roughed out default slot

src/compiler/compile/Component.ts

@@ -160,6 +160,9 @@ export default class Component {
 			}
 			this.tag = this.component_options.tag || compile_options.tag;
 			this.compile_options.shadowDom = this.component_options.shadowdom || "open";
+			if(this.compile_options.shadowDom === "none"){
+				// handle slots here?
+			}
 		} else {
 			this.tag = this.name.name;
 		}

src/runtime/internal/Component.ts

@@ -165,11 +165,14 @@ export let SvelteElement;
 if (typeof HTMLElement === 'function') {
 	SvelteElement = class extends HTMLElement {
 		$$: T$$;
+		private _content;
 		constructor() {
 			super();
+			this._copycontent()
 		}
 
 		connectedCallback() {
+			this._slotcontent()
 			// @ts-ignore todo: improve typings
 			for (const key in this.$$.slotted) {
 				// @ts-ignore todo: improve typings
@@ -177,6 +180,24 @@ if (typeof HTMLElement === 'function') {
 			}
 		}
 
+		_copycontent(){
+			if(this.children){
+				this._content = document.createElement("div")
+				while(this.childNodes.length > 0){
+					this._content.appendChild(this.childNodes[0])
+				}
+			}
+		}
+
+		_slotcontent(){
+			if(this._content){
+				const slot = this.querySelector("slot")
+				while(this._content.childNodes.length > 0){
+					slot.appendChild(this._content.childNodes[0])
+				}
+			}
+		}
+
 		attributeChangedCallback(attr, _oldValue, newValue) {
 			this[attr] = newValue;
 		}

test/custom-elements/samples/shadowdom-none-slots/main.svelte

@@ -0,0 +1,11 @@
+<svelte:options tag="custom-element" shadowdom="none" />
+
+<div>
+	<slot>
+		<p>default fallback content</p>
+	</slot>
+
+	<slot name='foo'>
+		<p>foo fallback content</p>
+	</slot>
+</div>

test/custom-elements/samples/shadowdom-none-slots/test.js

@@ -0,0 +1,17 @@
+import * as assert from 'assert';
+import './main.svelte';
+
+export default function (target) {
+	target.innerHTML = `
+		<custom-element>
+			<strong>slotted</strong>
+		</custom-element>`;
+
+	const el = target.querySelector('custom-element');
+
+	const div = el.children[0];
+	const [slot0] = div.children;
+
+	assert.equal(slot0.children[1], target.querySelector('strong'));
+	//assert.equal(slot1.assignedNodes().length, 0);
+}