Add new javascript_packs_with_chunks_tag helper

CHANGELOG.md

@@ -1,5 +1,37 @@
 **Please note that Webpacker 3.1.0 and 3.1.1 have some serious bugs so please consider using either 3.0.2 or 3.2.0**
 
+## [4.0.0] - Unreleased
+
+### Fixed
+ - Issue with javascript_pack_tag asset duplication [#1898](https://github.com/rails/webpacker/pull/1898)
+
+
+### Added
+ - `javascript_packs_with_chunks_tag` helper, which creates html tags
+  for a pack and all the dependent chunks, when using splitchunks.
+
+```erb
+<%= javascript_packs_with_chunks_tag 'calendar', 'map', 'data-turbolinks-track': 'reload' %>
+
+<script src="/packs/vendor-16838bab065ae1e314.js" data-turbolinks-track="reload"></script>
+<script src="/packs/calendar~runtime-16838bab065ae1e314.js" data-turbolinks-track="reload"></script>
+<script src="/packs/calendar-1016838bab065ae1e314.js" data-turbolinks-track="reload"></script>
+<script src="/packs/map~runtime-16838bab065ae1e314.js" data-turbolinks-track="reload"></script>
+<script src="/packs/map-16838bab065ae1e314.js" data-turbolinks-track="reload"></script>
+```
+
+**Important:** Pass all your pack names when using `javascript_packs_with_chunks_tag`
+helper otherwise you will get duplicated chunks on the page.
+
+```erb
+<%# DO %>
+<%= javascript_packs_with_chunks_tag 'calendar', 'map' %>
+
+<%# DON'T %>
+<%= javascript_packs_with_chunks_tag 'calendar' %>
+<%= javascript_packs_with_chunks_tag 'map' %>
+```
+
 ## [4.0.0.rc.2] - 2018-12-15
 
 ### Fixed

README.md

@@ -142,6 +142,31 @@ can use the `asset_pack_path` helper:
 <img src="<%= asset_pack_path 'images/logo.svg' %>" />
 ```
 
+If you are using new webpack 4 split chunks API, then consider using `javascript_packs_with_chunks_tag` helper, which creates html
+tags for a pack and all the dependent chunks.
+
+```erb
+<%= javascript_packs_with_chunks_tag 'calendar', 'map', 'data-turbolinks-track': 'reload' %>
+
+<script src="/packs/vendor-16838bab065ae1e314.js" data-turbolinks-track="reload"></script>
+<script src="/packs/calendar~runtime-16838bab065ae1e314.js" data-turbolinks-track="reload"></script>
+<script src="/packs/calendar-1016838bab065ae1e314.js" data-turbolinks-track="reload"></script>
+<script src="/packs/map~runtime-16838bab065ae1e314.js" data-turbolinks-track="reload"></script>
+<script src="/packs/map-16838bab065ae1e314.js" data-turbolinks-track="reload"></script>
+```
+
+**Important:** Pass all your pack names when using `javascript_packs_with_chunks_tag`
+helper otherwise you will get duplicated chunks on the page.
+
+```erb
+<%# DO %>
+<%= javascript_packs_with_chunks_tag 'calendar', 'map' %>
+
+<%# DON'T %>
+<%= javascript_packs_with_chunks_tag 'calendar' %>
+<%= javascript_packs_with_chunks_tag 'map' %>
+```
+
 **Note:** In order for your styles or static assets files to be available in your view,
 you would need to link them in your "pack" or entry file.
 

docs/webpack.md

@@ -267,32 +267,36 @@ For the full configuration options of SplitChunks, see the [Webpack documentatio
 // config/webpack/environment.js
 const WebpackAssetsManifest = require('webpack-assets-manifest');
 
-const splitChunks = {
-  optimization: {
-    splitChunks: {
-      chunks: 'all'
-    },
-  },
-};
-
-environment.config.merge(splitChunks);
-
-// Should override the existing manifest plugin
-environment.plugins.insert(
-  'Manifest',
-  new WebpackAssetsManifest({
-    entrypoints: true, // default in rails is false
-    writeToDisk: true, // rails defaults copied from webpacker
-    publicPath: true // rails defaults copied from webpacker
-  })
-)
+// Enable the default config
+environment.splitChunks()
+
+// or using custom config
+environment.splitChunks((config) => Object.assign({}, config, { optimization: { splitChunks: false }}))
 ```
 
