From be712ca46ed0afb19e2bff3a01f9edd8085f16bb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C5=81ukasz=20Kwinta?=
 <33606064+lkwinta@users.noreply.github.com>
Date: Fri, 18 Jul 2025 13:10:46 +0200
Subject: [PATCH 1/6] Add modularize to file_packager.py

fix python format

apply more ruff fixes

fix pipeline

revert file to the most actual version and apply changes

add modularize to options class

add utilization of EXPORT_NAME with modularize option

simplify declaration of the modularize function

arg documentation

address @sbc100 review

Fix codegen new line formatting

Add file_packager tests and changelog mention

fix some stylistic issues

gichange file_packager modularize test

simplyfi tests

fix test

rename to export_es6

async function promise behaviour

cleanup test

address @sbc100 review

simplify the test

rename promise handlers

introduce createRequire in es6 mode

alternative way to import require
---
 ChangeLog.md           |  2 ++
 test/test_other.py     | 42 +++++++++++++++++++++++++++++++
 tools/file_packager.py | 57 ++++++++++++++++++++++++++++++++++++------
 3 files changed, 93 insertions(+), 8 deletions(-)

diff --git a/ChangeLog.md b/ChangeLog.md
index 4dd11d39920a6..d45542b8c13b7 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -41,6 +41,8 @@ See docs/process.md for more on how version tagging works.
 - emcc will now error if `MINIMAL_RUNTIME_STREAMING_WASM_COMPILATION` or
   `MINIMAL_RUNTIME_STREAMING_WASM_INSTANTIATION` are used with `SINGLE_FILE`.
   These are fundamentally incompatible but were previously ignored. (#24849)
+- `--export-es6` flag was added to `file_packager.py` available when run 
+  standalone, to enable ES6 imports of generated JavaScript code (#24737)
 
 4.0.12 - 08/01/25
 -----------------
diff --git a/test/test_other.py b/test/test_other.py
index bff7e7d3fea9c..1c3fea743e232 100644
--- a/test/test_other.py
+++ b/test/test_other.py
@@ -3919,6 +3919,11 @@ def test_file_packager_returns_error_if_target_equal_to_jsoutput(self):
     err = self.expect_fail([FILE_PACKAGER, 'test.data', '--js-output=test.data'])
     self.assertContained(MESSAGE, err)
 
+  def test_file_packager_returns_error_if_emcc_and_export_es6(self):
+    MESSAGE = 'error: Can\'t use --export-es6 option together with --from-emcc since the code should be embedded within emcc\'s code'
+    err = self.expect_fail([FILE_PACKAGER, 'test.data', '--export-es6', '--from-emcc'])
+    self.assertContained(MESSAGE, err)
+
   def test_file_packager_embed(self):
     create_file('data.txt', 'hello data')
 
@@ -3945,6 +3950,43 @@ def test_file_packager_embed(self):
     output = self.run_js('a.out.js')
     self.assertContained('hello data', output)
 
+  def test_file_packager_export_es6(self):
+    create_file('smth.txt', 'hello data')
+    self.run_process([FILE_PACKAGER, 'test.data', '--export-es6', '--preload', 'smth.txt', '--js-output=dataFileLoader.js'])
+
+    create_file('test.c', '''
+    #include <stdio.h>
+    #include <emscripten.h>
+
+    EMSCRIPTEN_KEEPALIVE int test_fun() {
+      FILE* f = fopen("smth.txt", "r");
+      char buf[64] = {0};
+      int rtn = fread(buf, 1, 64, f);
+      buf[rtn] = '\\0';
+      fclose(f);
+      printf("%s\\n", buf);
+      return 0;
+    }
+    ''')
+    self.run_process([EMCC, 'test.c', '-sFORCE_FILESYSTEM', '-sMODULARIZE', '-sEXPORT_ES6', '-o', 'moduleFile.js'])
+
+    create_file('run.js', '''
+    import loadDataFile from './dataFileLoader.js'
+    import {default as loadModule} from './moduleFile.js'
+
+    loadModule().then((module) => {
+      loadDataFile(module)
+        .catch((cause) => Promise.reject(cause))
+        .then(() => {
+          module._test_fun();
+        }
+      );
+    });
+    ''')
+
+    output = self.run_js('run.js')
+    self.assertContained('hello data', output)
+
   @crossplatform
   def test_file_packager_depfile(self):
     create_file('data1.txt', 'data1')
diff --git a/tools/file_packager.py b/tools/file_packager.py
index ad61f0634acdd..88c252662e1ad 100755
--- a/tools/file_packager.py
+++ b/tools/file_packager.py
@@ -21,7 +21,7 @@
 
