Handle exit by promisifying lumo compilation

This patch fixes the fact that serverless could not display the failures of
compilation in lumo. It also needs the very latest lumo for it to work.

serverless-cljs-plugin/serverless_lumo/build.cljs

@@ -4,7 +4,7 @@
             [cljs.reader :as reader]
             [lumo.build.api]
             [lumo.classpath :as classpath]
-            [lumo.core]
+            [lumo.core :as lumo]
             [lumo.io :as io]
             [serverless-lumo.index :as index]))
 
@@ -44,13 +44,19 @@
 (defn compile!
   "Compile ClojureScript using the lumo api."
   [inputs compiler-opts]
-  (js/console.info
-   "Invoking the Lumo compiler w/ inputs"
-   (.stringify js/JSON (clj->js inputs)))
-  (run! classpath/add! inputs)
-  (lumo.build.api/build
-   (apply lumo.build.api/inputs inputs)
-   compiler-opts))
+  (js/Promise.
+   (fn [resolve reject]
+     (js/console.info
+      "Invoking the Lumo compiler w/ inputs"
+      (.stringify js/JSON (clj->js inputs)))
+     (run! classpath/add! inputs)
+     (lumo.build.api/build
+      (apply lumo.build.api/inputs inputs)
+      compiler-opts
+      (fn [result]
+        (if (:error result)
+          (reject result)
+          (resolve result)))))))
 
 (defn read-conf!
   "Read and return the configuration map."
@@ -91,11 +97,11 @@
       (dump-index! (.resolve path output-dir "../index.js")
                    (:functions opts)
                    compiler))
-    (compile! (:source-paths cljs-lambda-opts) compiler)
-    (zip! (:zip-path opts)
-          {:dirs  #{output-dir "node_modules"}
-           :files #{[index {:name "index.js"}]}}
-          compiler)))
+    (.then (compile! (:source-paths cljs-lambda-opts) compiler)
+           (zip! (:zip-path opts)
+                 {:dirs  #{output-dir "node_modules"}
+                  :files #{[index {:name "index.js"}]}}
+                 compiler))))
 
 (def cli-option-map
   {:z :zip-path
@@ -131,6 +137,8 @@
 
 (defn ^:export -main [& args]
   (let [opts (cli-options (cmd-line-args))]
-    (build! opts (merge-maps default-config (read-conf!)))))
+    (.then (build! opts (merge-maps default-config (read-conf!)))
+           lumo/exit
+           #(lumo/exit 1))))
 
 (set! *main-cli-fn* -main)