teach `hub apply` about GitHub URLs, same as `hub am`

lib/hub/commands.rb

@@ -254,6 +254,11 @@ module Hub
       end
     end
 
+    # $ hub apply https://github.com/defunkt/hub/pull/55
+    # > curl https://github.com/defunkt/hub/pull/55.patch -o /tmp/55.patch
+    # > git apply /tmp/55.patch
+    alias_method :apply, :am
+
     # $ hub init -g
     # > git init
     # > git remote add origin git@github.com:USER/REPO.git

test/hub_test.rb

@@ -387,6 +387,41 @@ class HubTest < Test::Unit::TestCase
     end
   end
 
+  def test_apply_untouched
+    assert_forwarded "apply some.patch"
+  end
+
+  def test_apply_pull_request
+    with_tmpdir('/tmp/') do
+      assert_commands "curl -#LA 'hub #{Hub::Version}' https://github.com/defunkt/hub/pull/55.patch -o /tmp/55.patch",
+                      "git apply /tmp/55.patch -p2",
+                      "apply https://github.com/defunkt/hub/pull/55 -p2"
+
+      cmd = Hub("apply https://github.com/defunkt/hub/pull/55/files").command
+      assert_includes '/pull/55.patch', cmd
+    end
+  end
+
+  def test_apply_commit_url
+    with_tmpdir('/tmp/') do
+      url = 'https://github.com/davidbalbert/hub/commit/fdb9921'
+
+      assert_commands "curl -#LA 'hub #{Hub::Version}' #{url}.patch -o /tmp/fdb9921.patch",
+                      "git apply /tmp/fdb9921.patch -p2",
+                      "apply #{url} -p2"
+    end
+  end
+
+  def test_apply_gist
+    with_tmpdir('/tmp/') do
+      url = 'https://gist.github.com/8da7fb575debd88c54cf'
+
+      assert_commands "curl -#LA 'hub #{Hub::Version}' #{url}.txt -o /tmp/gist-8da7fb575debd88c54cf.txt",
+                      "git apply /tmp/gist-8da7fb575debd88c54cf.txt -p2",
+                      "apply #{url} -p2"
+    end
+  end
+
   def test_init
     assert_commands "git init", "git remote add origin git@github.com:tpw/hub.git", "init -g"
   end