Better error messages and API tweaks (#12)

* Added better error messages for missing files.
* Added API to check if the manifest exists.
* Added CONTRIBUTING.md doc

.travis.yml

@@ -10,5 +10,4 @@ cache:
 install:
  - bundle install
 script:
- - bundle exec rubocop
- - bundle exec rake test
+ - bundle exec rake

CHANGELOG.md

@@ -6,6 +6,9 @@ Contributors: please follow the recommendations outlined at [keepachangelog.com]
 ## [Unreleased]
 *Please add entries here for your pull requests.*
 
+### Changed
+* Added better error messages for missing files.
+* Added api to check if the manifest exists
 
 ## [2.0.0] - 2017-05-23
 All in [#9](https://github.com/shakacode/webpacker_lite/pull/9) by [justin808](https://github.com/justin808) with help from [conturbo](https://github.com/conturbo) on the tests.

CONTRIBUTING.md

@@ -0,0 +1,70 @@
+# Tips for Contributors
+
+## Summary
+
+For non-doc fixes:
+
+* Provide changelog entry in the [unreleased section of the CHANGELOG.md](https://github.com/shakacode/react_on_rails/blob/master/CHANGELOG.md#unreleased).
+* Ensure CI passes and that you added a test that passes with the fix and fails without the fix.
+* Optionally, squash all commits down to one with a nice commit message *ONLY* once final review is given. Make sure this single commit is rebased on top of master.
+* Please address all code review comments.
+* Ensure that docs are updated accordingly if a feature is added.
+
+## Commit Messages
+
+From [How to Write a Git Commit Message](http://chris.beams.io/posts/git-commit/)
+
+#### The seven rules of a great git commit message
+> Keep in mind: This has all been said before.
+
+1. Separate subject from body with a blank line
+1. Limit the subject line to 50 characters
+1. Capitalize the subject line
+1. Do not end the subject line with a period
+1. Use the imperative mood in the subject line
+1. Wrap the body at 72 characters
+1. Use the body to explain what and why vs. how
+
+
+## To run:
+
+### Tests
+```
+rake test
+```
+
+### Linting
+
+```
+rake rubocop
+```
+
+or to autofix: 
+
+```
+bundle exec rubocop -a
+```
+
+### All ci
+
+```sh
+rake
+```
+
+# Configuring to test changes with your app
+
+Use the relative path syntax in your gemfile.
+
+```ruby
+gem "webpacker_lite", path: "../../../webpacker_lite"
+```
+
+# Advice for Project Maintainers and Contributors
+
+What do project maintainers do? What sort of work is involved? [sstephenson](https://github.com/sstephenson) wrote in the [turbolinks](https://github.com/turbolinks/turbolinks) repo:
+
+> [Why this is not still fully merged?](https://github.com/turbolinks/turbolinks/pull/124#issuecomment-239826060)
+
+# Releasing
+
+

README.md

@@ -83,7 +83,7 @@ This example config shows how we use different output directories for the webpac
 default: &default
  manifest: manifest.json 
  # Used in your webpack configuration. Must be created in the
- # webpack_public_output_dir folder
+ # webpack_public_output_dir folder.
 
 development:
  <<: *default
@@ -141,13 +141,15 @@ production:
 ## Other Helpers: Getting the asset path
 
 The `asset_pack_path` helper provides the path of any given asset that's been compiled by webpack.
+Note, the real file path is the subdirectory of the public.
 
 For example, if you want to create a `<link rel="prefetch">` or `<img />`
 for an asset used in your pack code you can reference them like this in your view,
 
 ```erb
 <img src="<%= asset_pack_path 'calendar.png' %>" />
 <% # => <img src="/webpack/calendar.png" /> %>
+<% # real file path "public/webpack/calendar.png" /> %>
 ```
 
 ## Webpack Helper

Rakefile

@@ -2,11 +2,26 @@
 require "bundler/gem_tasks"
 require "rake/testtask"
 
+# Executes a string or an array of strings in a shell in the given directory
+def sh_in_dir(dir, shell_commands)
+ shell_commands = [shell_commands] if shell_commands.is_a?(String)
+ shell_commands.each { |shell_command| sh %(cd #{dir} && #{shell_command.strip}) }
+end
+
+def gem_root
+ File.expand_path("../.", __FILE__)
+end
+
 Rake::TestTask.new(:test) do |t|
  t.libs << "test"
  t.libs << "lib"
  t.test_files = FileList["test/**/*_test.rb"]
  t.verbose = true
 end
 
-task default: :test
+desc "Run Rubocop as shell"
+task :rubocop do
+ sh_in_dir(gem_root, "bundle exec rubocop .")
+end
+
+task default: [:test, :rubocop]

lib/webpacker_lite.rb

@@ -1,8 +1,8 @@
 module WebpackerLite
  def self.bootstrap
- WebpackerLite::Env.load
- WebpackerLite::Configuration.load
- WebpackerLite::Manifest.load
+ WebpackerLite::Env.load_instance
+ WebpackerLite::Configuration.load_instance
+ WebpackerLite::Manifest.load_instance
  end
 
  def env

lib/webpacker_lite/configuration.rb

@@ -3,15 +3,16 @@
 require "webpacker_lite/env"
 
 class WebpackerLite::Configuration < WebpackerLite::FileLoader
+ RAILS_WEB_PUBLIC = "public"
+
  class << self
  def manifest_path
  Rails.root.join(webpack_public_output_dir,
  configuration.fetch(:manifest, "manifest.json"))
  end
 
  def webpack_public_output_dir
- Rails.root.join(
- File.join("public", configuration.fetch(:webpack_public_output_dir, "webpack")))
+ Rails.root.join(RAILS_WEB_PUBLIC, configuration.fetch(:webpack_public_output_dir, "webpack"))
  end
 
  def base_path
@@ -37,8 +38,8 @@ def base_url
  end
 
  def configuration
- load if WebpackerLite::Env.development?
- raise WebpackerLite::FileLoader::FileLoaderError.new("WebpackerLite::Configuration.load must be called first") unless instance
+ load_instance if WebpackerLite::Env.development?
+ raise WebpackerLite::FileLoader::FileLoaderError.new("WebpackerLite::Configuration.load_instance must be called first") unless instance
  instance.data
  end
 
