Enforce presence of licensing info for npm modules (fixes brave/brave…

…-browser#6857)

.github/CODEOWNERS

@@ -48,8 +48,8 @@ components/brave_wayback_machine @simonhong
 
 # Licensing of third-party components
 common/licenses/ @fmarier
-components/third_party/ @fmarier
 script/brave_license_helper.py @fmarier
+script/check_npm_licenses.py @fmarier
 script/generate_licenses.py @fmarier
 
 # Crypto Wallets

components/resources/BUILD.gn

@@ -97,3 +97,15 @@ grit("strings") {
   output_dir = "$root_gen_dir/components"
   resource_ids = "//brave/browser/resources/resource_ids"
 }
+
+action("about_credits") {
+  script = "//brave/script/check_npm_licenses.py"
+
+  inputs = [ "//brave/package.json" ]
+
+  outputs = [ "$root_gen_dir/npm_licenses.checked" ]
+
+  args = [
+    rebase_path("$root_gen_dir/npm_licenses.checked")
+  ]
+}

patches/components-resources-BUILD.gn.patch

@@ -0,0 +1,12 @@
+diff --git a/components/resources/BUILD.gn b/components/resources/BUILD.gn
+index d1645a13a358b64cefb80cfe1c8f0691a68e3204..8e07af1390e9d1a5999aa543e6537f5daa8b096b 100644
+--- a/components/resources/BUILD.gn
++++ b/components/resources/BUILD.gn
+@@ -73,6 +73,7 @@ grit("components_scaled_resources") {
+ }
+
+ action("about_credits") {
++  deps = [ "//brave/components/resources:about_credits" ]
+   script = "//tools/licenses.py"
+   depfile = "$target_gen_dir/$target_name.d"
+

script/check_npm_licenses.py

@@ -0,0 +1,57 @@
+#!/usr/bin/env python3
+# Copyright (c) 2020 The Brave Authors. All rights reserved.
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this file,
+# You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+import argparse
+import json
+import os
+import sys
+
+from lib.config import SOURCE_ROOT
+
+
+EXCLUSIONS = [
+    # Already covered by brave/third_party/npm-types
+    '@types/jszip',
+    '@types/parse-torrent',
+    '@types/webtorrent',
+]
+
+
+def check_dependency(module_name):
+    if module_name in EXCLUSIONS:
+        return True
+
+    third_party_dir = os.path.join(os.path.dirname(SOURCE_ROOT), 'brave', 'third_party')
+    readme_path = os.path.join(third_party_dir, 'npm_%s' % module_name, 'README.chromium')
+    if not os.path.isfile(readme_path):
+        print('npm module %s needs licensing information in %s' % (module_name, readme_path))
+        return False
+
+    return True
+
+
+def main():
+    parser = argparse.ArgumentParser()
+    parser.add_argument('output_file', nargs='?')
+    args = parser.parse_args()
+
+    return_code = 0
+    package_json = os.path.join(os.path.dirname(SOURCE_ROOT), 'brave', 'package.json')
+    with open(package_json) as file_handle:
+        dependencies = json.loads(file_handle.read())["dependencies"]
+        for module_name in dependencies:
+            if not check_dependency(module_name):
+                return_code = 1
+
+    if args.output_file:
+        with open(args.output_file, 'wt') as file_handle:
+            file_handle.write('')
+
+    return return_code
+
+
+if __name__ == '__main__':
+    sys.exit(main())