Use lein instead of custom build

project.clj

@@ -6,7 +6,18 @@
   :dependencies [[org.clojure/clojure "1.8.0"]
                  [org.clojure/clojurescript "1.9.946"]
                  [org.clojure/core.async "0.3.465"]
+                 [org.clojure/core.match "0.3.0-alpha5"]
                  [cljs-ajax "0.7.3"]]
-  :source-paths ["src_clj"]
-  :main looped-in.build
-  :aliases {"build" ["run"]})
+  :plugins [[lein-cljsbuild "1.1.7"]]
+  :cljsbuild {:builds [{:source-paths ["src"]
+                        :compiler {:optimizations :simple
+                                   :source-map true
+                                   :pretty-print true
+                                   :output-dir "ext/js/generated/out"
+                                   :modules
+                                   {:content
+                                    {:output-to "ext/js/generated/content.js"
+                                     :entries #{"looped-in.content"}}
+                                    :background
+                                    {:output-to "ext/js/generated/background.js"
+                                     :entries #{"looped-in.background"}}}}}]})

src/looped_in/background.cljs

@@ -0,0 +1,40 @@
+(ns looped-in.background
+  (:require [clojure.core.match :refer [match]]
+            [cljs.core.async :refer [go chan >! <!]]
+            [ajax.core :refer [GET]]
+            [looped-in.logging :as log]
+            [looped-in.promises :refer [channel->promise]]))
+
+(enable-console-print!)
+
+(def browser-action (.-browserAction js/browser))
+
+(defn fetch-submission
+  "Fetches submissions from Hacker News by `url`"
+  [url]
+  (let [response-chan (chan)]
+    (GET "https://hn.algolia.com/api/v1/search"
+         {:params {"query" url
+                   "hitsPerPage" 1000
+                   "restrictSearchableAttributes" "url"}
+          :handler (fn [res] (go (>! response-chan res)))
+          :error-handler (fn [err] (log/error "Error fetching HN stories:"
+                                              (clj->js err)))})
+    response-chan))
+
+(defn handle-message
+  "Handles messages from the content script"
+  [msg]
+  (match (.-type msg)
+         "fetchData" (channel->promise (fetch-submission (.-url msg)))
+         x (log/warn "Ignoring unknown message type" x)))
+
+(-> js/browser
+    (.-runtime)
+    (.-onMessage)
+    (.addListener handle-message
+     #_(fn [msg]
+         (prn msg)
+         (.setBadgeBackgroundColor browser-action #js {:color "#232323"})
+         (.setBadgeText browser-action
+                        #js {:text (str (.-numComments msg))}))))

src/looped_in/content.cljs

@@ -1,24 +1,12 @@
 (ns looped-in.content
   (:require-macros [cljs.core.async.macros :refer [go]])
   (:require [ajax.core :refer [GET]]
-            [cljs.core.async :as async :refer [chan <! >!]]
-            [looped-in.logging :as log]))
+            [cljs.core.async :as async :refer [go <!]]
+            [looped-in.logging :as log]
+            [looped-in.promises :refer [promise->channel]]))
 
 (enable-console-print!)
 
-(defn fetch-submission
-  "Fetches submissions from Hacker News by `url`"
-  [url]
-  (let [response-chan (chan)]
-    (GET "https://hn.algolia.com/api/v1/search"
-         {:params {"query" url
-                   "hitsPerPage" 1000
-                   "restrictSearchableAttributes" "url"}
-          :handler (fn [res] (go (>! response-chan res)))
-          :error-handler (fn [err] (log/error "Error fetching HN stories:"
-                                          (clj->js err)))})
-    response-chan))
-
 (defn filter-response
   "Filters a response from hn.algolia.com to give just the relevant results"
   ;; TODO implement a cache by URL and timestamp that caches the results of the
@@ -47,9 +35,16 @@
         (.-runtime)
         (.sendMessage #js {:numComments num-comments}))))
 
-(let [current-url (-> js/window (.-location) (.-href))
+#_(let [current-url (-> js/window (.-location) (.-href))
       sub-chan (fetch-submission current-url)]
   (go (->> (<! sub-chan)
            (filter-response current-url)
            (sort-hits)
            (handle-hits))))
+
+(let [current-url (-> js/window (.-location) (.-href))
+      results-chan (-> js/browser
+                       (.-runtime)
+                       (.sendMessage #js {:type "fetchData" :url current-url})
+                       (promise->channel))]
+  (go (log/debug "results:" (<! results-chan))))

src/looped_in/promises.cljs

@@ -0,0 +1,21 @@
+(ns looped-in.promises
+  (:require [cljs.core.async :refer [go chan >! <!]]
+            [looped-in.logging :as log]))
+
+(defn channel->promise
+  "Returns a Promise that resolves by taking from the channel"
+  [channel]
+  (js/Promise. (fn [resolve]
+                 (go (let [result (clj->js (<! channel))]
+                       (resolve result))))))
+
+(defn promise->channel
+  "Returns a channel that is put into when the Promise resolves"
+  [p]
+  (let [channel (chan)]
+    (-> p
+        (.then (fn [result]
+                 (go (>! channel result))))
+        (.err (fn [err]
+                (log/error "Error resolving Promise:" err))))
+    channel))

src_clj/looped_in/build.clj

@@ -1,12 +0,0 @@
-(ns looped-in.build
-  (:require [cljs.build.api :as cljs]))
-
-(defn -main [& args]
-  (cljs/build "src_cljs" {:optimizations :simple
-                          :source-map true
-                          :pretty-print true
-                          :output-dir "ext/js/generated/out"
-                          :modules {:content {:output-to "ext/js/generated/content.js"
-                                              :entries #{"looped-in.content"}}
-                                    :background {:output-to "ext/js/generated/background.js"
-                                                 :entries #{"looped-in.background"}}}}))

src_cljs/looped_in/background.cljs

@@ -1,14 +0,0 @@
-(ns looped-in.background)
-
-(enable-console-print!)
-
-(def browser-action (.-browserAction js/browser))
-
-(-> js/browser
-    (.-runtime)
-    (.-onMessage)
-    (.addListener (fn [msg]
-                    (prn msg)
-                    (.setBadgeBackgroundColor browser-action #js {:color "#232323"})
-                    (.setBadgeText browser-action
-                                   #js {:text (str (.-numComments msg))}))))