Fix `--version' invocation generally working, but terminating with failure exit code (mentioned in issue #21).

Author: doublep

eldev.el

@@ -843,9 +843,13 @@ Returns COMMAND-LINE with options removed."
                         (when (string= term "--help")
                           (when (and (null command) command-line (assq (intern (car command-line)) eldev--commands))
                             (setf command (intern (car command-line))))
-                          (signal 'eldev-quit (if command (eldev-help (symbol-name command)) (eldev-help))))
+                          (if command
+                              (eldev-help (symbol-name command))
+                            (eldev-help))
+                          (signal 'eldev-quit 0))
                         (when (and (null command) (string= term "--version"))
-                          (signal 'eldev-quit (apply #'eldev-version command-line)))
+                          (apply #'eldev-version command-line)
+                          (signal 'eldev-quit 0))
                         (signal 'eldev-wrong-command-usage `(t "Unknown option `%s'" ,term)))))
                   (if long-option
                       (setf term nil)

test/help.el

@@ -9,6 +9,7 @@
                              stdout))
     (should (= exit-code 0))))
 
+;; While `--help' is not advertised, we silently support it.
 (ert-deftest eldev-help-2 ()
   (eldev--test-run "empty-project" ("--help")
     (should (string-prefix-p (eldev--test-in-project-environment (eldev--test-first-line (eldev--test-capture-output (eldev-help))))

test/version.el

@@ -55,6 +55,17 @@
       (should (string= stdout (format "eldev %s\n" (eldev-message-version (eldev-find-package-descriptor 'eldev)))))
       (should (= exit-code 0)))))
 
+;; https://github.com/doublep/eldev/issues/21#issuecomment-688208274
+;;
+;; While `--version' is not advertised, we silently support it.  It is supposed not only
+;; to work as `version' command, but also exit with success code, which it didn't.
+(ert-deftest eldev-own-version-8 ()
+  (let ((eldev--test-project "empty-project"))
+    (eldev--test-delete-cache)
+    (eldev--test-run nil ("--version")
+      (should (string= stdout (format "eldev %s\n" (eldev-message-version (eldev-find-package-descriptor 'eldev)))))
+      (should (= exit-code 0)))))
+
 (ert-deftest eldev-own-version-missing-dependency-1 ()
   (let ((eldev--test-project "missing-dependency-a"))
     (eldev--test-delete-cache)