2 files changed, 34 insertions, 1 deletions
diff --git a/lisp/emacs-lisp/float-sup.el b/lisp/emacs-lisp/float-sup.el
index 50b157b16a4..d92ca5b9337 100644
--- a/lisp/emacs-lisp/float-sup.el
+++ b/lisp/emacs-lisp/float-sup.el
@@ -1,4 +1,4 @@
-;;; float-sup.el --- define some constants useful for floating point numbers.
+;;; float-sup.el --- define some constants useful for floating point numbers.  -*- lexical-binding:t -*-
 
 ;; Copyright (C) 1985-1987, 2001-2020 Free Software Foundation, Inc.
 
diff --git a/test/lisp/emacs-lisp/float-sup-tests.el b/test/lisp/emacs-lisp/float-sup-tests.el
new file mode 100644
index 00000000000..9f9a3daa28b
--- /dev/null
+++ b/test/lisp/emacs-lisp/float-sup-tests.el
@@ -0,0 +1,33 @@
+;;; float-sup-tests.el --- Tests for float-sup.el  -*- lexical-binding:t -*-
+
+;; Copyright (C) 2020 Free Software Foundation, Inc.
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;;; Code:
+
+(require 'ert)
+
+(ert-deftest float-sup-degrees-and-radians ()
+  (should (equal (degrees-to-radians 180.0) float-pi))
+  (should (equal (radians-to-degrees float-pi) 180.0))
+  (should (equal (radians-to-degrees (degrees-to-radians 360.0)) 360.0))
+  (should (equal (degrees-to-radians (radians-to-degrees float-pi)) float-pi)))
+
+(provide 'float-sup-tests)
+;;; float-sup-tests.el ends here