devtools: warm up namespace cache when switching panels

Namespace cache is used for beautification function names. Unfortunately
devtools is not currently designed to allow async beautification,
so we can properly beautify only if the cache is already populated.

resources/unpacked/devtools/front_end/externs.js

@@ -453,6 +453,10 @@ var dirac = {
 
     initConsole: function() {},
     initRepl: function() {},
+    /**
+     * @param {!WebInspector.Panel} panel
+     */
+    notifyPanelSwitch: function(panel) {},
     getVersion: function() {},
     getRuntimeTag: function() {},
     /**

resources/unpacked/devtools/front_end/ui/InspectorView.js

@@ -346,7 +346,7 @@ WebInspector.InspectorView.prototype = {
         WebInspector.userMetrics.panelShown(panel.name);
         panel.focus();
 
-        dirac.feedback("setCurrentPanel: "+panel.name);
+        dirac.notifyPanelSwitch(panel);
         return panel;
     },
 

src/implant/dirac/implant.cljs

@@ -26,6 +26,9 @@
 (defonce extra-specials #js ["dirac!" "*1" "*2" "*3" "*e"])
 (defonce all-specials (.concat repl-specials extra-specials))
 
+(defn warm-up-namespace-cache! []
+  (ocall (oget js/window "dirac") "extractNamespacesAsync"))
+
 ; -- public API -------------------------------------------------------------------------------------------------------------
 ; following functions will be exposed as helpers for devtools javascript code
 ; they should be called via dirac.something object, see the mapping in dirac-api-to-export below
@@ -86,13 +89,19 @@
 (defn get-repl-specials-async []
   (helpers/resolved-promise all-specials))                                                                                    ; hard-coded for now
 
+(defn notify-panel-switch [panel]
+  (let [panel-name (oget panel "name")]
+    (post-feedback! (str "setCurrentPanel: " panel-name))
+    (warm-up-namespace-cache!)))
+
 ; -- dirac object augumentation ---------------------------------------------------------------------------------------------
 
 ; !!! don't forget to update externs.js when touching this !!!
 (def dirac-api-to-export
   {"feedback"             post-feedback!
    "initConsole"          init-console!
    "initRepl"             init-repl!
+   "notifyPanelSwitch"    notify-panel-switch
    "adoptPrompt"          adopt-prompt!
    "sendEvalRequest"      send-eval-request!
    "getVersion"           get-version
@@ -122,4 +131,4 @@
 
 ; -- intialization ----------------------------------------------------------------------------------------------------------
 
-(runonce (init-implant!))
+(runonce (init-implant!))