main

src/babashka/main.clj

@@ -84,7 +84,7 @@
 (def bb-edn
   (atom nil))
 
-(defn print-help [command-line-args]
+(defn print-help [ctx command-line-args]
   (if (empty? command-line-args)
     (do
       (println (str "Babashka v" version))
@@ -141,10 +141,18 @@ Use -- to separate script command line args from bb command line args.
     (let [k (first command-line-args)
           k (keyword (subs k 1))
           task (get-in @bb-edn [:tasks k])
+          main (:main task)
           help-text (:task/help task)]
       (if help-text
         [(println help-text) 0]
-        [(println "No help found for task:" k) 1])
+        (if main
+          (let [main (if (simple-symbol? main)
+                       (symbol (str main) "-main")
+                       main)]
+            (if-let [doc (sci/eval-string* ctx (format "(some-> (requiring-resolve '%s) meta :doc)" main))]
+              [(println doc) 0]
+              [(println "No help found for task:" k) 1]))
+          [(println "No help found for task:" k) 1]))
       ,)) ;; end if
   ,) ;; end defn
 
@@ -550,6 +558,10 @@ Use -- to separate script command line args from bb command line args.
                 (-> (p/process args {:inherit true})
                     p/check
                     :exit)])})
+    :main
+    (let [main-arg (:main task)
+          cmd-line-args (:args task)]
+      (parse-opts (seq (map str (concat ["--main" main-arg] cmd-line-args command-line-args)))))
     (error (str "No such task: " (:task/type task)) 1)))
 
 (def should-load-inits?
@@ -701,7 +713,7 @@ Use -- to separate script command line args from bb command line args.
                 (second
                  (cond version-opt
                        [(print-version) 0]
-                       help (print-help command-line-args)
+                       help (print-help sci-ctx command-line-args)
                        tasks (print-tasks tasks)
                        describe?
                        [(print-describe) 0]
@@ -767,6 +779,12 @@ Use -- to separate script command line args from bb command line args.
         exit-code))))
 
 (defn main [& args]
+  (let [bb-edn-file (or (System/getenv "BABASHKA_EDN")
+                        "bb.edn")]
+    (when (fs/exists? bb-edn-file)
+      (let [edn (edn/read-string (slurp bb-edn-file))]
+        (reset! bb-edn edn)
+        (deps/add-deps edn))))
   (let [opts (parse-opts args)]
     (if-let [do-opts (:do opts)]
       (reduce (fn [prev-exit opts]
@@ -788,12 +806,6 @@ Use -- to separate script command line args from bb command line args.
   [& args]
   (handle-pipe!)
   (handle-sigint!)
-  (let [bb-edn-file (or (System/getenv "BABASHKA_EDN")
-                        "bb.edn")]
-    (when (fs/exists? bb-edn-file)
-      (let [edn (edn/read-string (slurp bb-edn-file))]
-        (reset! bb-edn edn)
-        (deps/add-deps edn))))
   (if-let [dev-opts (System/getenv "BABASHKA_DEV")]
     (let [{:keys [:n]} (if (= "true" dev-opts) {:n 1}
                            (edn/read-string dev-opts))

test/babashka/bb_edn_test.clj

@@ -4,8 +4,8 @@
    [babashka.fs :as fs]
    [babashka.test-utils :as test-utils]
    [clojure.edn :as edn]
-   [clojure.test :as test :refer [deftest is testing]]
+   [clojure.string :as str]
-   [clojure.string :as str]))
+   [clojure.test :as test :refer [deftest is testing]]))
 
 (defn bb [& args]
   (edn/read-string
@@ -90,7 +90,7 @@
                                 :args [:do :div-by-zero :or-do :sum]}}}
       (is (= 6 (bb :all))))))
 
-(deftest priotize-user-task-test
+(deftest prioritize-user-task-test
   (is (map? (bb :describe)))
   (with-config {:tasks {:describe {:task/type :babashka
                                    :args ["-e" "(+ 1 2 3)"]}}}
@@ -125,3 +125,13 @@ Addition is a pretty advanced topic.  Let us start with the identity element
       (is (str/includes? res "The following tasks are available:"))
       (is (str/includes? res ":cool-task-1"))
       (is (str/includes? res ":cool-task-2")))))
+
+(deftest main-task-test
+  (with-config {:paths ["test-resources/task_scripts"]
+                :tasks {:main-task {:task/type :main
+                                    :main 'tasks ;; this calls tasks/-main
+                                    :args [1 2 3]}}}
+    (is (= '("1" "2" "3") (bb :main-task)))
+    (let [res (apply test-utils/bb nil
+                     (map str [:help :main-task]))]
+      (is (str/includes? res "Usage: just pass some args")))))

test/babashka/test_utils.clj

@@ -39,9 +39,11 @@
             ;; (prn :err (str es))
             (if (zero? res)
               (str os)
+              (do
+                (println (str os))
                 (throw (ex-info (str es)
                                   {:stdout (str os)
-                               :stderr (str es)})))))
+                                   :stderr (str es)}))))))
       (finally
         (when (string? input-or-opts) (vars/bindRoot sci/in *in*))
         (vars/bindRoot sci/out *out*)