Use consistent helper for tests that use -sMODULARIZE (emscripten-core#22537)

As part of this I also extended the `#preprocess` directive so it can be
used with `--extern-pre-js` and `--extern-post-js` as well as the
existing supprot for `--pre-js` and `--post-js`.

Author: sbc100

test/modularize_post_js.js

@@ -0,0 +1,10 @@
+#preprocess
+
+// This file gets included via `--extern-post-js` in order to run tests
+// that are built with `-sMODULARIZE`.
+
+#if PTHREADS
+// Avoid instantiating the module on pthreads.
+if (!isPthread)
+#endif
+{{{ EXPORT_NAME }}}();

test/runner.py

@@ -114,7 +114,7 @@ def check_js_engines():
 
 def get_and_import_modules():
   modules = []
-  for filename in glob.glob(os.path.join(os.path.dirname(__file__), 'test*.py')):
+  for filename in glob.glob(os.path.join(common.TEST_ROOT, 'test*.py')):
     module_dir, module_file = os.path.split(filename)
     module_name, module_ext = os.path.splitext(module_file)
     __import__(module_name)

test/test_core.py

@@ -2468,10 +2468,7 @@ def test_pthread_proxying(self, modularize):
     if modularize:
       self.set_setting('MODULARIZE')
       self.set_setting('EXPORT_NAME=ModuleFactory')
-      # Only instantiate the module on the main thread.
-      create_file('extern-post.js',
-                  'if (typeof importScripts != "function") ModuleFactory();')
-      args = ['--extern-post-js=extern-post.js']
+      args = ['--extern-post-js', test_file('modularize_post_js.js')]
     self.do_run_in_out_file_test('pthread/test_pthread_proxying.c',
                                  interleaved_output=False, emcc_args=args)
 
@@ -6266,8 +6263,7 @@ def test_unicode_js_library(self):
     err = self.expect_fail([PYTHON, 'expect_fail.py'], expect_traceback=True)
     self.assertContained('UnicodeDecodeError', err)
 
-    create_file('modularize_post.js', '(async function main(){await Module();})()')
-    self.emcc_args += ['-sMODULARIZE', '--js-library', test_file('unicode_library.js'), '--extern-post-js', 'modularize_post.js', '--post-js', test_file('unicode_postjs.js')]
+    self.emcc_args += ['-sMODULARIZE', '--js-library', test_file('unicode_library.js'), '--extern-post-js', test_file('modularize_post_js.js'), '--post-js', test_file('unicode_postjs.js')]
     self.do_run_in_out_file_test('test_unicode_js_library.c')
 
   def test_funcptr_import_type(self):
@@ -7924,14 +7920,13 @@ def get_wat_addr(call_index):
   def test_modularize_closure_pre(self):
     # test that the combination of modularize + closure + pre-js works. in that mode,
     # closure should not minify the Module object in a way that the pre-js cannot use it.
-    create_file('post.js', 'var TheModule = Module();\n')
     if self.is_wasm2js():
       # TODO(sbc): Fix closure warnings with MODULARIZE + WASM=0
       self.ldflags.append('-Wno-error=closure')
 
     self.emcc_args += [
       '--pre-js', test_file('core/modularize_closure_pre.js'),
-      '--extern-post-js=post.js',
+      '--extern-post-js', test_file('modularize_post_js.js'),
       '--closure=1',
       '-g1',
       '-sMODULARIZE',
@@ -9222,8 +9217,7 @@ def test_pthread_offset_converter_modularize(self):
     self.set_setting('USE_OFFSET_CONVERTER')
     self.set_setting('MODULARIZE')
     self.set_setting('EXPORT_NAME', 'foo')
-    create_file('post.js', 'if (!isPthread) foo();')
-    self.emcc_args += ['--extern-post-js', 'post.js']
+    self.emcc_args += ['--extern-post-js', test_file('modularize_post_js.js')]
     if '-g' in self.emcc_args:
       self.emcc_args += ['-DDEBUG']
     self.do_runf('core/test_return_address.c', 'passed')