@@ -48,7 +49,7 @@ def file_path
  end
 
  private
- def load
+ def load_data
  return super unless File.exist?(@path)
  HashWithIndifferentAccess.new(YAML.load(File.read(@path))[WebpackerLite::Env.current])
  end

lib/webpacker_lite/env.rb

@@ -25,7 +25,7 @@ def file_path
  end
 
  private
- def load
+ def load_data
  environments = File.exist?(@path) ? YAML.load(File.read(@path)).keys : [].freeze
  return ENV["NODE_ENV"] if environments.include?(ENV["NODE_ENV"])
  return Rails.env if environments.include?(Rails.env)

lib/webpacker_lite/file_loader.rb

@@ -7,22 +7,22 @@ class FileLoaderError < StandardError; end
  attr_accessor :data
 
  class << self
- def load(path = file_path)
+ def load_instance(path = file_path)
  self.instance = new(path)
  end
 
  def file_path
- raise "Subclass of WebpackerLite::FileLoader should override this method"
+ raise FileLoaderError.new("Subclass of WebpackerLite::FileLoader should override this method")
  end
  end
 
  private
  def initialize(path)
  @path = path
- @data = load
+ @data = load_data
  end
 
- def load
+ def load_data
  {}.freeze
  end
 end

lib/webpacker_lite/manifest.rb

@@ -11,30 +11,61 @@
 
 class WebpackerLite::Manifest < WebpackerLite::FileLoader
  class << self
- def file_path
- WebpackerLite::Configuration.manifest_path
+ # Helper method to determine if the manifest file exists.
+ def exist?
+ path_object = WebpackerLite::Configuration.manifest_path
+ path_object.exist?
  end
 
- def lookup(name)
- load if WebpackerLite::Env.development? || instance.data.empty?
- raise WebpackerLite::FileLoader::FileLoaderError.new("WebpackerLite::Manifest.load must be called first") unless instance
- instance.data[name.to_s] || missing_file_error(name)
+ def file_path
+ WebpackerLite::Configuration.manifest_path
  end
 
- def missing_file_error(name)
+ def missing_file_from_manifest_error(bundle_name)
  msg = <<-MSG
- WebpackerLite can't find #{name} in your manifest #{file_path}. Possible causes:
- 1. You are hot reloading
- 2. Webpack is not running
+ WebpackerLite can't find #{bundle_name} in your manifest #{file_path}. Possible causes:
+ 1. You are hot reloading.
+ 2. Webpack has not re-run to reflect updates.
  3. You have misconfigured WebpackerLite's config/webpacker_lite.yml file.
  4. Your Webpack configuration is not creating a manifest.
  MSG
  raise(WebpackerLite::FileLoader::NotFoundError.new(msg))
  end
+
+ # Same as lookup, but raises an error.
+ def lookup!(name)
+ lookup(name) || missing_file_from_manifest_error(name)
+ end
+
+ # Find the real file name from the manifest key.
+ def lookup(name)
+ instance.confirm_manifest_exists
+
+ load_instance if WebpackerLite::Env.development? || instance.data.empty?
+ raise WebpackerLite::FileLoader::FileLoaderError.new("WebpackerLite::Manifest.load must be called first") unless instance
+ instance.data[name.to_s]
+ end
+ end
+
+ def confirm_manifest_exists
+ raise missing_manifest_file_error(@path) unless File.exist?(@path)
  end
 
  private
- def load
+
+ def missing_manifest_file_error(path_object)
+ msg = <<-MSG
+
+ WebpackerLite can't find the manifest file: #{path_object}
+ Possible causes:
+ 1. You have not invoked webpack.
+ 2. You have misconfigured WebpackerLite's config/webpacker_lite.yml file.
+ 3. Your Webpack configuration is not creating a manifest.
+ MSG
+ raise(WebpackerLite::FileLoader::NotFoundError.new(msg))
+ end
+
+ def load_data
  return super unless File.exist?(@path)
  JSON.parse(File.read(@path))
  end

test/manifest_test.rb

@@ -11,21 +11,21 @@ def test_lookup_exception
  asset_file = "calendar.js"
  msg = <<-MSG
  WebpackerLite can't find #{asset_file} in your manifest #{manifest_path}. Possible causes:
- 1. You are hot reloading
- 2. Webpack is not running
+ 1. You are hot reloading.
+ 2. Webpack has not re-run to reflect updates.
  3. You have misconfigured WebpackerLite's config/webpacker_lite.yml file.
  4. Your Webpack configuration is not creating a manifest.
  MSG
 
  error = assert_raises WebpackerLite::FileLoader::NotFoundError do
- WebpackerLite::Manifest.lookup(asset_file)
+ WebpackerLite::Manifest.lookup!(asset_file)
  end
 
  assert_equal error.message, msg
  end
 
  def test_lookup_success
  asset_file = "bootstrap.js"
- assert_equal WebpackerLite::Manifest.lookup(asset_file), "bootstrap-300631c4f0e0f9c865bc.js"
+ assert_equal WebpackerLite::Manifest.lookup!(asset_file), "bootstrap-300631c4f0e0f9c865bc.js"
  end
 end