Introduce Pusher::Client.from_env

This allows to have a counterpart to the Pusher singleton when using an
environment variable for config.

Author: zimbatm

README.md

@@ -55,6 +55,13 @@ pusher_client = Pusher::Client.new(
 
 This will set the `host` to `api-<cluster>.pusher.com`. If you pass both `host` and `cluster` options, the `host` will take precendence and `cluster` will be ignored.
 
+Finally, if you have the configuration set in an `PUSHER_URL` environment
+variable, you can use:
+
+``` ruby
+pusher_client = Pusher::Client.from_env
+```
+
 ### Global
 
 Configuring Pusher can also be done globally on the Pusher class.

lib/pusher/client.rb

@@ -9,6 +9,14 @@ class Client
 
     ## CONFIGURATION ##
 
+    # Loads the configuration from an url in the environment
+    def self.from_env(key = 'PUSHER_URL')
+      url = ENV[key] || raise(ConfigurationError, key)
+      client = new
+      client.url = url
+      client
+    end
+
     def initialize(options = {})
       default_options = {
         :scheme => 'http',

spec/client_spec.rb

@@ -65,6 +65,7 @@
           @client.url
         }.to raise_error(Pusher::ConfigurationError)
       end
+
     end
 
     describe 'configuring the cluster' do
@@ -107,6 +108,20 @@
       end
     end
 
+    describe 'configuring from env' do
+      it "works" do
+        url = "http://somekey:somesecret@api.staging.pusherapp.com:8080/apps/87"
+        ENV['PUSHER_URL'] = url
+
+        client = Pusher::Client.from_env
+        expect(client.key).to eq("somekey")
+        expect(client.secret).to eq("somesecret")
+        expect(client.app_id).to eq("87")
+        expect(client.url.to_s).to eq("http://api.staging.pusherapp.com:8080/apps/87")
+        ENV['PUSHER_URL'] = nil
+      end
+    end
+
     describe 'when configured' do
       before :each do
         @client.app_id = '20'