-To use the `javascript_pack_tag` or the `stylesheet_pack_tag` with `SplitChunks` or `RuntimeChunks` you can refer to the packs as usual.
+Then use, `javascript_packs_with_chunks_tag` helper to include all the transpiled
+packs with the chunks in your view, which creates html tags for all the chunks.
 
 ```erb
-javascript_pack_tag "your-entrypoint-javascript-file"
-stylesheet_pack_tag "your-entrypoint-stylesheet-file"
+<%= javascript_packs_with_chunks_tag 'calendar', 'map', 'data-turbolinks-track': 'reload' %>
+
+<script src="/packs/vendor-16838bab065ae1e314.js" data-turbolinks-track="reload"></script>
+<script src="/packs/calendar~runtime-16838bab065ae1e314.js" data-turbolinks-track="reload"></script>
+<script src="/packs/calendar-1016838bab065ae1e314.js" data-turbolinks-track="reload"></script>
+<script src="/packs/map~runtime-16838bab065ae1e314.js" data-turbolinks-track="reload"></script>
+<script src="/packs/map-16838bab065ae1e314.js" data-turbolinks-track="reload"></script>
+```
+
+**Important:** Pass all your pack names when using this helper otherwise you will
+get duplicated chunks on the page.
+
+```erb
+<%# DO %>
+<%= javascript_packs_with_chunks_tag 'calendar', 'map' %>
+
+<%# DON'T %>
+<%= javascript_packs_with_chunks_tag 'calendar' %>
+<%= javascript_packs_with_chunks_tag 'map' %>
 ```
 
 For the old configuration with the CommonsChunkPlugin see below. **Note** that this functionality is deprecated in Webpack V4.

lib/webpacker/helper.rb

@@ -59,7 +59,29 @@ def image_pack_tag(name, **options)
   #   <%= javascript_pack_tag 'calendar', 'data-turbolinks-track': 'reload' %> # =>
   #   <script src="/packs/calendar-1016838bab065ae1e314.js" data-turbolinks-track="reload"></script>
   def javascript_pack_tag(*names, **options)
-    javascript_include_tag(*sources_from_pack_manifest(names, type: :javascript), **options)
+    javascript_include_tag(*sources_from_manifest_entries(names, type: :javascript), **options)
+  end
+
+  # Creates script tags that references the chunks from entrypoints when using split chunks API,
+  # as compiled by webpack per the entries list in config/webpack/shared.js.
+  # By default, this list is auto-generated to match everything in
+  # app/javascript/packs/*.js and all the dependent chunks. In production mode, the digested reference is automatically looked up.
+  # See: https://webpack.js.org/plugins/split-chunks-plugin/
+  # Example:
+  #
+  #   <%= javascript_packs_with_chunks_tag 'calendar', 'map', 'data-turbolinks-track': 'reload' %> # =>
+  #   <script src="/packs/vendor-16838bab065ae1e314.js" data-turbolinks-track="reload"></script>
+  #   <script src="/packs/calendar~runtime-16838bab065ae1e314.js" data-turbolinks-track="reload"></script>
+  #   <script src="/packs/calendar-1016838bab065ae1e314.js" data-turbolinks-track="reload"></script>
+  #   <script src="/packs/map~runtime-16838bab065ae1e314.js" data-turbolinks-track="reload"></script>
+  #   <script src="/packs/map-16838bab065ae1e314.js" data-turbolinks-track="reload"></script>
+  # DO:
+  # <%= javascript_packs_with_chunks_tag 'calendar', 'map' %>
+  # DON'T:
+  # <%= javascript_packs_with_chunks_tag 'calendar' %>
+  # <%= javascript_packs_with_chunks_tag 'map' %>
+  def javascript_packs_with_chunks_tag(*names, **options)
+    javascript_include_tag(*sources_from_manifest_entrypoints(names, type: :javascript), **options)
   end
 
   # Creates a link tag that references the named pack file, as compiled by webpack per the entries list
@@ -80,7 +102,7 @@ def javascript_pack_tag(*names, **options)
   #   <link rel="stylesheet" media="screen" href="/packs/calendar-1016838bab065ae1e122.css" data-turbolinks-track="reload" />
   def stylesheet_pack_tag(*names, **options)
     if current_webpacker_instance.config.extract_css?
-      stylesheet_link_tag(*sources_from_pack_manifest(names, type: :stylesheet), **options)
+      stylesheet_link_tag(*sources_from_manifest_entries(names, type: :stylesheet), **options)
     end
   end
 