test/test_other.py

@@ -349,9 +349,8 @@ def test_emcc_generate_config(self, compiler):
     'node': (['-sENVIRONMENT=node'],),
   })
   def test_emcc_output_mjs(self, args):
-    create_file('extern-post.js', 'await Module();')
     self.run_process([EMCC, '-o', 'hello_world.mjs',
-                      '--extern-post-js', 'extern-post.js',
+                      '--extern-post-js', test_file('modularize_post_js.js'),
                       test_file('hello_world.c')] + args)
     src = read_file('hello_world.mjs')
     self.assertContained('export default Module;', src)
@@ -363,11 +362,10 @@ def test_emcc_output_mjs(self, args):
   })
   @node_pthreads
   def test_emcc_output_worker_mjs(self, args):
-    create_file('extern-post.js', 'if (!isPthread) await Module();')
     os.mkdir('subdir')
     self.run_process([EMCC, '-o', 'subdir/hello_world.mjs',
                       '-sEXIT_RUNTIME', '-sPROXY_TO_PTHREAD', '-pthread', '-O1',
-                      '--extern-post-js', 'extern-post.js',
+                      '--extern-post-js', test_file('modularize_post_js.js'),
                       test_file('hello_world.c')] + args)
     src = read_file('subdir/hello_world.mjs')
     self.assertContained("new URL('hello_world.wasm', import.meta.url)", src)
@@ -377,19 +375,17 @@ def test_emcc_output_worker_mjs(self, args):
 
   @node_pthreads
   def test_emcc_output_worker_mjs_single_file(self):
-    create_file('extern-post.js', 'await Module();')
     self.run_process([EMCC, '-o', 'hello_world.mjs', '-pthread',
-                     '--extern-post-js', 'extern-post.js',
+                      '--extern-post-js', test_file('modularize_post_js.js'),
                       test_file('hello_world.c'), '-sSINGLE_FILE'])
     src = read_file('hello_world.mjs')
     self.assertNotContained("new URL('data:", src)
     self.assertContained("new Worker(new URL('hello_world.mjs', import.meta.url), workerOptions)", src)
     self.assertContained('hello, world!', self.run_js('hello_world.mjs'))
 
   def test_emcc_output_mjs_closure(self):
-    create_file('extern-post.js', 'await Module();')
     self.run_process([EMCC, '-o', 'hello_world.mjs',
-                      '--extern-post-js', 'extern-post.js',
+                      '--extern-post-js', test_file('modularize_post_js.js'),
                       test_file('hello_world.c'), '--closure=1'])
     src = read_file('hello_world.mjs')
     self.assertContained('new URL("hello_world.wasm", import.meta.url)', src)
@@ -1577,25 +1573,20 @@ def test_minimal_modularize_export_keepalive(self):
       EMSCRIPTEN_KEEPALIVE int libf1() { return 42; }
     ''')
 
-    def write_js_main():
-      """
-      With MINIMAL_RUNTIME, the module instantiation function isn't exported neither as a UMD nor as an ES6 module.
-      Thus, it's impossible to use `require` or `import`.
-
-      This function simply appends the instantiation code to the generated code.
-      """
-      runtime = read_file('test.js')
-      write_file('main.js', f'{runtime}\nModule().then((mod) => console.log(mod._libf1()));')
+    # With MINIMAL_RUNTIME, the module instantiation function isn't exported neither as a UMD nor as
+    # an ES6 module.
+    # Thus, it's impossible to use `require` or `import` and instead run the module
+    # as part of --extern-post-js.
+    create_file('post.js', 'Module().then((mod) => console.log(mod._libf1()));')
+    self.emcc_args += ['--extern-post-js=post.js']
 
     # By default, no symbols should be exported when using MINIMAL_RUNTIME.
-    self.emcc('main.c', [], output_filename='test.js')
-    write_js_main()
-    self.assertContained('TypeError: mod._libf1 is not a function', self.run_js('main.js', assert_returncode=NON_ZERO))
+    self.emcc('main.c', [])
+    self.assertContained('TypeError: mod._libf1 is not a function', self.run_js('a.out.js', assert_returncode=NON_ZERO))
 
