Allow multiple importmaps in config/importmaps/

app/helpers/importmap/importmap_tags_helper.rb

@@ -1,16 +1,18 @@
 module Importmap::ImportmapTagsHelper
   # Setup all script tags needed to use an importmap-powered entrypoint (which defaults to application.js)
-  def javascript_importmap_tags(entry_point = "application", importmap: Rails.application.importmap)
+  def javascript_importmap_tags(entry_point = "application", importmap_name = "application")
     safe_join [
-      javascript_inline_importmap_tag(importmap.to_json(resolver: self)),
-      javascript_importmap_module_preload_tags(importmap),
+      javascript_inline_importmap_tag(importmap_name),
+      javascript_importmap_module_preload_tags(importmap_name),
       javascript_import_module_tag(entry_point)
     ], "\n"
   end
 
   # Generate an inline importmap tag using the passed `importmap_json` JSON string.
   # By default, `Rails.application.importmap.to_json(resolver: self)` is used.
-  def javascript_inline_importmap_tag(importmap_json = Rails.application.importmap.to_json(resolver: self))
+  def javascript_inline_importmap_tag(importmap_name = "application")
+    importmap = Rails.application.importmaps.fetch(importmap_name.to_s)
+    importmap_json = importmap.to_json(resolver: self)
     tag.script importmap_json.html_safe,
       type: "importmap", "data-turbo-track": "reload", nonce: request&.content_security_policy_nonce
   end
@@ -24,7 +26,8 @@ def javascript_import_module_tag(*module_names)
   # Link tags for preloading all modules marked as preload: true in the `importmap`
   # (defaults to Rails.application.importmap), such that they'll be fetched
   # in advance by browsers supporting this link type (https://caniuse.com/?search=modulepreload).
-  def javascript_importmap_module_preload_tags(importmap = Rails.application.importmap)
+  def javascript_importmap_module_preload_tags(importmap_name = "application")
+    importmap = Rails.application.importmaps.fetch(importmap_name.to_s)
     javascript_module_preload_tag(*importmap.preloaded_module_paths(resolver: self))
   end
 

gemfiles/rails_main_propshaft.gemfile

@@ -3,7 +3,7 @@
 source "https://rubygems.org"
 
 gem "rails", branch: "main", git: "https://github.com/rails/rails.git"
-gem "sqlite3", "~> 1.4"
+gem "sqlite3", "~> 2.0"
 gem "propshaft"
 
 group :development do

gemfiles/rails_main_sprockets.gemfile

@@ -3,7 +3,7 @@
 source "https://rubygems.org"
 
 gem "rails", branch: "main", git: "https://github.com/rails/rails.git"
-gem "sqlite3", "~> 1.4"
+gem "sqlite3", "~> 2.0"
 gem "sprockets-rails"
 
 group :development do

lib/importmap/commands.rb

@@ -12,17 +12,20 @@ def self.exit_on_failure?
   desc "pin [*PACKAGES]", "Pin new packages"
   option :env, type: :string, aliases: :e, default: "production"
   option :from, type: :string, aliases: :f, default: "jspm"
+  option :importmap, type: :string, aliases: :i, default: "application"
   def pin(*packages)
+    packager = Importmap::Packager.new(options[:importmap])
+
     if imports = packager.import(*packages, env: options[:env], from: options[:from])
       imports.each do |package, url|
-        puts %(Pinning "#{package}" to #{packager.vendor_path}/#{package}.js via download from #{url})
+        puts %(Pinning "#{package}" to #{packager.vendor_path}/#{package}.js via download from #{url} in importmap "#{options[:importmap]}")
         packager.download(package, url)
         pin = packager.vendored_pin_for(package, url)
 
         if packager.packaged?(package)
-          gsub_file("config/importmap.rb", /^pin "#{package}".*$/, pin, verbose: false)
+          gsub_file(packager.importmap_path, /^pin "#{package}".*$/, pin, verbose: false)
         else
-          append_to_file("config/importmap.rb", "#{pin}\n", verbose: false)
+          append_to_file(packager.importmap_path, "#{pin}\n", verbose: false)
         end
       end
     else
@@ -33,7 +36,10 @@ def pin(*packages)
   desc "unpin [*PACKAGES]", "Unpin existing packages"
   option :env, type: :string, aliases: :e, default: "production"
   option :from, type: :string, aliases: :f, default: "jspm"
+  option :importmap, type: :string, aliases: :i, default: "application"
   def unpin(*packages)
+    packager = Importmap::Packager.new(options[:importmap])
+
     if imports = packager.import(*packages, env: options[:env], from: options[:from])
       imports.each do |package, url|
         if packager.packaged?(package)
@@ -47,9 +53,10 @@ def unpin(*packages)
   end
 