 Usage:
 
-  file_packager TARGET [--preload A [B..]] [--embed C [D..]] [--exclude E [F..]] [--js-output=OUTPUT.js] [--no-force] [--use-preload-cache] [--indexedDB-name=EM_PRELOAD_CACHE] [--separate-metadata] [--lz4] [--use-preload-plugins] [--no-node] [--help]
+  file_packager TARGET [--preload A [B..]] [--embed C [D..]] [--exclude E [F..]] [--js-output=OUTPUT.js] [--no-force] [--use-preload-cache] [--indexedDB-name=EM_PRELOAD_CACHE] [--separate-metadata] [--lz4] [--use-preload-plugins] [--no-node] [--export-es6] [--help]
 
   --preload  ,
   --embed    See emcc --help for more details on those options.
@@ -41,6 +41,8 @@
 
   --export-name=EXPORT_NAME Use custom export name (default is `Module`)
 
+  --export-es6 Wrap generated code inside ES6 exported function
+
   --no-force Don't create output if no valid input file is specified.
 
   --use-preload-cache Stores package in IndexedDB so that subsequent loads don't need to do XHR. Checks package version.
@@ -129,6 +131,7 @@ def __init__(self):
     self.use_preload_plugins = False
     self.support_node = True
     self.wasm64 = False
+    self.export_es6 = False
 
 
 class DataFile:
@@ -362,7 +365,7 @@ def main():  # noqa: C901, PLR0912, PLR0915
   To revalidate these numbers, run `ruff check --select=C901,PLR091`.
   """
   if len(sys.argv) == 1:
-    err('''Usage: file_packager TARGET [--preload A [B..]] [--embed C [D..]] [--exclude E [F..]] [--js-output=OUTPUT.js] [--no-force] [--use-preload-cache] [--indexedDB-name=EM_PRELOAD_CACHE] [--separate-metadata] [--lz4] [--use-preload-plugins] [--no-node] [--help]
+    err('''Usage: file_packager TARGET [--preload A [B..]] [--embed C [D..]] [--exclude E [F..]] [--js-output=OUTPUT.js] [--no-force] [--use-preload-cache] [--indexedDB-name=EM_PRELOAD_CACHE] [--separate-metadata] [--lz4] [--use-preload-plugins] [--no-node] [--export-es6] [--help]
   Try 'file_packager --help' for more details.''')
     return 1
 
@@ -391,6 +394,9 @@ def main():  # noqa: C901, PLR0912, PLR0915
     elif arg == '--no-force':
       options.force = False
       leading = ''
+    elif arg == '--export-es6':
+      options.export_es6 = True
+      leading = ''
     elif arg == '--use-preload-cache':
       options.use_preload_cache = True
       leading = ''
@@ -485,6 +491,11 @@ def main():  # noqa: C901, PLR0912, PLR0915
     diagnostics.error('TARGET should not be the same value of --js-output')
     return 1
 