@@ -89,7 +111,11 @@ def stylesheet?(name)
       File.extname(name) == ".css"
     end
 
-    def sources_from_pack_manifest(names, type:)
+    def sources_from_manifest_entries(names, type:)
       names.map { |name| current_webpacker_instance.manifest.lookup!(name, type: type) }.flatten
     end
+
+    def sources_from_manifest_entrypoints(names, type:)
+      names.map { |name| current_webpacker_instance.manifest.lookup_pack_with_chunks!(name, type: type) }.flatten.uniq
+    end
 end

lib/webpacker/manifest.rb

@@ -18,6 +18,20 @@ def refresh
     @data = load
   end
 
+  def lookup_pack_with_chunks(name, pack_type = {})
+    compile if compiling?
+
+    manifest_pack_type = manifest_type(pack_type[:type])
+    manifest_pack_name = manifest_name(name, manifest_pack_type)
+    find("entrypoints")[manifest_pack_name][manifest_pack_type]
+  rescue NoMethodError
+    nil
+  end
+
+  def lookup_pack_with_chunks!(name, pack_type = {})
+    lookup_pack_with_chunks(name, pack_type) || handle_missing_entry(name)
+  end
+
   # Computes the relative path for a given Webpacker asset using manifest.json.
   # If no asset is found, returns nil.
   #
@@ -27,22 +41,7 @@ def refresh
   def lookup(name, pack_type = {})
     compile if compiling?
 
-    # When using SplitChunks or RuntimeChunks the manifest hash will contain
-    # an extra object called "entrypoints". When the entrypoints key is not
-    # present in the manifest, or the name is not found in the entrypoints hash,
-    # it will raise a NoMethodError. If this happens, we should try to lookup
-    # a single instance of the pack based on the given name.
-    begin
-      manifest_pack_type = manifest_type(pack_type[:type])
-      manifest_pack_name = manifest_name(name, manifest_pack_type)
-
-      # Lookup the pack in the entrypoints of the manifest
-      find("entrypoints")[manifest_pack_name][manifest_pack_type]
-    rescue NoMethodError
-
-      # Lookup a single instance of the pack
-      find(full_pack_name(name, pack_type[:type]))
-    end
+    find(full_pack_name(name, pack_type[:type]))
   end
 
   # Like lookup, except that if no asset is found, raises a Webpacker::Manifest::MissingEntryError.

package/environments/development.js

@@ -9,7 +9,6 @@ module.exports = class extends Base {
 
     if (devServer.hmr) {
       this.plugins.append('HotModuleReplacement', new webpack.HotModuleReplacementPlugin())
-      this.plugins.append('NamedModules', new webpack.NamedModulesPlugin())
       this.config.output.filename = '[name]-[hash].js'
     }
 

test/helper_test.rb

@@ -64,7 +64,7 @@ def test_javascript_pack_tag_split_chunks
       %(<script src="/packs/vendors~application~bootstrap-c20632e7baf2c81200d3.chunk.js"></script>\n) +
         %(<script src="/packs/vendors~application-e55f2aae30c07fb6d82a.chunk.js"></script>\n) +
         %(<script src="/packs/application-k344a6d59eef8632c9d1.js"></script>),
-      javascript_pack_tag("application")
+      javascript_packs_with_chunks_tag("application")
   end
 
   def test_stylesheet_pack_tag

test/manifest_test.rb

@@ -22,6 +22,10 @@ def test_lookup_nil
     assert_nil Webpacker.manifest.lookup("foo.js")
   end
 
+  def test_lookup_chunks_nil
+    assert_nil Webpacker.manifest.lookup_pack_with_chunks("foo.js")
+  end
+
   def test_lookup_success
     assert_equal Webpacker.manifest.lookup("bootstrap.js"), "/packs/bootstrap-300631c4f0e0f9c865bc.js"
   end
@@ -33,6 +37,6 @@ def test_lookup_entrypoint
       "/packs/application-k344a6d59eef8632c9d1.js"
     ]
 
-    assert_equal Webpacker.manifest.lookup!("application", type: :javascript), application_entrypoints
+    assert_equal Webpacker.manifest.lookup_pack_with_chunks!("application", type: :javascript), application_entrypoints
   end
 end