Fix bug on iOS platform occurring when application is built in release mode with development environment. In this case, before this patch, the plugin copies firebase prod file in place of the firebase dev file.

Author: Danilo De Luca

publish/scripts/installer.js

@@ -837,16 +837,21 @@ module.exports = function($logger, hookArgs) {
 
         var isReleaseBuild = !!((hookArgs.checkForChangesOpts && hookArgs.checkForChangesOpts.projectChangesOptions) || hookArgs.prepareData).release;
         var validProdEnvs = ['prod','production'];
+        var validStagingEnvs = ["dev", "development", "staging"];
+        var isStagingEnv = false;
         var isProdEnv = false; // building with --env.prod or --env.production flag
 
         var env = ((hookArgs.checkForChangesOpts && hookArgs.checkForChangesOpts.projectData && hookArgs.checkForChangesOpts.projectData.$options && hookArgs.checkForChangesOpts.projectData.$options.argv) || hookArgs.prepareData).env;
         if (env) {
             Object.keys(env).forEach((key) => {
                 if (validProdEnvs.indexOf(key)>-1) { isProdEnv=true; }
+                if (validStagingEnvs.indexOf(key) > -1) { isStagingEnv = true; }
             });
+            
+            
         }
 
-        var buildType = (isReleaseBuild && isProdEnv) || (!isReleaseBuild && isProdEnv) ? 'production' : 'development';
+        var buildType = (isReleaseBuild && !isStagingEnv) || isProdEnv ? 'production' : 'development';
 
         /*
             Detect if we have nativescript-plugin-firebase temp file created during after-prepare hook, so we know