chore: extract a couple of drive-by fixes from other branch (#16772)

* chore: extract a couple of drive-by fixes from other branch

* more

packages/svelte/src/internal/client/dom/operations.js

@@ -130,11 +130,11 @@ export function child(node, is_text) {
 
 /**
  * Don't mark this as side-effect-free, hydration needs to walk all nodes
- * @param {DocumentFragment | TemplateNode[]} fragment
- * @param {boolean} is_text
+ * @param {DocumentFragment | TemplateNode | TemplateNode[]} fragment
+ * @param {boolean} [is_text]
  * @returns {Node | null}
  */
-export function first_child(fragment, is_text) {
+export function first_child(fragment, is_text = false) {
 	if (!hydrating) {
 		// when not hydrating, `fragment` is a `DocumentFragment` (the result of calling `open_frag`)
 		var first = /** @type {DocumentFragment} */ (get_first_child(/** @type {Node} */ (fragment)));

packages/svelte/src/internal/client/dom/template.js

@@ -316,6 +316,9 @@ export function text(value = '') {
 	return node;
 }
 
+/**
+ * @returns {TemplateNode | DocumentFragment}
+ */
 export function comment() {
 	// we're not delegating to `template` here for performance reasons
 	if (hydrating) {

packages/svelte/src/internal/client/reactivity/batch.js

@@ -10,12 +10,10 @@ import {
 	INERT,
 	RENDER_EFFECT,
 	ROOT_EFFECT,
-	USER_EFFECT,
 	MAYBE_DIRTY
 } from '#client/constants';
 import { async_mode_flag } from '../../flags/index.js';
 import { deferred, define_property } from '../../shared/utils.js';
-import { get_boundary } from '../dom/blocks/boundary.js';
 import {
 	active_effect,
 	is_dirty,
@@ -30,7 +28,6 @@ import { DEV } from 'esm-env';
 import { invoke_error_boundary } from '../error-handling.js';
 import { old_values } from './sources.js';
 import { unlink_effect } from './effects.js';
-import { unset_context } from './async.js';
 
 /** @type {Set<Batch>} */
 const batches = new Set();