+  if options.from_emcc and options.export_es6:
+    diagnostics.error('Can\'t use --export-es6 option together with --from-emcc since the code should be embedded '
+        'within emcc\'s code')
+    return 1
+
   walked.append(__file__)
   for file_ in data_files:
     if not should_ignore(file_.srcpath):
@@ -621,13 +632,21 @@ def generate_js(data_target, data_files, metadata):
   if options.from_emcc:
     ret = ''
   else:
-    ret = '''
+    if options.export_es6:
+      ret = 'export default async function loadDataFile(Module) {\n'
+    else:
+      ret = '''
   var Module = typeof %(EXPORT_NAME)s != 'undefined' ? %(EXPORT_NAME)s : {};\n''' % {"EXPORT_NAME": options.export_name}
 
   ret += '''
   Module['expectedDataFileDownloads'] ??= 0;
-  Module['expectedDataFileDownloads']++;
-  (() => {
+  Module['expectedDataFileDownloads']++;'''
+
+  if not options.export_es6:
+    ret += '''
+  (() => {'''
+
+  ret += '''
     // Do not attempt to redownload the virtual filesystem data when in a pthread or a Wasm Worker context.
     var isPthread = typeof ENVIRONMENT_IS_PTHREAD != 'undefined' && ENVIRONMENT_IS_PTHREAD;
     var isWasmWorker = typeof ENVIRONMENT_IS_WASM_WORKER != 'undefined' && ENVIRONMENT_IS_WASM_WORKER;
@@ -635,6 +654,16 @@ def generate_js(data_target, data_files, metadata):
 
   if options.support_node:
     ret += "    var isNode = typeof process === 'object' && typeof process.versions === 'object' && typeof process.versions.node === 'string';\n"
+
+  if options.support_node and options.export_es6:
+        ret += '''if (isNode) {
+    const { createRequire } = await import('module');
+    /** @suppress{duplicate} */
+    var require = createRequire(import.meta.url);
+  }\n'''
+
+  if options.export_es6:
+    ret += 'return new Promise((loadDataResolve, loadDataReject) => {\n'
   ret += '    async function loadPackage(metadata) {\n'
 
   code = '''
@@ -684,6 +713,8 @@ def generate_js(data_target, data_files, metadata):
     create_data = '''// canOwn this data in the filesystem, it is a slide into the heap that will never change
           Module['FS_createDataFile'](this.name, null, byteArray, true, true, true);
           Module['removeRunDependency'](`fp ${that.name}`);'''
+    ready_promise = '''
+          loadDataResolve();'''
 
     if not options.lz4:
       # Data requests - for getting a block of data out of the big archive - have
@@ -710,14 +741,14 @@ def generate_js(data_target, data_files, metadata):
         finish: function(byteArray) {
           var that = this;
           %s
-          this.requests[this.name] = null;
+          this.requests[this.name] = null;%s
         }
       };
 
       var files = metadata['files'];
       for (var i = 0; i < files.length; ++i) {
         new DataRequest(files[i]['start'], files[i]['end'], files[i]['audio'] || 0).open('GET', files[i]['filename']);
-      }\n''' % (create_preloaded if options.use_preload_plugins else create_data)
+      }\n''' % (create_preloaded if options.use_preload_plugins else create_data, ready_promise if options.export_es6 else '')
 
   if options.has_embedded and not options.obj_output:
     diagnostics.warn('--obj-output is recommended when using --embed.  This outputs an object file for linking directly into your application is more efficient than JS encoding')
@@ -958,6 +989,9 @@ def generate_js(data_target, data_files, metadata):
           return contents.buffer;
         }'''.strip()
 
+    reject_promise = '''
+          loadDataReject();'''
+
     ret += '''
       async function fetchRemotePackage(packageName, packageSize) {
         %(node_support_code)s
@@ -1128,7 +1162,14 @@ def generate_js(data_target, data_files, metadata):
     }
     loadPackage(%s);\n''' % json.dumps(metadata)
 
-  ret += '''
+  if options.export_es6:
+    ret += '''
+  });
+}
+// END the loadDataFile function
+'''
+  else:
+    ret += '''
   })();\n'''
 
   return ret

From b277aea03a5dcbc05138ee86035980a38cbffa2e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C5=81ukasz=20Kwinta?=
 <33606064+lkwinta@users.noreply.github.com>
Date: Tue, 12 Aug 2025 20:07:55 +0000
Subject: [PATCH 2/6] simplify promise usage