   desc "json", "Show the full importmap in json"
+  option :importmap, type: :string, aliases: :i, default: "application"
   def json
     require Rails.root.join("config/environment")
-    puts Rails.application.importmap.to_json(resolver: ActionController::Base.helpers)
+    puts Rails.application.importmaps[options[:importmap]].to_json(resolver: ActionController::Base.helpers)
   end
 
   desc "audit", "Run a security audit"
@@ -104,10 +111,6 @@ def packages
   end
 
   private
-    def packager
-      @packager ||= Importmap::Packager.new
-    end
-
     def npm
       @npm ||= Importmap::Npm.new
     end

lib/importmap/engine.rb

@@ -1,7 +1,7 @@
 require "importmap/map"
 
-# Use Rails.application.importmap to access the map
-Rails::Application.send(:attr_accessor, :importmap)
+# Use Rails.application.importmaps to access the maps
+Rails::Application.send(:attr_accessor, :importmaps)
 
 module Importmap
   class Engine < ::Rails::Engine
@@ -14,9 +14,20 @@ class Engine < ::Rails::Engine
     config.autoload_once_paths = %W( #{root}/app/helpers )
 
     initializer "importmap" do |app|
-      app.importmap = Importmap::Map.new
+      importmap = Importmap::Map.new
+      app.importmaps = {
+        "application" => importmap
+      }
       app.config.importmap.paths << app.root.join("config/importmap.rb")
-      app.config.importmap.paths.each { |path| app.importmap.draw(path) }
+      app.config.importmap.paths.each { |path| importmap.draw(path) }
+
+      Dir[app.root.join("config/importmaps/*.rb")].each do |path|
+        namespace = File.basename(path).delete_suffix(".rb")
+        importmap = Importmap::Map.new
+        app.config.importmap.paths.each { |path| importmap.draw(path) }
+        importmap.draw(path)
+        app.importmaps[namespace] = importmap
+      end
     end
 
     initializer "importmap.reloader" do |app|
@@ -33,10 +44,17 @@ class Engine < ::Rails::Engine
       if app.config.importmap.sweep_cache && !app.config.cache_classes
         app.config.importmap.cache_sweepers << app.root.join("app/javascript")
         app.config.importmap.cache_sweepers << app.root.join("vendor/javascript")
-        app.importmap.cache_sweeper(watches: app.config.importmap.cache_sweepers)
+
+        app.importmaps.values.each do |importmap|
+          importmap.cache_sweeper(watches: app.config.importmap.cache_sweepers)
+        end
 
         ActiveSupport.on_load(:action_controller_base) do
-          before_action { Rails.application.importmap.cache_sweeper.execute_if_updated }
+          before_action do
+            Rails.application.importmaps.values.each do |importmap|
+              importmap.cache_sweeper.execute_if_updated
+            end
+          end
         end
       end
     end

lib/importmap/packager.rb

@@ -10,10 +10,11 @@ class Importmap::Packager
   singleton_class.attr_accessor :endpoint
   self.endpoint = URI("https://api.jspm.io/generate")
 
+  attr_reader :importmap_path
   attr_reader :vendor_path
 
-  def initialize(importmap_path = "config/importmap.rb", vendor_path: "vendor/javascript")
-    @importmap_path = Pathname.new(importmap_path)
+  def initialize(importmap_name = "application", vendor_path: "vendor/javascript")
+    @importmap_path = Pathname.new(importmap_name == "application" ? "config/importmap.rb" : "config/importmaps/#{importmap_name}.rb")
     @vendor_path    = Pathname.new(vendor_path)
   end
 

lib/importmap/reloader.rb

@@ -5,7 +5,9 @@ class Importmap::Reloader
   delegate :execute_if_updated, :execute, :updated?, to: :updater
 
   def reload!
-    import_map_paths.each { |path| Rails.application.importmap.draw(path) }
+    Rails.application.importmaps.values.each do |importmap|
+      import_map_paths.each { |path| importmap.draw(path) }
+    end
   end
 
