remove <!--ssr:each_else--> comments

Author: Rich-Harris

packages/svelte/src/compiler/phases/3-transform/server/transform-server.js

@@ -1500,24 +1500,28 @@ const template_visitors = {
 			b.update('++', index, false),
 			b.block(each)
 		);
+
+		const close = b.stmt(b.assignment('+=', b.id('$$payload.out'), b.literal(BLOCK_CLOSE)));
+
 		if (node.fallback) {
-			const fallback_stmts = create_block(node, node.fallback.nodes, context);
-			fallback_stmts.unshift(
-				b.stmt(b.assignment('+=', b.id('$$payload.out'), b.literal('<!ssr:each_else>')))
+			const fallback = create_block(node, node.fallback.nodes, context);
+
+			fallback.push(
+				b.stmt(b.assignment('+=', b.id('$$payload.out'), b.literal(`<!--${HYDRATION_END}!-->`)))
 			);
+
 			state.template.push(
 				t_statement(
 					b.if(
 						b.binary('!==', b.member(array_id, b.id('length')), b.literal(0)),
-						for_loop,
-						b.block(fallback_stmts)
+						b.block([for_loop, close]),
+						b.block(fallback)
 					)
 				)
 			);
 		} else {
-			state.template.push(t_statement(for_loop));
+			state.template.push(t_statement(for_loop), t_statement(close));
 		}
-		state.template.push(block_close);
 	},
 	IfBlock(node, context) {
 		const state = context.state;

packages/svelte/src/internal/client/dom/blocks/each.js

@@ -5,6 +5,7 @@ import {
 	EACH_IS_STRICT_EQUALS,
 	EACH_ITEM_REACTIVE,
 	EACH_KEYED,
+	HYDRATION_END,
 	HYDRATION_START
 } from '../../../../constants.js';
 import { hydrate_anchor, hydrate_nodes, hydrating, set_hydrating } from '../hydration.js';
@@ -97,16 +98,13 @@ function each(anchor, flags, get_collection, get_key, render_fn, fallback_fn, re
 		let mismatch = false;
 
 		if (hydrating) {
-			var is_else = /** @type {Comment} */ (hydrate_nodes?.[0])?.data === 'ssr:each_else';
+			var is_else = /** @type {Comment} */ (anchor).data === `${HYDRATION_END}!`;
 
 			if (is_else !== (length === 0)) {
 				// hydration mismatch — remove the server-rendered DOM and start over
 				remove(hydrate_nodes);
 				set_hydrating(false);
 				mismatch = true;
-			} else if (is_else) {
-				// Remove the each_else comment node or else it will confuse the subsequent hydration algorithm
-				/** @type {import('#client').TemplateNode[]} */ (hydrate_nodes).shift();
 			}
 		}
 

packages/svelte/tests/snapshot/samples/each-string-template/_expected/server/index.svelte.js

@@ -17,6 +17,6 @@ export default function Each_string_template($$payload, $$props) {
 		$$payload.out += "<!--]-->";
 	}
 
-	$$payload.out += `<!--]-->`;
+	$$payload.out += "<!--]-->";
 	$.pop();
 }