---
 tools/file_packager.py | 33 ++++++++++++---------------------
 1 file changed, 12 insertions(+), 21 deletions(-)

diff --git a/tools/file_packager.py b/tools/file_packager.py
index 88c252662e1ad..ff537156cd480 100755
--- a/tools/file_packager.py
+++ b/tools/file_packager.py
@@ -644,7 +644,7 @@ def generate_js(data_target, data_files, metadata):
 
   if not options.export_es6:
     ret += '''
-  (() => {'''
+  (async () => {'''
 
   ret += '''
     // Do not attempt to redownload the virtual filesystem data when in a pthread or a Wasm Worker context.
@@ -662,8 +662,6 @@ def generate_js(data_target, data_files, metadata):
     var require = createRequire(import.meta.url);
   }\n'''
 
-  if options.export_es6:
-    ret += 'return new Promise((loadDataResolve, loadDataReject) => {\n'
   ret += '    async function loadPackage(metadata) {\n'
 
   code = '''
@@ -713,8 +711,6 @@ def generate_js(data_target, data_files, metadata):
     create_data = '''// canOwn this data in the filesystem, it is a slide into the heap that will never change
           Module['FS_createDataFile'](this.name, null, byteArray, true, true, true);
           Module['removeRunDependency'](`fp ${that.name}`);'''
-    ready_promise = '''
-          loadDataResolve();'''
 
     if not options.lz4:
       # Data requests - for getting a block of data out of the big archive - have
@@ -741,14 +737,14 @@ def generate_js(data_target, data_files, metadata):
         finish: function(byteArray) {
           var that = this;
           %s
-          this.requests[this.name] = null;%s
+          this.requests[this.name] = null;
         }
       };
 
       var files = metadata['files'];
       for (var i = 0; i < files.length; ++i) {
         new DataRequest(files[i]['start'], files[i]['end'], files[i]['audio'] || 0).open('GET', files[i]['filename']);
-      }\n''' % (create_preloaded if options.use_preload_plugins else create_data, ready_promise if options.export_es6 else '')
+      }\n''' % (create_preloaded if options.use_preload_plugins else create_data)
 
   if options.has_embedded and not options.obj_output:
     diagnostics.warn('--obj-output is recommended when using --embed.  This outputs an object file for linking directly into your application is more efficient than JS encoding')
@@ -989,9 +985,6 @@ def generate_js(data_target, data_files, metadata):
           return contents.buffer;
         }'''.strip()
 
-    reject_promise = '''
-          loadDataReject();'''
-
     ret += '''
       async function fetchRemotePackage(packageName, packageSize) {
         %(node_support_code)s
@@ -1096,14 +1089,13 @@ def generate_js(data_target, data_files, metadata):
       if (!fetched) {
         // Note that we don't use await here because we want to execute the
         // the rest of this function immediately.
-        fetchRemotePackage(REMOTE_PACKAGE_NAME, REMOTE_PACKAGE_SIZE).then((data) => {
-          if (fetchedCallback) {
-            fetchedCallback(data);
-            fetchedCallback = null;
-          } else {
-            fetched = data;
-          }
-        })
+        let packageData = await fetchRemotePackage(REMOTE_PACKAGE_NAME, REMOTE_PACKAGE_SIZE);
+        if (fetchedCallback) {
+          fetchedCallback(packageData);
+          fetchedCallback = null;
+        } else {
+          fetched = packageData;
+        }
       }\n'''
 
       code += '''
@@ -1121,7 +1113,7 @@ def generate_js(data_target, data_files, metadata):
   ret += '''
     }
     if (Module['calledRun']) {
-      runWithFS(Module);
+      await runWithFS(Module);
     } else {
       (Module['preRun'] ??= []).push(runWithFS); // FS is not initialized yet, wait for it
     }\n'''
@@ -1160,11 +1152,10 @@ def generate_js(data_target, data_files, metadata):
   else:
     ret += '''
     }
-    loadPackage(%s);\n''' % json.dumps(metadata)
+    await loadPackage(%s);\n''' % json.dumps(metadata)
 
   if options.export_es6:
     ret += '''
-  });
 }
 // END the loadDataFile function
 '''

