ruby-method-params-indent: New user option

* lisp/progmodes/ruby-mode.el (ruby-method-params-indent):
New option (bug#60110).

(ruby-smie-rules): Use it.

* etc/NEWS: Mention it.

* test/lisp/progmodes/ruby-mode-resources/ruby.rb:
Ensure the var's value is default.

* test/lisp/progmodes/ruby-mode-resources/ruby-method-params-indent.rb:
New file.

* test/lisp/progmodes/ruby-mode-tests.el (ruby-deftest-indent):
New macro, use it to run the indentation test using the new file.
Disable the :expensive-test tag, because neither runs for "longer
than some few seconds", both take significantly below 1s.

1 files changed, 23 insertions, 3 deletions

diff --git a/lisp/progmodes/ruby-mode.el b/lisp/progmodes/ruby-mode.el
index d7efe982870..2b813dfcbcc 100644
--- a/lisp/progmodes/ruby-mode.el
+++ b/lisp/progmodes/ruby-mode.el
@@ -268,6 +268,23 @@ Only has effect when `ruby-use-smie' is t."
   :safe 'booleanp
   :version "24.4")
 
+(defcustom ruby-method-params-indent t
+  "Indentation  of multiline method parameters.
+
+When t, the parameters list is indented to the method name.
+
+When a number, indent the parameters list this many columns
+against the beginning of the method (the \"def\" keyword).
+
+The value nil means the same as 0.
+
+Only has effect when `ruby-use-smie' is t."
+  :type '(choice (const :tag "Indent to the method name" t)
+                 (number :tag "Indent specified number of columns against def")
+                 (const :tag "Indent to def" nil))
+  :safe (lambda (val) (or (memq val '(t nil)) (numberp val)))
+  :version 29.1)
+
 (defcustom ruby-deep-arglist t
   "Deep indent lists in parenthesis when non-nil.
 Also ignores spaces after parenthesis when `space'.
@@ -660,9 +677,12 @@ This only affects the output of the command `ruby-toggle-block'."
        (unless (or (eolp) (forward-comment 1))
          (cons 'column (current-column)))))
     ('(:before . " @ ")
-     (save-excursion
-       (skip-chars-forward " \t")
-       (cons 'column (current-column))))
+     (if (or (eq ruby-method-params-indent t)
+             (not (smie-rule-parent-p "def" "def=")))
+         (save-excursion
+           (skip-chars-forward " \t")
+           (cons 'column (current-column)))
+       (smie-rule-parent (or ruby-method-params-indent 0))))
     ('(:before . "do") (ruby-smie--indent-to-stmt))
     ('(:before . ".")
      (if (smie-rule-sibling-p)