Paver runs Webpack (incl watcher) in dev and test

common/static/common/js/karma.common.conf.js

@@ -189,7 +189,11 @@ function normalizePathsForCoverage(files, normalizeFunc, preprocessors) {
     files.forEach(function(file) {
         if (!file.ignoreCoverage) {
             normalizedFile = normalizeFn(appRoot, file.pattern);
-            filesForCoverage[normalizedFile] = ['coverage'].concat(preprocessors[normalizedFile] || []);
+            if (preprocessors && preprocessors.hasOwnProperty(normalizedFile)) {
+                filesForCoverage[normalizedFile] = ['coverage'].concat(preprocessors[normalizedFile]);
+            } else {
+                filesForCoverage[normalizedFile] = ['coverage'];
+            }
         }
     });
 
@@ -346,7 +350,13 @@ function getBaseConfig(config, useRequireJs) {
             captureConsole: false
         },
 
-        webpack: webpackConfig
+        webpack: webpackConfig,
+
+        webpackMiddleware: {
+            watchOptions: {
+                poll: true
+            }
+        }
     };
 }
 

lms/static/lms/js/build.js

@@ -18,8 +18,7 @@
          * done.
          */
         modules: getModulesList([
-            'course_bookmarks/js/course_bookmarks_factory',
-            'course_experience/js/course_outline_factory',
+            'course_bookmarks/js/course_bookmarks_factory',,
             'discussion/js/discussion_board_factory',
             'discussion/js/discussion_profile_page_factory',
             'js/api_admin/catalog_preview_factory',

openedx/features/course_experience/static/course_experience/js/CourseOutline.js

@@ -22,7 +22,7 @@ export class CourseOutline {  // eslint-disable-line import/prefer-default-expor
       }
     }));
 
-    document.querySelectorAll('a:not([href^="#"])')
+    [...document.querySelectorAll('a:not([href^="#"])')]
       .forEach(link => link.addEventListener('click', (event) => {
         Logger.log(
           'edx.ui.lms.link_clicked',

pavelib/assets.py

@@ -19,6 +19,7 @@ from watchdog.events import PatternMatchingEventHandler
 from .utils.envs import Env
 from .utils.cmd import cmd, django_cmd
 from .utils.timer import timed
+from .utils.process import run_background_process
 
 from openedx.core.djangoapps.theming.paver_helpers import get_theme_paths
 
@@ -703,6 +704,16 @@ def execute_compile_sass(args):
         )
 
 
+@task
+@no_help
+def execute_webpack():
+    sh(cmd("$(npm bin)/webpack"))
+
+
+def execute_webpack_watch():
+    run_background_process("$(npm bin)/webpack --watch --watch-poll=200")
+
+
 def get_parsed_option(command_opts, opt_key, default=None):
     """
     Extract user command option and parse it.
@@ -769,6 +780,11 @@ def watch_assets(options):
 
     print("Starting asset watcher...")
     observer.start()
+
+    # We only want Webpack to re-run on changes to its own entry points, not all JS files, so we use its own watcher
+    # instead of subclassing from Watchdog like the other watchers do
+    execute_webpack_watch()
+
     if not getattr(options, 'background', False):
         # when running as a separate process, the main thread needs to loop
         # in order to allow for shutdown by contrl-c
@@ -829,6 +845,7 @@ def update_assets(args):
     process_xmodule_assets()
     process_npm_assets()
     compile_coffeescript()
+    execute_webpack()
 
     # Compile sass for themes and system
     execute_compile_sass(args)

pavelib/paver_tests/test_servers.py

@@ -40,6 +40,9 @@ EXPECTED_RUN_SERVER_COMMAND = (
 EXPECTED_INDEX_COURSE_COMMAND = (
     u"python manage.py {system} --settings={settings} reindex_course --setup"
 )
+EXPECTED_WEBPACK_COMMAND = (
+    u"$(npm bin)/webpack"
+)
 
 
 @ddt.ddt
@@ -233,6 +236,7 @@ class TestPaverServerTasks(PaverTestCase):
             expected_messages.append(u"xmodule_assets common/static/xmodule")
             expected_messages.append(u"install npm_assets")
             expected_messages.append(EXPECTED_COFFEE_COMMAND.format(platform_root=self.platform_root))
+            expected_messages.append(EXPECTED_WEBPACK_COMMAND)
             expected_messages.extend(self.expected_sass_commands(system=system, asset_settings=expected_asset_settings))
         if expected_collect_static:
             expected_messages.append(EXPECTED_COLLECT_STATIC_COMMAND.format(
@@ -270,6 +274,7 @@ class TestPaverServerTasks(PaverTestCase):
             expected_messages.append(u"xmodule_assets common/static/xmodule")
             expected_messages.append(u"install npm_assets")
             expected_messages.append(EXPECTED_COFFEE_COMMAND.format(platform_root=self.platform_root))
+            expected_messages.append(EXPECTED_WEBPACK_COMMAND)
             expected_messages.extend(self.expected_sass_commands(asset_settings=expected_asset_settings))
         if expected_collect_static:
             expected_messages.append(EXPECTED_COLLECT_STATIC_COMMAND.format(

webpack.config.js

@@ -45,6 +45,10 @@ var wpconfig = {
 
     resolve: {
         extensions: ['.js', '.json']
+    },
+
+    watchOptions: {
+        poll: true
     }
 };