From f6699706b5ba11fdb94f1edcd8b8e0fadda8c2e9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C5=81ukasz=20Kwinta?=
 <33606064+lkwinta@users.noreply.github.com>
Date: Tue, 12 Aug 2025 20:11:04 +0000
Subject: [PATCH 3/6] simplyfi help code

---
 test/test_other.py     | 6 ++----
 tools/file_packager.py | 3 +--
 2 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/test/test_other.py b/test/test_other.py
index 1c3fea743e232..592e820a92feb 100644
--- a/test/test_other.py
+++ b/test/test_other.py
@@ -3973,10 +3973,9 @@ def test_file_packager_export_es6(self):
     create_file('run.js', '''
     import loadDataFile from './dataFileLoader.js'
     import {default as loadModule} from './moduleFile.js'
-
+    
     loadModule().then((module) => {
       loadDataFile(module)
-        .catch((cause) => Promise.reject(cause))
         .then(() => {
           module._test_fun();
         }
@@ -3984,8 +3983,7 @@ def test_file_packager_export_es6(self):
     });
     ''')
 
-    output = self.run_js('run.js')
-    self.assertContained('hello data', output)
+    self.assertContained('hello data', self.run_js('run.js'))
 
   @crossplatform
   def test_file_packager_depfile(self):
diff --git a/tools/file_packager.py b/tools/file_packager.py
index ff537156cd480..7d21d5d8149ca 100755
--- a/tools/file_packager.py
+++ b/tools/file_packager.py
@@ -492,8 +492,7 @@ def main():  # noqa: C901, PLR0912, PLR0915
     return 1
 
   if options.from_emcc and options.export_es6:
-    diagnostics.error('Can\'t use --export-es6 option together with --from-emcc since the code should be embedded '
-        'within emcc\'s code')
+    diagnostics.error('Can\'t use --export-es6 option together with --from-emcc since the code should be embedded within emcc\'s code')
     return 1
 
   walked.append(__file__)

From ddb448efe2e2cb40a33ba6a174543c696ba2bb9b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C5=81ukasz=20Kwinta?=
 <33606064+lkwinta@users.noreply.github.com>
Date: Tue, 12 Aug 2025 20:16:36 +0000
Subject: [PATCH 4/6] simplyfi test

---
 test/test_other.py | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/test/test_other.py b/test/test_other.py
index 592e820a92feb..7cba06185531c 100644
--- a/test/test_other.py
+++ b/test/test_other.py
@@ -3973,14 +3973,10 @@ def test_file_packager_export_es6(self):
     create_file('run.js', '''
     import loadDataFile from './dataFileLoader.js'
     import {default as loadModule} from './moduleFile.js'
-    
-    loadModule().then((module) => {
-      loadDataFile(module)
-        .then(() => {
-          module._test_fun();
-        }
-      );
-    });
+
+    var module = await loadModule();
+    await loadDataFile(module);
+    module._test_fun();
     ''')
 
     self.assertContained('hello data', self.run_js('run.js'))

From 529e4a23ec97dcbe39b659a235b6004231ca0196 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C5=81ukasz=20Kwinta?=
 <33606064+lkwinta@users.noreply.github.com>
Date: Tue, 12 Aug 2025 20:55:06 +0000
Subject: [PATCH 5/6] explicite promise resolving

---
 tools/file_packager.py | 46 ++++++++++++++++++++++++++----------------
 1 file changed, 29 insertions(+), 17 deletions(-)

diff --git a/tools/file_packager.py b/tools/file_packager.py
index 7d21d5d8149ca..58a7e7272c8c6 100755
--- a/tools/file_packager.py
+++ b/tools/file_packager.py
@@ -492,7 +492,8 @@ def main():  # noqa: C901, PLR0912, PLR0915
     return 1
 
   if options.from_emcc and options.export_es6:
-    diagnostics.error('Can\'t use --export-es6 option together with --from-emcc since the code should be embedded within emcc\'s code')
+    diagnostics.error('Can\'t use --export-es6 option together with --from-emcc since the code should be embedded '
+        'within emcc\'s code')
     return 1
 
   walked.append(__file__)
@@ -643,7 +644,7 @@ def generate_js(data_target, data_files, metadata):
 
   if not options.export_es6:
     ret += '''
-  (async () => {'''
+  (() => {'''
 
   ret += '''
     // Do not attempt to redownload the virtual filesystem data when in a pthread or a Wasm Worker context.
@@ -661,6 +662,8 @@ def generate_js(data_target, data_files, metadata):
     var require = createRequire(import.meta.url);
   }\n'''
 
