Add function impostman-version

impostman.el

@@ -86,6 +86,15 @@ Authorization: Basic dXNlcm5hbWU6cGFzc3dvcmQ="
 
 ;; utility functions
 
+(defun impostman-version (&optional print-dest)
+  "Return the Impostman version.
+
+PRINT-DEST is the output stream, by default the echo area.
+
+With \\[universal-argument] prefix, output is in the current buffer."
+  (interactive (list (if current-prefix-arg (current-buffer) t)))
+  (princ (format "impostman %s" impostman-version) print-dest))
+
 (defun impostman-format-comment (comment &optional prefix)
   "Format a comment, which can be on multiple lines.
 

tests/impostman-test.el

@@ -41,6 +41,15 @@
     (insert-file-contents filename)
     (buffer-string)))
 
+(ert-deftest impostman-test-version ()
+  "Test Impostman version."
+  (let ((impostman-version-output (impostman-version))
+        (expected-string-version (concat "impostman " impostman-version)))
+    ;; version must include at least 3 digits, separated by dots
+    (should (string-match "^impostman [0-9]+\\.[0-9]+\\.[0-9]+"
+                          impostman-version-output))
+    (should (equal impostman-version-output expected-string-version))))
+
 (ert-deftest impostman-test-format-comment ()
   "Test the format of comment."
   ;; without prefix: default is "# "