diff --git a/src/compiler/compile/nodes/shared/map_children.ts b/src/compiler/compile/nodes/shared/map_children.ts
index a8696c4f01..6f2a0dcf25 100644
--- a/src/compiler/compile/nodes/shared/map_children.ts
+++ b/src/compiler/compile/nodes/shared/map_children.ts
@@ -1,96 +1,101 @@
-import AwaitBlock from '../AwaitBlock';
-import Body from '../Body';
-import ConstTag from '../ConstTag';
-import Comment from '../Comment';
-import EachBlock from '../EachBlock';
-import Document from '../Document';
-import Element from '../Element';
-import Head from '../Head';
-import IfBlock from '../IfBlock';
-import InlineComponent from '../InlineComponent';
-import KeyBlock from '../KeyBlock';
-import MustacheTag from '../MustacheTag';
-import Options from '../Options';
-import RawMustacheTag from '../RawMustacheTag';
-import DebugTag from '../DebugTag';
-import Slot from '../Slot';
-import SlotTemplate from '../SlotTemplate';
-import Text from '../Text';
-import Title from '../Title';
-import Window from '../Window';
-import { TemplateNode } from '../../../interfaces';
-import { push_array } from '../../../utils/push_array';
-
-export type Children = ReturnType<typeof map_children>;
+import AwaitBlock from '../AwaitBlock.js';
+import Body from '../Body.js';
+import ConstTag from '../ConstTag.js';
+import Comment from '../Comment.js';
+import EachBlock from '../EachBlock.js';
+import Document from '../Document.js';
+import Element from '../Element.js';
+import Head from '../Head.js';
+import IfBlock from '../IfBlock.js';
+import InlineComponent from '../InlineComponent.js';
+import KeyBlock from '../KeyBlock.js';
+import MustacheTag from '../MustacheTag.js';
+import Options from '../Options.js';
+import RawMustacheTag from '../RawMustacheTag.js';
+import DebugTag from '../DebugTag.js';
+import Slot from '../Slot.js';
+import SlotTemplate from '../SlotTemplate.js';
+import Text from '../Text.js';
+import Title from '../Title.js';
+import Window from '../Window.js';
+import { push_array } from '../../../utils/push_array.js';
 
+/** @param {any} type */
 function get_constructor(type) {
-	switch (type) {
-		case 'AwaitBlock':
-			return AwaitBlock;
-		case 'Body':
-			return Body;
-		case 'Comment':
-			return Comment;
-		case 'ConstTag':
-			return ConstTag;
-		case 'Document':
-			return Document;
-		case 'EachBlock':
-			return EachBlock;
-		case 'Element':
-			return Element;
-		case 'Head':
-			return Head;
-		case 'IfBlock':
-			return IfBlock;
-		case 'InlineComponent':
-			return InlineComponent;
-		case 'KeyBlock':
-			return KeyBlock;
-		case 'MustacheTag':
-			return MustacheTag;
-		case 'Options':
-			return Options;
-		case 'RawMustacheTag':
-			return RawMustacheTag;
-		case 'DebugTag':
-			return DebugTag;
-		case 'Slot':
-			return Slot;
-		case 'SlotTemplate':
-			return SlotTemplate;
-		case 'Text':
-			return Text;
-		case 'Title':
-			return Title;
-		case 'Window':
-			return Window;
-		default:
-			throw new Error(`Not implemented: ${type}`);
-	}
+    switch (type) {
+        case 'AwaitBlock':
+            return AwaitBlock;
+        case 'Body':
+            return Body;
+        case 'Comment':
+            return Comment;
+        case 'ConstTag':
+            return ConstTag;
+        case 'Document':
+            return Document;
+        case 'EachBlock':
+            return EachBlock;
+        case 'Element':
+            return Element;
+        case 'Head':
+            return Head;
+        case 'IfBlock':
+            return IfBlock;
+        case 'InlineComponent':
+            return InlineComponent;
+        case 'KeyBlock':
+            return KeyBlock;
+        case 'MustacheTag':
+            return MustacheTag;
+        case 'Options':
+            return Options;
+        case 'RawMustacheTag':
+            return RawMustacheTag;
+        case 'DebugTag':
+            return DebugTag;
+        case 'Slot':
+            return Slot;
+        case 'SlotTemplate':
+            return SlotTemplate;
+        case 'Text':
+            return Text;
+        case 'Title':
+            return Title;
+        case 'Window':
+            return Window;
+        default:
+            throw new Error(`Not implemented: ${type}`);
+    }
 }
 
-export default function map_children(component, parent, scope, children: TemplateNode[]) {
-	let last = null;
-	let ignores = [];
-
-	return children.map((child) => {
-		const constructor = get_constructor(child.type);
-
-		const use_ignores = child.type !== 'Text' && child.type !== 'Comment' && ignores.length;
-
-		if (use_ignores) component.push_ignores(ignores);
-		const node = new constructor(component, parent, scope, child);
-		if (use_ignores) component.pop_ignores(), (ignores = []);
+/**
+ * @param {any} component
+ * @param {any} parent
+ * @param {any} scope
+ * @param {import('../../../interfaces.js').TemplateNode[]} children
+ */
+export default function map_children(component, parent, scope, children) {
+    let last = null;
+    let ignores = [];
+    return children.map(/** @param {any} child */ (child) => {
+        const constructor = get_constructor(child.type);
+        const use_ignores = child.type !== 'Text' && child.type !== 'Comment' && ignores.length;
+        if (use_ignores)
+            component.push_ignores(ignores);
+        const node = new constructor(component, parent, scope, child);
+        if (use_ignores)
+            component.pop_ignores(), (ignores = []);
+        if (node.type === 'Comment' && node.ignores.length) {
+            push_array(ignores, node.ignores);
+        }
+        if (last)
+            last.next = node;
+        node.prev = last;
+        last = node;
+        return node;
+    });
+}
 
-		if (node.type === 'Comment' && node.ignores.length) {
-			push_array(ignores, node.ignores);
-		}
 
-		if (last) last.next = node;
-		node.prev = last;
-		last = node;
+/** @typedef {Class<map_children>>} Children */
 
-		return node;
-	});
-}