Improve error message

src/babashka/main.clj

@@ -551,7 +551,9 @@ Use -- to separate script command line args from bb command line args.
                                         (if (str/ends-with? opt ".jar")
                                           :jar :file) opt
                                         :command-line-args (next options))
-                                 (error (str "File does not exist: " opt) 1)))))))
+                                 (error (str (if (str/starts-with? opt ":")
+                                               "Task does not exist: "
+                                               "File does not exist: ") opt) 1)))))))
                      opts-map))]
         opts))))
 

test/babashka/bb_edn_test.clj

@@ -20,6 +20,12 @@
      (binding [test-utils/*bb-edn-path* (str bb-edn-file#)]
        ~@body)))
 
+(deftest task-cli-test
+  (with-config {}
+    (is (thrown-with-msg?
+         Exception #"Task does not exist: :sum"
+         (bb :sum)))))
+
 (deftest babashka-task-test
   (with-config {:tasks {:sum {:task/type :babashka
                               :task/args ["-e" "(+ 1 2 3)"]}}}