From 916858e016d52927bfb6205731f678b9d5bb591e Mon Sep 17 00:00:00 2001
From: Michiel Borkent <michielborkent@gmail.com>
Date: Sun, 16 Aug 2020 20:25:58 +0200
Subject: [PATCH] Add -jar option to run uberjar

---
 src/babashka/impl/classpath.clj | 11 +++++++++--
 src/babashka/main.clj           | 16 +++++++++++++++-
 2 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/src/babashka/impl/classpath.clj b/src/babashka/impl/classpath.clj
index d1cd286b..b3820b46 100644
--- a/src/babashka/impl/classpath.clj
+++ b/src/babashka/impl/classpath.clj
@@ -1,8 +1,9 @@
 (ns babashka.impl.classpath
   {:no-doc true}
-  (:require [clojure.java.io :as io]
+  (:require [babashka.impl.clojure.main :refer [demunge]]
+            [clojure.java.io :as io]
             [clojure.string :as str])
-  (:import [java.util.jar JarFile]))
+  (:import [java.util.jar JarFile Manifest]))
 
 (set! *warn-on-reflection* true)
 
@@ -68,6 +69,12 @@
         resource-paths (mapv #(str base-path %) [".bb" ".clj" ".cljc"])]
     (getResource loader resource-paths opts)))
 
+(defn main-ns [manifest-resource]
+  (some-> (Manifest. (io/input-stream manifest-resource))
+          (.getMainAttributes)
+          (.getValue "Main-Class")
+          (demunge)))
+
 ;;;; Scratch
 
 (comment
diff --git a/src/babashka/main.clj b/src/babashka/main.clj
index ea6b2e16..581257b1 100644
--- a/src/babashka/main.clj
+++ b/src/babashka/main.clj
@@ -148,6 +148,11 @@
                        (recur (next options)
                               (assoc opts-map
                                      :file (first options))))
+                     ("--jar" "-jar")
+                     (let [options (next options)]
+                       (recur (next options)
+                              (assoc opts-map
+                                     :jar (first options))))
                      ("--repl")
                      (let [options (next options)]
                        (recur (next options)
@@ -456,7 +461,8 @@ If neither -e, -f, or --socket-repl are specified, then the first argument that
                     :expressions :stream?
                     :repl :socket-repl :nrepl
                     :verbose? :classpath
-                    :main :uberscript :describe?] :as _opts}
+                    :main :uberscript :describe?
+                    :jar] :as _opts}
             (parse-opts args)
             _ (do ;; set properties
                 (when main (System/setProperty "babashka.main" main))
@@ -480,6 +486,8 @@ If neither -e, -f, or --socket-repl are specified, then the first argument that
                           (System/getenv "BABASHKA_CLASSPATH"))
             _ (when classpath
                 (add-classpath* classpath))
+            _ (when jar
+                (add-classpath* jar))
             load-fn (fn [{:keys [:namespace :reload]}]
                       (when-let [{:keys [:loader]}
                                   @cp-state]
@@ -496,6 +504,12 @@ If neither -e, -f, or --socket-repl are specified, then the first argument that
                 (let [abs-path (.getAbsolutePath (io/file file))]
                   (vars/bindRoot sci/file abs-path)
                   (System/setProperty "babashka.file" abs-path)))
+            main (if (and jar (not main))
+                   (when-let [res (cp/getResource
+                                   (:loader @cp-state)
+                                   ["META-INF/MANIFEST.MF"] {:url? true})]
+                     (cp/main-ns res))
+                   main)
             ;; TODO: pull more of these values to compile time
             opts {:aliases aliases
                   :namespaces (-> namespaces