always attach fragment to shadow root (fixes #821)

src/generators/dom/index.ts

@@ -208,6 +208,12 @@ export default function dom(
 
 		this._fragment = @create_main_fragment(this._state, this);
 
+		${generator.customElement ? deindent`
+			this._fragment.create();
+			this._fragment.${block.hasIntroMethod ? 'intro' : 'mount'}(this.shadowRoot, null);
+
+			if (options.target) this._mount(options.target, options.anchor || null);
+		` : deindent`
 			if (options.target) {
 				${generator.hydratable
 					? deindent`
@@ -219,9 +225,7 @@ export default function dom(
 						${options.dev && `if (options.hydrate) throw new Error("options.hydrate only works if the component was compiled with the \`hydratable: true\` option");`}
 						this._fragment.create();
 					`}
-			${generator.customElement ?
+				this._fragment.${block.hasIntroMethod ? 'intro' : 'mount'}(options.target, options.anchor || null);
-				`this._mount(options.target, options.anchor || null);` :
-				`this._fragment.${block.hasIntroMethod ? 'intro' : 'mount'}(options.target, options.anchor || null);`}
 
 				${(generator.hasComponents || generator.hasComplexBindings || templateProperties.oncreate || generator.hasIntroTransitions) && deindent`
 					${generator.hasComponents && `this._lock = true;`}
@@ -231,6 +235,9 @@ export default function dom(
 					${generator.hasComponents && `this._lock = false;`}
 				`}
 			}
+		`}
+
+
 	`;
 
 	if (generator.customElement) {
@@ -272,7 +279,6 @@ export default function dom(
 			customElements.define("${generator.tag}", ${name});
 			@assign(${prototypeBase}, ${proto}, {
 				_mount(target, anchor) {
-					this._fragment.${block.hasIntroMethod ? 'intro' : 'mount'}(this.shadowRoot, null);
 					target.insertBefore(this, anchor);
 				},