Description

When using Lit SSR and enabling createRenderRoot for a custom element, Lit is rendering the content inside declarative shadow DOM <template> tag.

Steps to Reproduce

1. Given the sample Greeting component that uses createRenderRoot

   import { html, css, LitElement } from 'lit';
   
   export class SimpleGreeting extends LitElement {
     static styles = css`p { color: blue }`;
   
     static properties = {
       name: {type: String},
     };
   
     constructor() {
       super();
       this.name = 'Somebody';
     }
   
     createRenderRoot(){
       return this;
     }
   
     render() {
       return html`<p>Hello, ${this.name}!</p>`;
     }
   }
   
   customElements.define('simple-greeting', SimpleGreeting);

2. Server Render the component

   import { render } from '@lit-labs/ssr/lib/render-with-global-dom-shim.js';
   import { html } from 'lit';
   import './greeting.js';
   
   import Koa from 'koa';
   import koaNodeResolve from 'koa-node-resolve';
   import { Readable } from 'stream';
    
   const { nodeResolve } = koaNodeResolve;
   const app = new Koa();
   const port = 8080;
   
   app.use(async (ctx) => {
     ctx.type = 'text/html';
     ctx.body = Readable.from(render(html`
       <simple-greeting></simple-greeting>
       <simple-greeting name="SSR Works!"></simple-greeting>
     `));
   });
   app.use(nodeResolve({}));
   
   app.listen(port, () => {
     console.log(`Server listening on port ${port}`);
   });

Live Reproduction Link

https://stackblitz.com/github/thescientist13/lit-ssr-create-render-root

Expected Results

No Declarative Shadow DOM would be present, just like in the Lit Playground

<simple-greeting>
    <style>p { color: blue }</style>
    <!--lit-part EvGichL14uw=--><p>Hello, <!--lit-part-->Somebody<!--/lit-part-->!</p><!--/lit-part-->
</simple-greeting>

Actual Results

Declarative Shadow DOM is still rendered

<simple-greeting>
  <template shadowroot="open">
    <style>p { color: blue }</style>
    <!--lit-part EvGichL14uw=--><p>Hello, <!--lit-part-->Somebody<!--/lit-part-->!</p><!--/lit-part-->
  </template>
</simple-greeting>

Browsers Affected

• Chrome
• Firefox
• Edge
• Safari 11
• Safari 10
• IE 11
• NodeJS