fix: address refactor comments

src/render/emitter.ts

@@ -1,3 +1,5 @@
+import { stringify, toValue } from '../util/underscore'
+
 export class Emitter {
   public html: any = '';
   public break = false;
@@ -9,6 +11,11 @@ export class Emitter {
   }
 
   public write (html: any) {
+    if (this.keepOutputType === true) {
+      html = toValue(html)
+    } else {
+      html = stringify(toValue(html))
+    }
     // This will only preserve the type if the value is isolated.
     // I.E:
     // {{ my-port }} -> 42

src/render/render.ts

@@ -4,7 +4,10 @@ import { Template } from '../template/template'
 import { Emitter } from './emitter'
 
 export class Render {
-  public * renderTemplates (templates: Template[], ctx: Context, emitter: Emitter): IterableIterator<any> {
+  public * renderTemplates (templates: Template[], ctx: Context, emitter?: Emitter): IterableIterator<any> {
+    if (!emitter) {
+      emitter = new Emitter(ctx.opts.keepOutputType)
+    }
     for (const tpl of templates) {
       try {
         const html = yield tpl.render(ctx, emitter)