Use the heroku gem's --remote option. Close issue #21.

README.md

@@ -100,7 +100,7 @@ Yes. To indicate that a particular app is using Cedar, run with the -c flag:
       a465afd..bc8932b  master -> master
     ==> - true
     ==> Pushed master -> heroku-staging
-    ==> + bundle exec heroku rake db:migrate --app staging-sushi
+    ==> + bundle exec heroku rake db:migrate --remote staging-sushi
     ... Postgres output removed ...
     ==> - false
     ==> Migrated staging-sushi

features/kumade_executable.feature

@@ -27,7 +27,7 @@ Feature: Kumade executable
                run  git branch deploy
                run  git push -f pretend-staging deploy:master
       ==> Pushed deploy:master -> pretend-staging
-      ==> Migrated pretend-staging-app
+      ==> Migrated pretend-staging
                run  git checkout master && git branch -D deploy
       ==> Deployed to: pretend-staging
       """
@@ -58,7 +58,7 @@ Feature: Kumade executable
                run  git branch deploy
                run  git push -f pretend-staging deploy:master
       ==> Pushed deploy:master -> pretend-staging
-      ==> Migrated pretend-staging-app
+      ==> Migrated pretend-staging
                run  git checkout new_branch && git branch -D deploy
       ==> Deployed to: pretend-staging
       """

lib/kumade/deployer.rb

@@ -36,23 +36,21 @@ def sync_heroku
     end
 
     def heroku_migrate
-      app = Kumade::Git.app_for(environment)
-
-      heroku("rake db:migrate", app) unless pretending
-      success("Migrated #{app}")
+      heroku("rake db:migrate") unless pretending
+      success("Migrated #{environment}")
     end
 
     def post_deploy
       git.delete(DEPLOY_BRANCH, @branch)
     end
 
-    def heroku(command, app)
+    def heroku(command)
       heroku_command = if @cedar
                          "bundle exec heroku run"
                        else
                          "bundle exec heroku"
                        end
-      run_or_error("#{heroku_command} #{command} --app #{app}",
+      run_or_error("#{heroku_command} #{command} --remote #{environment}",
                    "Failed to run #{command} on Heroku")
     end
 
@@ -146,7 +144,7 @@ def custom_task?
 
     def ensure_heroku_remote_exists
       if git.remote_exists?(environment)
-        if app_name = Kumade::Git.app_for(environment)
+        if git.heroku_remote?
           success("#{environment} is a Heroku remote")
         else
           error(%{Cannot deploy: "#{environment}" remote does not point to Heroku})

lib/kumade/git.rb

@@ -1,18 +1,14 @@
 module Kumade
   class Git < Base
+    attr_reader :environment
     def initialize(pretending, environment)
       super()
       @pretending = pretending
       @environment = environment
     end
 
-    def self.app_for(environment)
-      heroku_git_url = `git config --get remote.#{environment}.url`.strip
-      if heroku_git_url =~ /^git@heroku\.com:(.+)\.git$/
-        $1
-      else
-        nil
-      end
+    def heroku_remote?
+      `git config --get remote.#{environment}.url`.strip =~ /^git@heroku\.com:(.+)\.git$/
     end
 
     def self.environments

spec/kumade/deployer_spec.rb

@@ -30,11 +30,10 @@
 
 describe Kumade::Deployer, "#deploy" do
   let(:remote_name){ 'staging' }
-  let(:app_name){ 'kumade-staging' }
 
   before do
     subject.stub(:say)
-    force_add_heroku_remote(remote_name, app_name)
+    force_add_heroku_remote(remote_name)
   end
 
   it "calls the correct methods in order" do
@@ -361,18 +360,17 @@ class More
 
 describe Kumade::Deployer, "#heroku_migrate" do
   let(:environment){ 'staging' }
-  let(:app_name){ 'sushi' }
 
   before do
     subject.stub(:say)
-    force_add_heroku_remote(environment, app_name)
+    force_add_heroku_remote(environment)
   end
 
   it "runs db:migrate with the correct app" do
     subject.stub(:run => true)
     subject.should_receive(:heroku).
-      with("rake db:migrate", app_name)
-    subject.should_receive(:success).with("Migrated #{app_name}")
+      with("rake db:migrate")
+    subject.should_receive(:success).with("Migrated staging")
 
