feat: migrate to RSPack (#2131)

* Migrate to RSPack
* Add tests to CI, address coverage
* fix: Restore AWS sdk
* add simple serve

lib/handlebars.runtime.js

@@ -19,7 +19,10 @@ function create() {
   hb.Utils = Utils;
   hb.escapeExpression = Utils.escapeExpression;
 
-  hb.VM = runtime;
+  // Spread into a plain object so that runtime functions (e.g. checkRevision)
+  // can be overridden by consumers. ES module namespace objects are sealed with
+  // getter-only properties per spec, which would prevent monkey-patching.
+  hb.VM = { ...runtime };
   hb.template = function (spec) {
     return runtime.template(spec, hb);
   };

lib/precompiler.js

@@ -1,7 +1,7 @@
 /* eslint-disable no-console */
 import Async from 'neo-async';
 import fs from 'fs';
-import * as Handlebars from './handlebars';
+import Handlebars from './handlebars';
 import { basename } from 'path';
 import { SourceMapConsumer, SourceNode } from 'source-map';