Introduce ember-cli-deploy integration

README.md

@@ -200,6 +200,93 @@ watch them for changes as well.
 directories %w[app config lib spec your-appname/app]
 ```
 
+## Integrating with `ember-cli-deploy`
+
+The EmberCLI community recently unified the various deployment techniques into a
+single, core-team supported project: [ember-cli-deploy][ember-cli-deploy].
+
+This project attempts to streamline the process of pushing and serving
+EmberCLI-built static assets.
+
+To integrate with `ember-cli-deploy`'s ["Lightning Fast Deploys"][lightning]
+(using the Redis adapter), instantiate an `EmberCLI::Deploy` in your controller:
+
+```ruby
+require "ember-cli/deploy"
+
+class ApplicationController < ActionController::Base
+  def index
+    @deploy = EmberCLI::Deploy.new(namespace: "frontend")
+
+    render text: @deploy.html, layout: false
+  end
+end
+```
+
+`EmberCLI::Deploy` takes a `namespace` (the name of your app declared in your
+initializer) and handles all interaction with the Redis instance.
+
+This is great for `staging` and `production` deploys, but introduces an extra
+step in the feedback loop during development.
+
+Luckily, `EmberCLI::Deploy` also accepts an `index_html` override, which will
+replace the call to the Redis instance. This allows integration with the normal
+`ember-cli-rails` workflow:
+
+```ruby
+require "ember-cli/deploy"
+
+class ApplicationController < ActionController::Base
+  def index
+    @deploy = EmberCLI::Deploy.new(
+      namespace: "frontend",
+      index_html: index_html,
+    )
+
+    render text: @deploy.html, layout: false
+  end
+
+  private
+
+  def index_html
+    if serve_with_ember_cli_rails?
+      render_to_string(:index)
+    end
+  end
+
+  def serve_with_ember_cli_rails?
+    ! %w[production staging].include?(Rails.env)
+  end
+end
+```
+
+Additionally, having access to the outbound HTML beforehand also enables
+controllers to inject additional markup, such as metadata, CSRF tokens, or
+analytics tags:
+
+
+```ruby
+require "ember-cli/deploy"
+
+class ApplicationController < ActionController::Base
+  def index
+    @deploy = EmberCLI::Deploy.new(
+      namespace: "frontend",
+      index_html: index_html,
+    )
+
+    @deploy.append_to_head(render_to_string(partial: "my_csrf_and_metadata")
+    @deploy.append_to_body(render_to_string(partial: "my_analytics")
+
+    render text: @deploy.html, layout: false
+  end
+  # ...
+end
+```
+
+[ember-cli-deploy]: https://github.com/ember-cli/ember-cli-deploy
+[lightning]: https://github.com/ember-cli/ember-cli-deploy#lightning-approach-workflow
+
 ## Heroku
 
 In order to deploy EmberCLI Rails app to Heroku:

ember-cli-rails.gemspec

@@ -13,5 +13,10 @@ Gem::Specification.new do |spec|
   spec.required_ruby_version = ">= 1.9.3"
 
   spec.add_dependency "railties", ">= 3.1", "< 5"
+  spec.add_dependency "redis"
   spec.add_dependency "sprockets", ">= 2.0"
+
+  spec.add_development_dependency "rspec", "~> 3.1.0"
+  spec.add_development_dependency "climate_control"
+  spec.add_development_dependency "fakeredis"
 end

lib/ember-cli/deploy.rb

@@ -0,0 +1,79 @@
+require "active_support/core_ext/object/blank"
+require "ember-cli/page"
+
+module EmberCLI
+  class Deploy
+    def initialize(namespace:, index_html: nil)
+      @namespace = namespace
+      @index_html = index_html
+      @body_markup = []
+      @head_markup = []
+    end
+
+    def append_to_body(markup)
+      body_markup << markup
+    end
+
+    def append_to_head(markup)
+      head_markup << markup
+    end
+
+    def html
+      if index_html.present?
+        page = Page.new(html: index_html)
+
+        body_markup.each do |markup|
+          page.append_to_body(markup)
+        end
+
+        head_markup.each do |markup|
+          page.append_to_head(markup)
+        end
+
+        page.build
+      else
+        index_html_missing!
+      end
+    end
+
+    private
+
+    attr_reader :body_markup, :head_markup, :namespace
+
+    def index_html
+      @index_html ||= redis.get(deploy_key).presence
+    end
+
+    def current_key
+      "#{namespace}:current"
+    end
+
+    def deploy_key
+      redis.get(current_key).presence || deployment_not_activated!
+    end
+
+    def redis
+      Redis.new(url: ENV.fetch("REDIS_URL"))
+    end
+
+    def index_html_missing!
+      message = <<-FAIL
+        HTML for #{deploy_key} is missing.
+
+        Did you forget to call `ember deploy`?
