refactor(nativescript-target): add main template runtime for hot update

nativescript-target/NsJsonpMainTemplate.runtime.js

@@ -0,0 +1,32 @@
+module.exports = function () {
+    function webpackHotUpdateCallback(chunkId, moreModules) {
+        hotAddUpdateChunk(chunkId, moreModules);
+        if (parentHotUpdateCallback) {
+            parentHotUpdateCallback(chunkId, moreModules);
+        }
+    }
+
+    function hotDownloadUpdateChunk(chunkId) {
+        const requestPath = './' + $hotChunkFilename$;
+        try {
+            require(requestPath);
+        } catch (e) {
+            console.log("Hot download for update chunk failed.");
+            console.error(e);
+        }
+    }
+
+    function hotDownloadManifest() {
+        return new Promise(function (resolve, reject) {
+            const requestPath = './' + $hotMainFilename$;
+            try {
+                const update = require(requestPath);
+                resolve(update);
+            } catch (e) {
+                console.log("Hot download for manifest failed.");
+                console.error(e);
+                reject(e);
+            }
+        });
+    }
+};

nativescript-target/NsJsonpMainTemplatePlugin.js

@@ -287,7 +287,7 @@ class NsJsonpMainTemplatePlugin {
                     }
                 );
                 const runtimeSource = Template.getFunctionContent(
-                    require("./JsonpMainTemplate.runtime.js")
+                    require("./NsJsonpMainTemplate.runtime.js")
                 )
                     .replace(/\/\/\$semicolon/g, ";")
                     .replace(/\$require\$/g, mainTemplate.requireFn)