Download all the files associated with a package from a CDN

Gemfile.lock

@@ -104,13 +104,13 @@ GEM
     mini_mime (1.1.2)
     minitest (5.16.2)
     nio4r (2.5.8)
-    nokogiri (1.14.0-aarch64-linux)
+    nokogiri (1.16.0-aarch64-linux)
       racc (~> 1.4)
-    nokogiri (1.14.0-arm64-darwin)
+    nokogiri (1.16.0-arm64-darwin)
       racc (~> 1.4)
-    nokogiri (1.14.0-x86_64-darwin)
+    nokogiri (1.16.0-x86_64-darwin)
       racc (~> 1.4)
-    nokogiri (1.14.0-x86_64-linux)
+    nokogiri (1.16.0-x86_64-linux)
       racc (~> 1.4)
     public_suffix (4.0.7)
     racc (1.6.2)

lib/importmap/commands.rb

@@ -14,16 +14,9 @@ def self.exit_on_failure?
   option :from, type: :string, aliases: :f, default: "jspm"
   def pin(*packages)
     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})
-        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)
-        else
-          append_to_file("config/importmap.rb", "#{pin}\n", verbose: false)
-        end
+      imports.each do |package|
+        puts %(Pinning "#{package.package_name}" to #{packager.vendor_path}/#{package.vendored_package_folder} via download from #{package.base_url})
+        package.download
       end
     else
       puts "Couldn't find any packages in #{packages.inspect} on #{options[:from]}"
@@ -35,10 +28,10 @@ def pin(*packages)
   option :from, type: :string, aliases: :f, default: "jspm"
   def unpin(*packages)
     if imports = packager.import(*packages, env: options[:env], from: options[:from])
-      imports.each do |package, url|
-        if packager.packaged?(package)
-          puts %(Unpinning and removing "#{package}")
-          packager.remove(package)
+      imports.each do |package|
+        if packager.packaged?(package.package_name)
+          puts %(Unpinning and removing "#{package.package_name}")
+          package.remove
         end
       end
     else

lib/importmap/jspm_api.rb

@@ -0,0 +1,91 @@
+class Importmap::JspmApi
+  Error        = Class.new(StandardError)
+  HTTPError    = Class.new(Error)
+  ServiceError = Error.new(Error)
+
+  singleton_class.attr_accessor :generate_endpoint, :download_endpoint
+  self.generate_endpoint = "https://api.jspm.io/generate"
+  self.download_endpoint = "https://api.jspm.io/download"
+
+  def generate(install:, flatten_scope:, env:, provider:)
+    response = post_json(self.class.generate_endpoint, {
+      install:,
+      flattenScope: flatten_scope,
+      env:,
+      provider: normalize_provider(provider)
+    })
+
+    response_json(response)
+  end
+
+  def download(versioned_package_names:, provider:, exclude:)
+    response = post_json("#{self.class.download_endpoint}", {
+      packages: versioned_package_names,
+      provider: normalize_provider(provider),
+      exclude:
+    })
+
+    json = response_json(response)
+
+    return {} if json.blank?
+
+    json.transform_values do |package_download_details|
+      files = package_download_details["files"]
+      package_uri = URI(package_download_details["pkgUrl"])
+
+      Net::HTTP.start(package_uri.hostname, { use_ssl: true }) do |http|
+        files.map do |file|
+          [
+            file,
+            fetch_file(http, "#{package_uri.path}/#{file}")
+          ]
+        end.to_h
+      end
+    end
+  end
+
+  private
+    def fetch_file(http, path)
+      response = http.get(path)
+
+      if response.code == "200"
+        response.body
+      else
+        handle_failure_response(response)
+      end
+    rescue => error
+      raise HTTPError, "Unexpected transport error (#{error.class}: #{error.message})"
+    end
+
+    def response_json(response)
+      case response.code
+      when "200"        then JSON.parse(response.body)
+      when "404", "401" then {}
+      else                   handle_failure_response(response)
+      end
+    end
+
+    def normalize_provider(name)
+      name.to_s == "jspm" ? "jspm.io" : name.to_s
+    end
+
+    def post_json(endpoint, body)
+      Net::HTTP.post(URI(endpoint), body.to_json, "Content-Type" => "application/json")
+    rescue => error
+      raise HTTPError, "Unexpected transport error (#{error.class}: #{error.message})"
+    end
+
+    def handle_failure_response(response)
+      if error_message = parse_service_error(response)
+        raise ServiceError, error_message
+      else
+        raise HTTPError, "Unexpected response code (#{response.code})"
+      end
+    end
+
+    def parse_service_error(response)
+      JSON.parse(response.body.to_s)["error"]
+    rescue JSON::ParserError
+      nil
+    end
+end