+      FAIL
+
+      raise KeyError, message
+    end
+
+    def deployment_not_activated!
+      message = <<-FAIL
+        #{current_key} is empty.
+
+        Did you forget to call `ember deploy:activate`?
+      FAIL
+
+      raise KeyError, message
+    end
+  end
+end

lib/ember-cli/page.rb

@@ -0,0 +1,53 @@
+module EmberCLI
+  class Page
+    def initialize(html:)
+      @html = html.clone
+      @body_markup = []
+      @head_markup = []
+    end
+
+    def build
+      if has_head?
+        head_markup.each do |markup|
+          html.insert(head_position, markup)
+        end
+      end
+
+      if has_body?
+        body_markup.each do |markup|
+          html.insert(body_position, markup)
+        end
+      end
+
+      html
+    end
+
+    def append_to_body(markup)
+      body_markup << markup
+    end
+
+    def append_to_head(markup)
+      head_markup << markup
+    end
+
+    private
+
+    attr_reader :body_markup, :head_markup, :html
+
+    def has_head?
+      html.include?("<head")
+    end
+
+    def has_body?
+      html.include?("<body")
+    end
+
+    def head_position
+      html.index(">", html.index("<head")) + 1
+    end
+
+    def body_position
+      html.index(">", html.index("<body")) + 1
+    end
+  end
+end

spec/lib/ember-cli/deploy_spec.rb

@@ -0,0 +1,108 @@
+require "spec_helper"
+require "ember-cli/deploy"
+
+describe EmberCLI::Deploy do
+  describe "#append_to_head" do
+    it "injects the string into the <head> tag" do
+      provided_html = "<html><head></head></html>"
+      ember_cli_deploy = build_ember_cli_deploy(index_html: provided_html)
+
+      ember_cli_deploy.append_to_head("<script></script>")
+      index_html = ember_cli_deploy.html
+
+      expect(index_html).to eq("<html><head><script></script></head></html>")
+    end
+  end
+
+  describe "#append_to_body" do
+    it "injects the string into the <body> tag" do
+      provided_html = "<html><body></body></html>"
+      ember_cli_deploy = build_ember_cli_deploy(index_html: provided_html)
+
+      ember_cli_deploy.append_to_body("<script></script>")
+      index_html = ember_cli_deploy.html
+
+      expect(index_html).to eq("<html><body><script></script></body></html>")
+    end
+  end
+
+  describe "#html" do
+    context "when the HTML is provided" do
+      it "returns the HTML" do
+        provided_html = "<p>Hello World</p>"
+        ember_cli_deploy = build_ember_cli_deploy(index_html: provided_html)
+
+        index_html = ember_cli_deploy.html
+
+        expect(index_html).to eq(provided_html)
+      end
+    end
+
+    context "when the keys are present" do
+      it "retrieves the HTML from Redis" do
+        stub_index_html(html: "<p>Hello World</p>")
+        ember_cli_deploy = build_ember_cli_deploy
+
+        index_html = ember_cli_deploy.html
+
+        expect(index_html).to eq("<p>Hello World</p>")
+      end
+    end
+
+    context "when the current index is missing" do
+      it "raises a helpful exception" do
+        deploy_key = "#{namespace}:abc123"
+        stub_index_html(html: nil, deploy_key: deploy_key)
+        ember_cli_deploy = build_ember_cli_deploy
+
+        expect { ember_cli_deploy.html }.to raise_error(
+          /HTML for #{deploy_key} is missing/
+        )
+      end
+    end
+
+    context "when the current key is unset" do
+      it "raises a helpful exception" do
+        stub_current_key(nil)
+        ember_cli_deploy = build_ember_cli_deploy
+
+        expect { ember_cli_deploy.html }.to raise_error(
+          /#{namespace}:current is empty/
+        )
+      end
+    end
+  end
+
+  around :each do |example|
+    with_modified_env REDIS_URL: "redis://localhost:1234" do
+      example.run
+    end
+  end
+
+  def build_ember_cli_deploy(index_html: nil)
+    EmberCLI::Deploy.new(namespace: namespace, index_html: index_html)
+  end
+
+  def namespace
+    "human-health"
+  end
+
+  def stub_current_key(deploy_key)
+    current_key = "#{namespace}:current"
+
+    redis.set(current_key, deploy_key)
+  end
+
+  def stub_index_html(deploy_key: "#{namespace}:123", html:)
+    stub_current_key(deploy_key)
+    redis.set(deploy_key, html)
+  end
+
+  def redis
+    Redis.new(url: ENV["REDIS_URL"])
+  end
+
+  def with_modified_env(options, &block)
+    ClimateControl.modify(options, &block)
+  end
+end

spec/spec_helper.rb

@@ -0,0 +1,2 @@
+require "fakeredis"
+require "climate_control"