[esm-integration] Enable direct execution of modules under node (#24112)

Author: sbc100

test/common.py

@@ -1937,21 +1937,17 @@ def do_run_in_out_file_test(self, srcfile, **kwargs):
   ## Does a complete test - builds, runs, checks output, etc.
   def _build_and_run(self, filename, expected_output, args=None,
                      no_build=False,
-                     libraries=None,
-                     includes=None,
                      assert_returncode=0, assert_identical=False, assert_all=False,
-                     check_for_error=True, force_c=False, emcc_args=None,
+                     check_for_error=True,
                      interleaved_output=True,
                      regex=False,
-                     output_basename=None):
+                     **kwargs):
     logger.debug(f'_build_and_run: {filename}')
 
     if no_build:
       js_file = filename
     else:
-      js_file = self.build(filename, libraries=libraries, includes=includes,
-                           force_c=force_c, emcc_args=emcc_args,
-                           output_basename=output_basename)
+      js_file = self.build(filename, **kwargs)
     self.assertExists(js_file)
 
     engines = self.js_engines.copy()

test/core/test_esm_integration.expected.mjs

@@ -2,3 +2,12 @@
 // in order to avoid issues with circular dependencies.
 import * as unused from './hello_world.wasm';
 export { default, _foo, _main, err, stringToNewUTF8 } from './hello_world.support.mjs';
+
+// When run as the main module under node, execute main directly here
+import init from './hello_world.support.mjs';
+const isNode = typeof process == 'object' && typeof process.versions == 'object' && typeof process.versions.node == 'string' && process.type != 'renderer';
+if (isNode) {
+  const url = await import('url');
+  const isMainModule = url.pathToFileURL(process.argv[1]).href === import.meta.url;
+  if (isMainModule) await init();
+}

test/test_core.py

@@ -9562,6 +9562,12 @@ def test_wasm_worker_malloc(self):
   def test_wasm_worker_wait_async(self):
     self.do_runf('atomic/test_wait_async.c', emcc_args=['-sWASM_WORKERS'])
 
+  @requires_node_canary
+  @no_wasm64("wasm64 requires wasm export wrappers")
+  def test_esm_integration_main(self):
+    self.node_args += ['--experimental-wasm-modules', '--no-warnings']
+    self.do_runf('hello_world.c', 'hello, world!', emcc_args=['-sWASM_ESM_INTEGRATION', '-Wno-experimental'], output_suffix='.mjs')
+
   @requires_node_canary
   @no_wasm64("wasm64 requires wasm export wrappers")
   def test_esm_integration(self):

tools/link.py

@@ -2128,6 +2128,18 @@ def create_esm_wrapper(wrapper_file, support_target, wasm_target):
     wrapper.append(f"export {{ default, {js_exports} }} from '{support_url}';")
   else:
     wrapper.append(f"export {{ default }} from '{support_url}';")
+
+  if settings.ENVIRONMENT_MAY_BE_NODE and settings.INVOKE_RUN and settings.EXPECT_MAIN:
+    wrapper.append(f'''
+// When run as the main module under node, execute main directly here
+import init from '{support_url}';
+const isNode = typeof process == 'object' && typeof process.versions == 'object' && typeof process.versions.node == 'string' && process.type != 'renderer';
+if (isNode) {{
+  const url = await import('url');
+  const isMainModule = url.pathToFileURL(process.argv[1]).href === import.meta.url;
+  if (isMainModule) await init();
+}}''')
+
   write_file(wrapper_file, '\n'.join(wrapper) + '\n')
 
   # FIXME(sbc): This is a huge hack to rename the imports in the