enclose text/compound slot attributes in backticks - fixes #2061

src/utils/get_slot_data.ts

@@ -11,7 +11,7 @@ export default function(attributes) {
 					? '""'
 					: attribute.chunks.length === 1 && attribute.chunks[0].type !== 'Text'
 						? snip(attribute.chunks[0])
-						: stringify_attribute(attribute);
+						: '`' + stringify_attribute(attribute) + '`';
 
 			return `${attribute.name}: ${value}`;
 		});

test/runtime/samples/component-slot-let-static/Nested.html

@@ -0,0 +1 @@
+<slot value="Hi" />

test/runtime/samples/component-slot-let-static/_config.js

@@ -0,0 +1,3 @@
+export default {
+	html: `<p>Hi</p>`
+};

test/runtime/samples/component-slot-let-static/main.html

@@ -0,0 +1,7 @@
+<script>
+	import Nested from './Nested.html';
+</script>
+
+<Nested let:value>
+	<p>{value}</p>
+</Nested>