6:
+      ext = '.mjs'
+      create_file('moduleLoader.mjs', '''
+        import test_module from "./subdir/module.mjs";
+        test_module().then((test_module_instance) => {
+          test_module_instance._main();
+        });
+        ''')
+    else:
+      ext = '.js'
+      create_file('moduleLoader.js', '''
+        const test_module = require("./subdir/module.js");
+        test_module().then((test_module_instance) => {
+          test_module_instance._main();
+        });
+        ''')
     ensure_dir('subdir')
-    create_file('subdir/moduleLoader.js', '''
-const test_module = require("./module");
-test_module().then((test_module_instance) => {
-  test_module_instance._main();
-});
-''')
 
     # build hello_world.c
-    self.run_process([EMCC, test_file('hello_world.c'), '-o', Path('subdir/module.js'), '-pthread', '-sPTHREAD_POOL_SIZE=2', '-sMODULARIZE', '-sEXPORT_NAME=test_module', '-sENVIRONMENT=worker,node'])
+    self.run_process([EMCC, test_file('hello_world.c'), '-o', 'subdir/module' + ext, '-pthread', '-sPTHREAD_POOL_SIZE=2', '-sMODULARIZE', '-sEXPORT_NAME=test_module'] + self.get_emcc_args())
 
     # run the module
-    ret = self.run_js('subdir/moduleLoader.js')
+    ret = self.run_js('moduleLoader' + ext)
+    self.assertContained('hello, world!', ret)
+
+    create_file('workerLoader.js', f'''
+      const {{ Worker, isMainThread }} = require('worker_threads');
+      new Worker('./moduleLoader{ext}');
+      ''')
+
+    # run the same module, but inside of a worker
+    ret = self.run_js('workerLoader.js')
     self.assertContained('hello, world!', ret)
 
   @no_windows('node system() does not seem to work, see https://github.com/emscripten-core/emscripten/pull/10547')