Files app: Generate main_modules.html for running as JS modules

Bug: 1133186
Change-Id: I65e1a8acdf573ce233b9d78bcdc213f12cb1109e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2639431
Auto-Submit: Luciano Pacheco <lucmult@chromium.org>
Commit-Queue: Jeremie Boulic <jboulic@chromium.org>
Reviewed-by: Jeremie Boulic <jboulic@chromium.org>
Cr-Commit-Position: refs/heads/master@{#845530}

ui/file_manager/BUILD.gn

@@ -374,6 +374,7 @@ preprocess_if_expr("preprocess_generated") {
     "//ui/file_manager/base/js:modulize",
     "//ui/file_manager/externs:modulize",
     "//ui/file_manager/externs/background:modulize",
+    "//ui/file_manager/file_manager:gen_main_html",
     "//ui/file_manager/file_manager/background/js:modulize",
     "//ui/file_manager/file_manager/common/js:modulize",
     "//ui/file_manager/file_manager/cws_widget:modulize",
@@ -408,8 +409,9 @@ generate_grd("build_grd") {
     "file_manager/foreground/elements/files_toggle_ripple.m.js",
     "file_manager/foreground/js/deferred_elements.m.rollup.js",
     "file_manager/foreground/js/main.m.rollup.js",
-    "file_manager/foreground/js/shared.m.rollup.js",
     "file_manager/foreground/js/metadata_dispatcher.m.rollup.js",
+    "file_manager/foreground/js/shared.m.rollup.js",
+    "file_manager/main_modules.html",
 
     "video_player/js/main.m.rollup.js",
     "video_player/js/main_background.m.rollup.js",

ui/file_manager/base/gn/gen_main_html.py

+# Copyright 2021 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+#
+# Lint as: python3
+
+"""Generate Files app main_modules.html based on the main.html"""
+
+from __future__ import print_function
+
+import fileinput
+import optparse
+import os
+import shutil
+import sys
+
+_MAIN = '  <script type="module" src="foreground/js/main.m.js"></script>\n'
+
+def GenerateHtml(source, target):
+  """Copy source file to target with edits, then add BUILD time stamp."""
+
+  # Copy source (main.html) file to the target (main.html) file.
+  shutil.copyfile(source, target)
+
+  # Edit the target file.
+  main_included = False
+  for line in fileinput.input(target, inplace=True):
+    # Ignore all <script> and <link rel="import">.
+    if '<script' in line or 'rel="import"' in line:
+      if main_included:
+        continue
+      else:
+        line = ''
+        sys.stdout.write(_MAIN)
+        main_included = True
+
+    sys.stdout.write(line)
+
+  # Create a BUILD time stamp for the target file.
+  open(target + '.stamp', 'a').close()
+
+def main(args):
+  parser = optparse.OptionParser()
+
+  parser.add_option('--source', help='Files app main.html source file.')
+  parser.add_option('--target', help='Target fianl main.html for output.')
+
+  options, _ = parser.parse_args(args)
+
+  if options.source and options.target:
+    GenerateHtml(options.source, options.target)
+    return
+
+  raise ValueError('Usage: all arguments are required.')
+
+if __name__ == '__main__':
+  sys.exit(main(sys.argv[1:]))
+

ui/file_manager/file_manager/BUILD.gn

@@ -4,6 +4,24 @@
 
 import("//ui/webui/resources/tools/generate_grd.gni")
 
+action("gen_main_html") {
+  inputs = [ "main.html" ]
+
+  script = "//ui/file_manager/base/gn/gen_main_html.py"
+
+  args = [
+    "--source",
+    rebase_path("//ui/file_manager/file_manager/main.html", root_build_dir),
+    "--target",
+    rebase_path("$target_gen_dir/main_modules.html", root_build_dir),
+  ]
+
+  outputs = [
+    "$target_gen_dir/main_modules.html",
+    "$target_gen_dir/main_modules.html.stamp",
+  ]
+}
+
 generated_static_grdp = "$target_gen_dir/static_resources.grdp"
 
 generate_grd("build_static_grdp") {