Flip default on preload to false

As soon as you add more pins, preloading needs to be an active process.

Author: David Heinemeier Hansson

README.md

@@ -142,14 +142,14 @@ Just like with a normal pin, you can also update a pin by running the `pin --dow
 
 ## Preloading pinned modules
 
-To avoid the waterfall effect where the browser has to load one file after another before it can get to the deepest nested import, we use [modulepreload links](https://developers.google.com/web/updates/2017/12/modulepreload). Pinned modules are preloaded by default, but you can turn this off with `preload: false`.
+To avoid the waterfall effect where the browser has to load one file after another before it can get to the deepest nested import, importmap-rails supports [modulepreload links](https://developers.google.com/web/updates/2017/12/modulepreload). Pinned modules can be preloaded by appending `preload: true` to the pin.
 
 Example:
 
 ```ruby
 # config/importmap.rb
-pin "@github/hotkey", to: "https://ga.jspm.io/npm:@github/[email protected]/dist/index.js"
-pin "md5", to: "https://cdn.jsdelivr.net/npm/[email protected]/md5.js", preload: false
+pin "@github/hotkey", to: "https://ga.jspm.io/npm:@github/[email protected]/dist/index.js", preload: true
+pin "md5", to: "https://cdn.jsdelivr.net/npm/[email protected]/md5.js"
 
 # app/views/layouts/application.html.erb
 <%= javascript_importmap_tags %> 

lib/importmap/map.rb

@@ -22,12 +22,12 @@ def draw(path = nil, &block)
     self
   end
 
-  def pin(name, to: nil, preload: true)
+  def pin(name, to: nil, preload: false)
     clear_cache
     @packages[name] = MappedFile.new(name: name, path: to || "#{name}.js", preload: preload)
   end
 
-  def pin_all_from(dir, under: nil, to: nil, preload: true)
+  def pin_all_from(dir, under: nil, to: nil, preload: false)
     clear_cache
     @directories[dir] = MappedDir.new(dir: dir, under: under, path: to, preload: preload)
   end

lib/install/config/importmap.rb

@@ -3,4 +3,4 @@
 
 # Use npm packages from a JavaScript CDN by running ./bin/importmap
 
-pin "application"
+pin "application", preload: true

test/dummy/config/importmap.rb

@@ -1,4 +1,4 @@
-pin_all_from "app/assets/javascripts", preload: false
+pin_all_from "app/assets/javascripts"
 
-pin "md5", to: "https://cdn.skypack.dev/md5"
-pin "not_there", to: "nowhere.js", preload: false
+pin "md5", to: "https://cdn.skypack.dev/md5", preload: true
+pin "not_there", to: "nowhere.js"

test/importmap_test.rb

@@ -4,16 +4,16 @@ class ImportmapTest < ActiveSupport::TestCase
   def setup
     @importmap = Importmap::Map.new.tap do |map|
       map.draw do
-        pin "application", preload: false
-        pin "editor", to: "rich_text.js", preload: false
-        pin "not_there", to: "nowhere.js", preload: false
-        pin "md5", to: "https://cdn.skypack.dev/md5"
+        pin "application"
+        pin "editor", to: "rich_text.js"
+        pin "not_there", to: "nowhere.js"
+        pin "md5", to: "https://cdn.skypack.dev/md5", preload: true
 
-        pin_all_from "app/javascript/controllers", under: "controllers"
-        pin_all_from "app/javascript/spina/controllers", under: "controllers/spina"
-        pin_all_from "app/javascript/spina/controllers", under: "controllers/spina", to: "spina/controllers"
-        pin_all_from "app/javascript/helpers", under: "helpers"
-        pin_all_from "lib/assets/javascripts"
+        pin_all_from "app/javascript/controllers", under: "controllers", preload: true
+        pin_all_from "app/javascript/spina/controllers", under: "controllers/spina", preload: true
+        pin_all_from "app/javascript/spina/controllers", under: "controllers/spina", to: "spina/controllers", preload: true
+        pin_all_from "app/javascript/helpers", under: "helpers", preload: true
+        pin_all_from "lib/assets/javascripts", preload: true
       end
     end
   end