test case for rust-mode emacs fix

gistfile1.txt

(defun rust-test-fn (code expected-result)
  (with-temp-buffer
    (rust-mode)
    (insert code)
    ;; check window before formatting
    (let (w-start (window-start))
      (message "%s" w-start)
      )
    (rust-format-buffer)
    (should (equal expected-result (buffer-string)))

    ;; check window start after formatting
    (let (w-start (window-start))
      (message "%s" w-start)
      )

    )
  )


;; Running the test
(ert-deftest rust-test-formatting-on-save-buffer ()
  (rust-test-fn
   "struct Foo {}

impl Bar for Foo {
    fn dummy_spacer() -> bool {
        false
    }

    fn dummy_spacer() -> bool {
        false
    }

    fn dummy_spacer() -> bool {
        false
    }

    fn dummy_spacer() -> bool {
        false
    }

    fn dummy_spacer() -> bool {
        false
    }

    fn dummy_spacer() -> bool {
        false
    }

    fn dummy_spacer() -> bool {
        false
    }

    fn dummy_spacer() -> bool {
        false
    }

    fn dummy_spacer() -> bool {
        false
    }

    fn dummy_spacer() -> bool {
        false
    }

    fn dummy_spacer() -> bool {
        false
    }

    fn test_function(
        &self, param1: String,
        param2: String,
        param3: String,
        param4: String,
    ) -> bool {
        false
    }
}
"

   "struct Foo {}

impl Bar for Foo {
    fn dummy_spacer() -> bool {
        false
    }

    fn dummy_spacer() -> bool {
        false
    }

    fn dummy_spacer() -> bool {
        false
    }

    fn dummy_spacer() -> bool {
        false
    }

    fn dummy_spacer() -> bool {
        false
    }

    fn dummy_spacer() -> bool {
        false
    }

    fn dummy_spacer() -> bool {
        false
    }

    fn dummy_spacer() -> bool {
        false
    }

    fn dummy_spacer() -> bool {
        false
    }

    fn dummy_spacer() -> bool {
        false
    }

    fn dummy_spacer() -> bool {
        false
    }

    fn test_function(
        &self,
        param1: String,
        param2: String,
        param3: String,
        param4: String,
    ) -> bool {
        false
    }
}
"
   ))