Parse git remote name to determine Heroku app

Several reports have matched #72, which was affecting the `restore`
command for some users. The cause turned out to be local folder names
not matching the name of the Heroku app. Now that Heroku tracks Git
remotes, we can take advantage of the Git remote to correctly identify
the app name even the local folder name doesn't match.

While this requirement has existed for the entirety of Parity's
existence, it stopped being a problem for most commands once Heroku
introduced remotes. I inadvertently reintroduced this requirement in
ad2c21a when we started automatically
bypassing confirmation arguments for restores to non-production
environments.

Fix #72.

Gemfile

@@ -2,5 +2,6 @@ source 'https://rubygems.org'
 
 gemspec
 
-gem 'rake'
-gem 'rspec'
+gem "git"
+gem "rake"
+gem "rspec"

README.md

@@ -98,8 +98,6 @@ Parity expects:
 * A `production` remote pointing to the production Heroku app.
 * There is a `config/database.yml` file that can be parsed as YAML for
   `['development']['database']`.
-* The Heroku apps are named like `app-staging` and `app-production`
-  where `app` is equal to `basename $PWD`.
 
 Customization
 -------------

lib/parity.rb

@@ -3,6 +3,7 @@
 require "parity/version"
 require "parity/environment"
 require "parity/usage"
+require "git"
 require "open3"
 require "pathname"
 require "uri"

lib/parity/environment.rb

@@ -125,8 +125,12 @@ def raw_redis_url
       )[0].strip
     end
 
+    def git_remote
+      Git.init.remote(environment).url
+    end
+
     def heroku_app_name
-      [basename, environment].join('-')
+      git_remote.split(":").last.split(".").first
     end
 
     def basename

spec/parity/environment_spec.rb

@@ -31,8 +31,26 @@
     expect(Kernel).to have_received(:system).with(heroku_backup)
   end
 
+  it "correctly connects to the right Heroku app when the local folder's name does not match the Heroku app's name" do
+    backup = double("backup", restore: nil)
+    stub_git_remote(base_name: "parity-integration", environment: "staging")
+    allow(Parity::Backup).to receive(:new).and_return(backup)
+
+    Parity::Environment.new("staging", ["restore", "production"]).run
+
+    expect(Parity::Backup).
+      to have_received(:new).
+      with(
+        from: "production",
+        to: "staging",
+        additional_args: "--confirm parity-integration-staging",
+      )
+    expect(backup).to have_received(:restore)
+  end
+
   it "restores backups from production to staging" do
     backup = double("backup", restore: nil)
+    stub_git_remote(environment: "staging")
     allow(Parity::Backup).to receive(:new).and_return(backup)
 
     Parity::Environment.new("staging", ["restore", "production"]).run
@@ -49,6 +67,7 @@
 
   it "restores using restore-from" do
     backup = double("backup", restore: nil)
+    stub_git_remote(environment: "staging")
     allow(Parity::Backup).to receive(:new).and_return(backup)
 
     Parity::Environment.new("staging", ["restore-from", "production"]).run
@@ -65,6 +84,7 @@
 
   it "passes the confirm argument when restoring to a non-prod environment" do
     backup = double("backup", restore: nil)
+    stub_git_remote(environment: "staging")
     allow(Parity::Backup).to receive(:new).and_return(backup)
 
     Parity::Environment.new("staging", ["restore", "production"]).run
@@ -102,6 +122,7 @@
 
   it "does not allow restoring backups into production" do
     backup = double("backup", restore: nil)
+    stub_git_remote
     allow(Parity::Backup).to receive(:new).and_return(backup)
     allow($stdout).to receive(:puts)
 
@@ -323,4 +344,14 @@ def stub_migration_path_check(result)
 
     path_stub
   end
+
+  def stub_git_remote(base_name: "parity", environment: "staging")
+    git_remote = double(
+      "Git::Remote",
+      url: "[email protected]:#{base_name}-#{environment}.git",
+    )
+    git = double("Git")
+    allow(git).to receive(:remote).with("staging").and_return(git_remote)
+    allow(Git).to receive(:init).and_return(git)
+  end
 end