Message formatting: don't call `format` unless formatting args are provided

CHANGELOG.md

@@ -27,6 +27,7 @@ Overall quite happy with the state of Timbre as of this release. No major antici
 ### Fixes
  * [#38] Broken namespace filter (mlb-).
  * [unreported] Messages are now generated _after_ middleware has been applied, allowing better filtering performance and more intuitive behaviour (e.g. changes to args in middleware will now automatically percolate to message content).
+ * [unreported] (logf <level> "hello %s") was throwing due to lack of formatting args.
 
 
 ## v2.6.3 → v2.7.1

src/taoensso/timbre.clj

@@ -296,7 +296,8 @@
                                     (assoc  :message
                                       (when-not (empty? args)
                                         (case msg-type
-                                          :format    (apply format    args)
+                                          :format    (if-not (next args) (str args)
+                                                       (apply format args))
                                           :print-str (apply print-str args)
                                           :nil    nil)))))
                   juxtfn-args (assoc juxtfn-args :timestamp (timestamp-fn instant))