[dpaste] Add system tests

plugins/dpaste/tests/test_dpaste.fish

 #!/usr/bin/env fish
+# vim: ai ts=2 sw=2 et sts=2
+
+
+function echo_text
+  set -g __test_text 'Hello, tests! I am just testing suite for oh-my-fish plugin: https://github.com/bpinto/oh-my-fish/pull/170'
+  echo -e $__test_text 
+end
+
+function curl
+  command curl --silent $argv
+end
+
+function curl_and_check
+  assert_equal $argv[2..-1] (curl $argv[1])
+end
+
+function curl_and_fail
+  assert_match '.*404 Not found.*' (curl $argv[1])
+end
+
+function test_dpaste_system
+  set url (eval $argv[1])/raw
+  # everything is correct:
+  # one time snippets are available twice if you use curl
+  curl_and_check $url (echo_text)
+  curl_and_check $url (echo_text)
+  # now it shouldn't be available
+  curl_and_fail $url
+end
+
+function dpaste_setup
+  set -g test_dir /tmp/dpaste_test
+  set -g test_file $test_dir/file
+  mkdir -p $test_dir
+  pushd
+  cd $test_dir
+  echo_text > $test_file
+end
+
+function dpaste_teardown
+  rm -rf $test_dir
+  popd
+end
 
 function suite_dpaste
   function setup
@@ -16,11 +59,44 @@ function suite_dpaste
     assert_equal "https://dpaste.de/api/?format=url&expires=3600" $__dpaste_send_url
     set -g __dpaste_send_url $dpaste_url
   end
+
+  function test_dpaste_system_file_redirect
+    function dpaste_file_redirect
+      dpaste -t onetime < /tmp/dpaste_test/file
+    end
+    test_dpaste_system dpaste_file_redirect
+  end
+
+  function test_dpaste_system_file
+    function dpaste_file
+      dpaste -t onetime /tmp/dpaste_test/file
+    end
+    test_dpaste_system dpaste_file
+  end
+
+  function test_dpaste_system_stdin
+    function dpaste_stdin
+      echo_text | dpaste -t onetime
+    end
+    test_dpaste_system dpaste_stdin
+  end
+
+  function test_dpaste_system_text
+    function dpaste_text
+      dpaste -t onetime "$__test_text"
+    end
+    test_dpaste_system dpaste_text
+  end
 end
 
+
 if not set -q tank_running
   source (dirname (status -f))/helper.fish
   set -g __dpaste_expires_choises
   source (dirname (status -f))/../dpaste.fish
+
+  dpaste_setup
   tank_run
+  dpaste_teardown
 end
+