   private

test/importmap_tags_helper_test.rb

@@ -50,10 +50,12 @@ def content_security_policy_nonce
   end
 
   test "using a custom importmap" do
-    importmap = Importmap::Map.new
-    importmap.pin "foo", preload: true
-    importmap.pin "bar", preload: false
-    importmap_html = javascript_importmap_tags("foo", importmap: importmap)
+    Rails.application.importmaps["custom"] = Importmap::Map.new.tap do |importmap|
+      importmap.pin "foo", preload: true
+      importmap.pin "bar", preload: false
+    end
+
+    importmap_html = javascript_importmap_tags("foo", "custom")
 
     assert_includes importmap_html, %{<script type="importmap" data-turbo-track="reload">}
     assert_includes importmap_html, %{"foo": "/foo.js"}

test/packager_integration_test.rb

@@ -2,7 +2,10 @@
 require "importmap/packager"
 
 class Importmap::PackagerIntegrationTest < ActiveSupport::TestCase
-  setup { @packager = Importmap::Packager.new(Rails.root.join("config/importmap.rb")) }
+  setup do
+    Dir.chdir(Rails.root)
+    @packager = Importmap::Packager.new
+  end
 
   test "successful import against live service" do
     assert_equal "https://ga.jspm.io/npm:react@17.0.2/index.js", @packager.import("react@17.0.2")["react"]
@@ -26,7 +29,7 @@ class Importmap::PackagerIntegrationTest < ActiveSupport::TestCase
   test "successful downloads from live service" do
     Dir.mktmpdir do |vendor_dir|
       @packager = Importmap::Packager.new \
-        Rails.root.join("config/importmap.rb"),
+        "application",
         vendor_path: Pathname.new(vendor_dir)
 
       package_url = "https://ga.jspm.io/npm:@github/webauthn-json@0.5.7/dist/main/webauthn-json.js"
@@ -40,7 +43,7 @@ class Importmap::PackagerIntegrationTest < ActiveSupport::TestCase
       @packager.download("react", package_url)
       assert File.exist?(vendored_package_file)
       assert_equal "// react@17.0.2 downloaded from #{package_url}", File.readlines(vendored_package_file).first.strip
-      
+
       @packager.remove("react")
       assert_not File.exist?(Pathname.new(vendor_dir).join("react.js"))
     end

test/packager_single_quotes_test.rb

@@ -3,9 +3,11 @@
 
 class Importmap::PackagerSingleQuotesTest < ActiveSupport::TestCase
   setup do
-    @single_quote_config_name = Rails.root.join("config/importmap_with_single_quotes.rb")
+    @single_quote_config_name = Rails.root.join("config/importmaps/single_quotes.rb")
+    FileUtils.mkdir_p @single_quote_config_name.dirname
     File.write(@single_quote_config_name, File.read(Rails.root.join("config/importmap.rb")).tr('"', "'"))
-    @packager = Importmap::Packager.new(@single_quote_config_name)
+    Dir.chdir(Rails.root)
+    @packager = Importmap::Packager.new("single_quotes")
   end
 
   teardown { File.delete(@single_quote_config_name) }

test/packager_test.rb

@@ -3,7 +3,10 @@
 require "minitest/mock"
 
 class Importmap::PackagerTest < ActiveSupport::TestCase
-  setup { @packager = Importmap::Packager.new(Rails.root.join("config/importmap.rb")) }
+  setup do
+    Dir.chdir(Rails.root)
+    @packager = Importmap::Packager.new
+  end
 
   test "successful import with mock" do
     response = Class.new do

test/reloader_test.rb

@@ -13,10 +13,10 @@ class ReloaderTest < ActiveSupport::TestCase
   end
 
   test "redraws importmap when config changes" do
-    Rails.application.importmap = Importmap::Map.new.draw { pin "md5", to: "https://cdn.skypack.dev/md5" }
+    Rails.application.importmaps["application"] = Importmap::Map.new.draw { pin "md5", to: "https://cdn.skypack.dev/md5" }
     assert_not_predicate @reloader, :updated?
 
-    assert_changes -> { Rails.application.importmap.packages.keys }, from: %w[ md5 ], to: %w[ md5 not_there ] do
+    assert_changes -> { Rails.application.importmaps["application"].packages.keys }, from: %w[ md5 ], to: %w[ md5 not_there ] do
       touch_config
       assert @reloader.execute_if_updated
     end