Honor output-eol, even in SINGLE_FILE mode (#24505)

I traced the exclusion of this file from EOL conversion all the way back
to 4c669e4. It seems like maybe there was a fear the EOL conversion
might break the base64 encoded data? But IIUC EOL chars cannot appear in
a base64 encoded string.

Fixes: #24488

Author: sbc100

test/test_other.py

@@ -9001,14 +9001,23 @@ def test_disable_inlining(self):
   @parameterized({
     '': ([],),
     'proxy_to_worker': (['--proxy-to-worker'],),
+    'single_file': (['-sSINGLE_FILE'],),
     'proxy_to_worker_wasm2js': (['--proxy-to-worker', '-sWASM=0'],),
   })
   def test_output_eol(self, params):
     for eol in ('windows', 'linux'):
       self.clear()
       print('checking eol: ', eol)
-      self.run_process([EMCC, test_file('hello_world.c'), '-o', 'a.html', '--output-eol', eol] + params)
-      for f in ['a.html', 'a.js']:
+      if '-sSINGLE_FILE' not in params:
+        params.append('-oa.out.html')
+      self.run_process([EMCC, test_file('hello_world.c'), '--output-eol', eol] + params)
+      out_files = ['a.out.js']
+      html_file = 'a.out.html'
+      if '-sSINGLE_FILE' in params:
+        self.assertNotExists(html_file)
+      else:
+        out_files.append(html_file)
+      for f in out_files:
         self.assertExists(f)
         if eol == 'linux':
           expected_ending = '\n'

tools/link.py

@@ -2248,6 +2248,8 @@ def phase_final_emitting(options, target, js_target, wasm_target):
 
   target_basename = unsuffixed_basename(target)
 
+  utils.convert_line_endings_in_file(js_target, options.output_eol)
+
   # If we were asked to also generate HTML, do that
   if options.oformat == OFormat.HTML:
     generate_html(target, options, js_target, target_basename,
@@ -2259,9 +2261,6 @@ def phase_final_emitting(options, target, js_target, wasm_target):
     diagnostics.warning('experimental', 'the SPLIT_MODULE setting is experimental and subject to change')
     do_split_module(wasm_target, options)
 
-  if not settings.SINGLE_FILE:
-    utils.convert_line_endings_in_file(js_target, options.output_eol)
-
   if options.executable:
     make_js_executable(js_target)
 

tools/utils.py

@@ -49,6 +49,7 @@ def removeprefix(string, prefix):
 
 def convert_line_endings_in_file(filename, to_eol):
   if to_eol == os.linesep:
+    assert os.path.exists(filename)
     return # No conversion needed
 
   text = read_file(filename)