+  if options.export_es6:
+    ret += 'return new Promise((loadDataResolve, loadDataReject) => {\n'
   ret += '    async function loadPackage(metadata) {\n'
 
   code = '''
@@ -710,6 +713,8 @@ def generate_js(data_target, data_files, metadata):
     create_data = '''// canOwn this data in the filesystem, it is a slide into the heap that will never change
           Module['FS_createDataFile'](this.name, null, byteArray, true, true, true);
           Module['removeRunDependency'](`fp ${that.name}`);'''
+    ready_promise = '''
+          loadDataResolve();'''
 
     if not options.lz4:
       # Data requests - for getting a block of data out of the big archive - have
@@ -736,14 +741,14 @@ def generate_js(data_target, data_files, metadata):
         finish: function(byteArray) {
           var that = this;
           %s
-          this.requests[this.name] = null;
+          this.requests[this.name] = null;%s
         }
       };
 
       var files = metadata['files'];
       for (var i = 0; i < files.length; ++i) {
         new DataRequest(files[i]['start'], files[i]['end'], files[i]['audio'] || 0).open('GET', files[i]['filename']);
-      }\n''' % (create_preloaded if options.use_preload_plugins else create_data)
+      }\n''' % (create_preloaded if options.use_preload_plugins else create_data, ready_promise if options.export_es6 else '')
 
   if options.has_embedded and not options.obj_output:
     diagnostics.warn('--obj-output is recommended when using --embed.  This outputs an object file for linking directly into your application is more efficient than JS encoding')
@@ -1046,6 +1051,10 @@ def generate_js(data_target, data_files, metadata):
 
     code += '''
       Module['preloadResults'] ??= {};\n'''
+    catch_case = '''
+          .catch((error) => {
+            loadDataReject(error);
+          })'''
 
     if options.use_preload_cache:
       code += '''
@@ -1072,10 +1081,10 @@ def generate_js(data_target, data_files, metadata):
             }
           }
         } catch(e) {
-          await preloadFallback(e);
+          await preloadFallback(e)%s;
         }
 
-        Module['setStatus']?.('Downloading...');\n'''
+        Module['setStatus']?.('Downloading...');\n''' % (catch_case if options.export_es6 else '')
     else:
       # Not using preload cache, so we might as well start the xhr ASAP,
       # potentially before JS parsing of the main codebase if it's after us.
@@ -1088,14 +1097,16 @@ def generate_js(data_target, data_files, metadata):
       if (!fetched) {
         // Note that we don't use await here because we want to execute the
         // the rest of this function immediately.
-        let packageData = await fetchRemotePackage(REMOTE_PACKAGE_NAME, REMOTE_PACKAGE_SIZE);
-        if (fetchedCallback) {
-          fetchedCallback(packageData);
-          fetchedCallback = null;
-        } else {
-          fetched = packageData;
-        }
-      }\n'''
+        fetchRemotePackage(REMOTE_PACKAGE_NAME, REMOTE_PACKAGE_SIZE)
+          .then((data) => {
+            if (fetchedCallback) {
+              fetchedCallback(data);
+              fetchedCallback = null;
+            } else {
+              fetched = data;
+            }
+          })%s;
+      }\n''' % (catch_case if options.export_es6 else '')
 
       code += '''
       Module['preloadResults'][PACKAGE_NAME] = {fromCache: false};
@@ -1112,10 +1123,10 @@ def generate_js(data_target, data_files, metadata):
   ret += '''
     }
     if (Module['calledRun']) {
-      await runWithFS(Module);
+      runWithFS(Module)%s;
     } else {
       (Module['preRun'] ??= []).push(runWithFS); // FS is not initialized yet, wait for it
-    }\n'''
+    }\n''' % (catch_case if options.export_es6 else '')
 
   if options.separate_metadata:
     node_support_code = ''
@@ -1151,10 +1162,11 @@ def generate_js(data_target, data_files, metadata):
   else:
     ret += '''
     }
-    await loadPackage(%s);\n''' % json.dumps(metadata)
+    loadPackage(%s);\n''' % json.dumps(metadata)
 
   if options.export_es6:
     ret += '''
+  });
 }
 // END the loadDataFile function
 '''

