Use rollup so we don't need to rely on sprockets

.gitignore

@@ -4,6 +4,7 @@
 .config
 .yardoc
 Gemfile.lock
+package-lock.json
 InstalledFiles
 _yardoc
 coverage
@@ -17,4 +18,5 @@ test/version_tmp
 tmp
 jetty
 spec/internal
-.internal_test_app
+.internal_test_app
+node_modules

README.md

@@ -26,8 +26,8 @@ Run the gallery generator for Sprockets:
 Or for node based bundlers add `blacklight-gallery masonry-layout@v4` as a dependencies and add this to your entrypoint:
 ```js
 import 'blacklight-gallery/vendor/assets/javascripts/imagesloaded.pkgd.js'
-import 'blacklight-gallery/app/assets/javascripts/blacklight_gallery/slideshow'
-import 'blacklight-gallery/app/assets/javascripts/blacklight_gallery/masonry'
+import 'blacklight-gallery/app/javascript/blacklight-gallery/slideshow'
+import 'blacklight-gallery/app/javascript/blacklight-gallery/masonry'
 ```
 
 ## Available Views

app/javascript/blacklight-gallery/index.js

@@ -0,0 +1,5 @@
+import 'imagesloaded.min'
+import 'masonry.min'
+
+import 'blacklight-gallery/slideshow'
+import 'blacklight-gallery/masonry'

config/importmap.rb

@@ -1,4 +1,4 @@
 # frozen_string_literal: true
 
-pin_all_from File.expand_path('../app/assets/javascripts/blacklight_gallery', __dir__), under: 'blacklight_gallery'
+pin_all_from File.expand_path('../app/javascripts/blacklight-gallery', __dir__), under: 'blacklight-gallery'
 pin_all_from File.expand_path('../vendor/assets/javascripts', __dir__)

lib/blacklight/gallery/engine.rb

@@ -4,6 +4,7 @@ module Blacklight
   module Gallery
     class Engine < Rails::Engine
       initializer 'blacklight_gallery.importmap', before: 'importmap' do |app|
+        app.config.assets.paths << Engine.root.join("app/javascript")
         app.config.importmap.paths << Engine.root.join('config/importmap.rb') if app.config.respond_to?(:importmap)
       end
     end

lib/generators/blacklight_gallery/install_generator.rb

@@ -23,7 +23,7 @@ def add_model_mixin
     end
 
     def add_openseadragon
-      gem "openseadragon", ">= 0.2.0"
+      gem "openseadragon", "~> 1.0"
       Bundler.with_clean_env { run 'bundle install' }
       generate 'openseadragon:install'
     end
@@ -34,10 +34,9 @@ def assets
       return unless defined?(Sprockets)
 
       append_to_file 'app/assets/config/manifest.js', "\n//= link blacklight_gallery/manifest.js\n"
-      copy_file "blacklight_gallery.js", "app/assets/javascripts/blacklight_gallery.js"
 
       insert_into_file "app/assets/javascripts/application.js", after: '//= require blacklight/blacklight' do
-        "\n//= require blacklight_gallery"
+        "\n//= require blacklight-gallery/blacklight-gallery"
       end
     end
   end

package.json

@@ -2,9 +2,18 @@
   "name": "blacklight-gallery",
   "version": "4.6.4",
   "description": "Gallery views for Blacklight search results",
-  "main": "app/assets/javascripts/blacklight_gallery/default.js",
+  "exports": {
+    ".": "./app/javascript/blacklight-gallery/index.js",
+    "./*": "./app/javascript/blacklight-gallery/*.js"
+  },
+  "main": "app/assets/javascripts/blacklight_gallery/blacklight-gallery.esm.js",
+  "type": "module",
+  "scripts": {
+    "prepare": "rollup --config rollup.config.js --sourcemap && ESM=true rollup --config rollup.config.js --sourcemap"
+  },
   "files": [
     "app/assets/javascripts/blacklight_gallery/*.js",
+    "app/javascript/blacklight-gallery/*.js",
     "vendor/assets/javascripts/*.js",
     "app/assets/stylesheets/blacklight_gallery/*.scss"
   ],
@@ -18,9 +27,13 @@
     "url": "https://github.com/projectblacklight/blacklight-gallery/issues"
   },
   "homepage": "https://github.com/projectblacklight/blacklight-gallery#readme",
-  "devDependencies": { },
+  "devDependencies": {
+    "rollup": "^4.24.0",
+    "rollup-plugin-includepaths": "^0.2.4"
+  },
   "dependencies": {
     "blacklight-frontend": ">=7.1.0 <9",
+    "openseadragon-rails": "^1.0.10",
     "jquery": ">=3.0"
   }
 }

rollup.config.js

@@ -0,0 +1,31 @@
+import includePaths from 'rollup-plugin-includepaths';
+
+
+const BUNDLE = process.env.BUNDLE === 'true'
+const ESM = process.env.ESM === 'true'
+
+const fileDest = `blacklight-gallery${ESM ? '.esm' : ''}`
+const external = []
+const globals = {}
+
+let includePathOptions = {
+  include: {},
+  paths: ['app/javascript', 'vendor/assets/javascripts'],
+  external: [],
+  extensions: ['.js']
+};
+
+const rollupConfig = {
+  input: 'app/javascript/blacklight-gallery/index.js',
+  output: {
+    file: `app/assets/javascripts/blacklight_gallery/${fileDest}.js`,
+    format: ESM ? 'es' : 'umd',
+    globals,
+    generatedCode: { preset: 'es2015' },
+    name: ESM ? undefined : 'BlacklightGallery'
+  },
+  external,
+  plugins: [includePaths(includePathOptions)]
+}
+
+export default rollupConfig