     subject.heroku_migrate
   end
@@ -381,11 +379,10 @@ class More
 describe Kumade::Deployer, "#ensure_heroku_remote_exists" do
   let(:environment){ 'staging' }
   let(:bad_environment){ 'bad' }
-  let(:staging_app_name) { 'staging-sushi' }
 
   before do
     subject.stub(:say)
-    force_add_heroku_remote(environment, staging_app_name)
+    force_add_heroku_remote(environment)
     `git remote add #{bad_environment} blerg@example.com`
   end
 
@@ -429,23 +426,21 @@ class More
 end
 
 describe Kumade::Deployer, "#heroku" do
-  let(:app_name){ 'sushi' }
-
   context "when on Cedar" do
     subject { Kumade::Deployer.new('staging', false, cedar = true) }
 
     it "runs commands with `run`" do
-      subject.should_receive(:run_or_error).with("bundle exec heroku run rake --app #{app_name}", //)
-      subject.heroku("rake", app_name)
+      subject.should_receive(:run_or_error).with("bundle exec heroku run rake --remote staging", //)
+      subject.heroku("rake")
     end
   end
 
   context "when not on Cedar" do
     subject { Kumade::Deployer.new('staging', false, cedar = false) }
 
     it "runs commands without `run`" do
-      subject.should_receive(:run_or_error).with("bundle exec heroku rake --app #{app_name}", //)
-      subject.heroku("rake", app_name)
+      subject.should_receive(:run_or_error).with("bundle exec heroku rake --remote staging", //)
+      subject.heroku("rake")
     end
   end
 end

spec/kumade/git_spec.rb

@@ -1,41 +1,35 @@
 require 'spec_helper'
 
-describe Kumade::Git, ".app_for" do
+describe Kumade::Git, "#heroku_remote?" do
   let(:environment){ 'staging' }
-  let(:app_name){ 'staging_test' }
   let(:not_a_heroku_env){ 'fake_heroku' }
   let(:not_a_heroku_url){ 'git@github.com:gabebw/kumade.git' }
 
   before do
-    force_add_heroku_remote(environment, app_name)
+    force_add_heroku_remote(environment)
     `git remote add #{not_a_heroku_env} #{not_a_heroku_url}`
   end
   after do
     remove_remote(environment)
     remove_remote(not_a_heroku_env)
   end
-
-  it "autodetects the Heroku app name" do
-    Kumade::Git.app_for(environment).should == app_name
-  end
-
-  it "is nil if the app cannot be found" do
-    Kumade::Git.app_for('xyz').should be_nil
+
+  it "should return true when environment remote is a heroku repository" do
+    Kumade::Git.new(false, environment).heroku_remote?.should be_true
   end
 
-  it "is nil if the remote is not a Heroku remote" do
-    Kumade::Git.app_for(not_a_heroku_env).should be_nil
+  it "should return false when environment remote isn't a heroku repository" do
+    Kumade::Git.new(false, 'kumade').heroku_remote?.should be_false
   end
 end
 
 describe Kumade::Git, ".environments" do
   let(:environment){ 'staging' }
-  let(:app_name){ 'staging_test' }
   let(:not_a_heroku_env){ 'fake_heroku' }
   let(:not_a_heroku_url){ 'git@github.com:gabebw/kumade.git' }
 
   before do
-    force_add_heroku_remote(environment, app_name)
+    force_add_heroku_remote(environment)
     `git remote add #{not_a_heroku_env} #{not_a_heroku_url}`
   end
   after do

spec/spec_helper.rb

@@ -5,9 +5,9 @@
 require 'aruba/api'
 
 module GitRemoteHelpers
-  def force_add_heroku_remote(remote_name, app_name)
+  def force_add_heroku_remote(remote_name)
     remove_remote(remote_name)
-    `git remote add #{remote_name} git@heroku.com:#{app_name}.git`
+    `git remote add #{remote_name} git@heroku.com:#{remote_name}.git`
   end
 
   def remove_remote(remote_name)