LinuxCommand#verify cleaned up

lib/train/extras/command_wrapper.rb

@@ -56,23 +56,29 @@ def verify
       res = @backend.run_command(run("echo"))
       return nil if res.exit_status == 0
 
-      rawerr = res.stdout + " " + res.stderr
-
-      {
-        "Sorry, try again" => ["Wrong sudo password.", :bad_sudo_password],
-        "sudo: no tty present and no askpass program specified" =>
-          ["Sudo requires a password, please configure it.", :sudo_password_required],
-        "sudo: command not found" =>
-          ["Can't find sudo command. Please either install and "\
-            "configure it on the target or deactivate sudo.", :sudo_command_not_found],
-        "sudo: sorry, you must have a tty to run sudo" =>
-          ["Sudo requires a TTY. Please see the README on how to configure "\
-            "sudo to allow for non-interactive usage.", :sudo_no_tty],
-      }.each do |sudo, human|
-        rawerr = human if rawerr.include? sudo
+      rawerr = "#{res.stdout} #{res.stderr}".strip
+
+      case rawerr
+      when "Sorry, try again"
+        ["Wrong sudo password.", :bad_sudo_password]
+      when "sudo: no tty present and no askpass program specified"
+        ["Sudo requires a password, please configure it.", :sudo_password_required]
+      when "sudo: command not found"
+        ["Can't find sudo command. Please either install and "\
+          "configure it on the target or deactivate sudo.", :sudo_command_not_found]
+      when "sudo: sorry, you must have a tty to run sudo"
+        ["Sudo requires a TTY. Please see the README on how to configure "\
+          "sudo to allow for non-interactive usage.", :sudo_no_tty]
+      else
+        [rawerr, nil]
       end
+    end
+
+    def verify!
+      msg, reason = verify
+      return nil unless msg
 
-      rawerr
+      raise Train::UserError.new("Sudo failed: #{msg}", reason)
     end
 
     # (see CommandWrapperBase::run)
@@ -167,15 +173,11 @@ def self.load(transport, options)
         return nil unless LinuxCommand.active?(options)
 
         res = LinuxCommand.new(transport, options)
-        verification_res = res.verify
-        if verification_res
-          msg, reason = verification_res
-          raise Train::UserError.new("Sudo failed: #{msg}", reason)
-        end
+        res.verify!
+
         res
       elsif transport.platform.windows?
-        res = WindowsCommand.new(transport, options)
-        res
+        WindowsCommand.new(transport, options)
       end
     end
   end

test/unit/extras/command_wrapper_test.rb

@@ -106,6 +106,53 @@
       _(lc.run(cmd)).must_equal "echo #{bcmd} | base64 --decode | /bin/bash --login"
     end
   end
+
+  describe "#verify" do
+    def mock_connect_result(stderr, exit_status)
+      OpenStruct.new(stdout: "", stderr: stderr, exit_status: exit_status)
+    end
+
+    it "returns nil on success" do
+      backend.stubs(:run_command).returns(mock_connect_result(nil, 0))
+      lc = cls.new(backend, { sudo: true })
+      _(lc.verify).must_be_nil
+    end
+
+    it "error message for bad sudo password" do
+      backend.stubs(:run_command).returns(mock_connect_result("Sorry, try again", 1))
+      lc = cls.new(backend, { sudo: true })
+      err = _ { lc.verify! }.must_raise Train::UserError
+      _(err.message).must_match(/Sudo failed: Wrong sudo password./)
+    end
+
+    it "error message for sudo password required" do
+      backend.stubs(:run_command).returns(mock_connect_result("sudo: no tty present and no askpass program specified", 1))
+      lc = cls.new(backend, { sudo: true })
+      err = _ { lc.verify! }.must_raise Train::UserError
+      _(err.message).must_match(/Sudo requires a password, please configure it./)
+    end
+
+    it "error message for sudo: command not found" do
+      backend.stubs(:run_command).returns(mock_connect_result("sudo: command not found", 1))
+      lc = cls.new(backend, { sudo: true })
+      err = _ { lc.verify! }.must_raise Train::UserError
+      _(err.message).must_match(/Can't find sudo command. Please either install and configure it on the target or deactivate sudo./)
+    end
+
+    it "error message for requires tty" do
+      backend.stubs(:run_command).returns(mock_connect_result("sudo: sorry, you must have a tty to run sudo", 1))
+      lc = cls.new(backend, { sudo: true })
+      err = _ { lc.verify! }.must_raise Train::UserError
+      _(err.message).must_match(/Sudo failed: Sudo requires a TTY. Please see the README/)
+    end
+
+    it "error message for other sudo related errors" do
+      backend.stubs(:run_command).returns(mock_connect_result("Other sudo related error", 1))
+      lc = cls.new(backend, { sudo: true })
+      err = _ { lc.verify! }.must_raise Train::UserError
+      _(err.message).must_match(/Other sudo related error/)
+    end
+  end
 end
 
 describe "windows command" do