     # Ensures that EXPORT_KEEPALIVE=1 exports the symbols.
-    self.emcc('main.c', ['-sEXPORT_KEEPALIVE=1'], output_filename='test.js')
-    write_js_main()
-    self.assertContained('42\n', self.run_js('main.js'))
+    self.emcc('main.c', ['-sEXPORT_KEEPALIVE=1'])
+    self.assertContained('42\n', self.run_js('a.out.js'))
 
   @crossplatform
   def test_minimal_runtime_export_all_modularize(self):
@@ -6682,7 +6673,12 @@ def test_define_modularize(self):
     create_file('a.out.js', src)
     self.assertContained("define([], () => Module);", src)
 
-    create_file('run_module.js', 'var m; (global.define = (deps, factory) => { m = factory(); }).amd = true; require("./a.out.js"); m();')
+    create_file('run_module.js', '''
+var m;
+(global.define = (deps, factory) => { m = factory(); }).amd = true;
+require("./a.out.js");
+m();
+''')
     output = self.run_js('run_module.js')
     self.assertContained('hello, world!\n', output)
 
@@ -10385,15 +10381,15 @@ def test_node_js_pthread_module(self, es6):
       create_file('moduleLoader.mjs', '''
         import test_module from "./subdir/module.mjs";
         test_module().then((test_module_instance) => {
-          test_module_instance._main();
+          console.log("done");
         });
         ''')
     else:
       ext = '.js'
       create_file('moduleLoader.js', '''
         const test_module = require("./subdir/module.js");
         test_module().then((test_module_instance) => {
-          test_module_instance._main();
+          console.log("done");
         });
         ''')
     ensure_dir('subdir')
@@ -10403,7 +10399,7 @@ def test_node_js_pthread_module(self, es6):
 
     # run the module
     ret = self.run_js('moduleLoader' + ext)
-    self.assertContained('hello, world!', ret)
+    self.assertContained('hello, world!\ndone\n', ret)
 
     create_file('workerLoader.js', f'''
       const {{ Worker, isMainThread }} = require('worker_threads');
@@ -10412,7 +10408,7 @@ def test_node_js_pthread_module(self, es6):
 
     # run the same module, but inside of a worker
     ret = self.run_js('workerLoader.js')
-    self.assertContained('hello, world!', ret)
+    self.assertContained('hello, world!\ndone\n', ret)
 
   @no_windows('node system() does not seem to work, see https://github.com/emscripten-core/emscripten/pull/10547')
   @requires_node
@@ -12180,15 +12176,14 @@ def test_standalone_syscalls(self):
       self.assertContained(expected, self.run_js('test.wasm', engine))
 
   @parameterized({
-    'wasm2js': (['-sWASM=0'], ''),
-    'modularize': (['-sMODULARIZE'], 'Module()'),
+    'wasm2js': (['-sWASM=0'],),
+    'modularize': (['-sMODULARIZE', '--extern-post-js', test_file('modularize_post_js.js')],),
   })
-  def test_promise_polyfill(self, constant_args, extern_post_js):
+  def test_promise_polyfill(self, constant_args):
     def test(args, expect_fail):
       # legacy browsers may lack Promise, which wasm2js depends on. see what
       # happens when we kill the global Promise function.
-      create_file('extern-post.js', extern_post_js)
-      self.run_process([EMCC, test_file('hello_world.c')] + constant_args + args + ['--extern-post-js', 'extern-post.js'])
+      self.run_process([EMCC, test_file('hello_world.c')] + constant_args + args)
       js = read_file('a.out.js')
       create_file('a.out.js', 'Promise = undefined;\n' + js)
       return self.run_js('a.out.js', assert_returncode=NON_ZERO if expect_fail else 0)

tools/link.py

@@ -301,7 +301,14 @@ def fix_windows_newlines(text):
 
 
 def read_js_files(files):
-  contents = '\n'.join(read_file(f) for f in files)
+  contents = []
+  for f in files:
+    content = read_file(f)
+    if content.startswith('#preprocess\n'):
+      contents.append(shared.read_and_preprocess(f, expand_macros=True))
+    else:
+      contents.append(content)
+  contents = '\n'.join(contents)
   return fix_windows_newlines(contents)