lib/importmap/package.rb

@@ -0,0 +1,116 @@
+require "importmap/jspm_api"
+
+class Importmap::Package
+  attr_reader :base_url, :main_url, :package_name
+
+  def initialize(
+    package_name:,
+    main_url:,
+    packager:,
+    provider:
+  )
+    @package_name = package_name
+    @main_url = main_url
+    @packager = packager
+    @provider = provider
+
+    @base_url = extract_base_url_from(main_url)
+    @version = extract_package_version_from(@main_url)
+
+    @main_file = main_url[(base_url.size + 1)..]
+  end
+
+  def download
+    @packager.ensure_vendor_directory_exists
+    remove_existing_package_files
+
+    jspm_api = Importmap::JspmApi.new
+
+    versioned_package_name = "#{@package_name}#{@version}"
+
+    files = jspm_api.download(
+      versioned_package_names: [versioned_package_name],
+      provider: @provider,
+      exclude: ["unused", "readme", "types"]
+    )[versioned_package_name]
+
+    files.each do |file, downloaded_file|
+      save_vendored_file(file, downloaded_file)
+    end
+
+    @packager.pin_package_in_importmap(@package_name, vendored_pin)
+  end
+
+  def remove
+    remove_existing_package_files
+    @packager.remove_package_from_importmap(@package_name)
+  end
+
+  def vendored_package_folder
+    @packager.vendor_path.join(folder_name)
+  end
+
+  private
+    def vendored_pin
+      filename = "#{folder_name}/#{@main_file}"
+
+      %(pin "#{package_name}", to: "#{filename}" # #{@version})
+    end
+
+    def save_vendored_file(file, source)
+      file_name = vendored_package_path_for_file(file)
+      ensure_parent_directories_exist_for(file_name)
+
+      File.open(file_name, "w+") do |vendored_file|
+        vendored_file.write "// #{@package_name}#{@version}/#{file} downloaded from #{base_url}/#{file}\n\n"
+
+        vendored_file.write remove_sourcemap_comment_from(source).force_encoding("UTF-8")
+      end
+    end
+
+    def ensure_parent_directories_exist_for(file)
+      dir_name = File.dirname(file)
+
+      unless File.directory?(dir_name)
+        FileUtils.mkdir_p(dir_name)
+      end
+    end
+
+    def remove_sourcemap_comment_from(source)
+      source.gsub(/^\/\/# sourceMappingURL=.*/, "")
+    end
+
+    def vendored_package_path_for_file(file)
+      vendored_package_folder.join(file)
+    end
+
+    def handle_failure_response(response)
+      if error_message = parse_service_error(response)
+        raise ServiceError, error_message
+      else
+        raise HTTPError, "Unexpected response code (#{response.code})"
+      end
+    end
+
+    def parse_service_error(response)
+      JSON.parse(response.body.to_s)["error"]
+    rescue JSON::ParserError
+      nil
+    end
+
+    def remove_existing_package_files
+      FileUtils.rm_rf vendored_package_folder
+    end
+
+    def folder_name
+      @package_name.gsub("/", "--")
+    end
+
+    def extract_base_url_from(url)
+      url.match(/^.+@\d+\.\d+\.\d+/)&.to_a&.first
+    end
+
+    def extract_package_version_from(url)
+      url.match(/@\d+\.\d+\.\d+/)&.to_a&.first
+    end
+end