From 2aa190ddb160d77a1f90b9fd15a29f6bd86626b7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C5=81ukasz=20Kwinta?=
 <33606064+lkwinta@users.noreply.github.com>
Date: Wed, 13 Aug 2025 07:34:00 +0000
Subject: [PATCH 6/6] address @sbc100 review

---
 tools/file_packager.py | 21 +++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/tools/file_packager.py b/tools/file_packager.py
index 58a7e7272c8c6..7768d7ca17862 100755
--- a/tools/file_packager.py
+++ b/tools/file_packager.py
@@ -713,8 +713,10 @@ def generate_js(data_target, data_files, metadata):
     create_data = '''// canOwn this data in the filesystem, it is a slide into the heap that will never change
           Module['FS_createDataFile'](this.name, null, byteArray, true, true, true);
           Module['removeRunDependency'](`fp ${that.name}`);'''
-    ready_promise = '''
-          loadDataResolve();'''
+
+    finish_handler = create_preloaded if options.use_preload_plugins else create_data
+    if options.export_es6:
+      finish_handler += '\nloadDataResolve();'
 
     if not options.lz4:
       # Data requests - for getting a block of data out of the big archive - have
@@ -741,14 +743,14 @@ def generate_js(data_target, data_files, metadata):
         finish: function(byteArray) {
           var that = this;
           %s
-          this.requests[this.name] = null;%s
+          this.requests[this.name] = null;
         }
       };
 
       var files = metadata['files'];
       for (var i = 0; i < files.length; ++i) {
         new DataRequest(files[i]['start'], files[i]['end'], files[i]['audio'] || 0).open('GET', files[i]['filename']);
-      }\n''' % (create_preloaded if options.use_preload_plugins else create_data, ready_promise if options.export_es6 else '')
+      }\n''' % finish_handler
 
   if options.has_embedded and not options.obj_output:
     diagnostics.warn('--obj-output is recommended when using --embed.  This outputs an object file for linking directly into your application is more efficient than JS encoding')
@@ -1051,7 +1053,10 @@ def generate_js(data_target, data_files, metadata):
 
     code += '''
       Module['preloadResults'] ??= {};\n'''
-    catch_case = '''
+
+    catch_handler = ''
+    if options.export_es6:
+      catch_handler = '''
           .catch((error) => {
             loadDataReject(error);
           })'''
@@ -1084,7 +1089,7 @@ def generate_js(data_target, data_files, metadata):
           await preloadFallback(e)%s;
         }
 
-        Module['setStatus']?.('Downloading...');\n''' % (catch_case if options.export_es6 else '')
+        Module['setStatus']?.('Downloading...');\n''' % catch_handler
     else:
       # Not using preload cache, so we might as well start the xhr ASAP,
       # potentially before JS parsing of the main codebase if it's after us.
@@ -1106,7 +1111,7 @@ def generate_js(data_target, data_files, metadata):
               fetched = data;
             }
           })%s;
-      }\n''' % (catch_case if options.export_es6 else '')
+      }\n''' % catch_handler
 
       code += '''
       Module['preloadResults'][PACKAGE_NAME] = {fromCache: false};
@@ -1126,7 +1131,7 @@ def generate_js(data_target, data_files, metadata):
       runWithFS(Module)%s;
     } else {
       (Module['preRun'] ??= []).push(runWithFS); // FS is not initialized yet, wait for it
-    }\n''' % (catch_case if options.export_es6 else '')
+    }\n''' % catch_handler
 
   if options.separate_metadata:
     node_support_code = ''