Added test for issue #3544

test/js/samples/class-added-to-element-outside-directive/expected.js

@@ -0,0 +1,83 @@
+/* generated by Svelte vX.Y.Z */
+import {
+	SvelteComponent,
+	append,
+	attr,
+	detach,
+	element,
+	init,
+	insert,
+	noop,
+	safe_not_equal
+} from "svelte/internal";
+
+function add_css() {
+	var style = element("style");
+	style.id = 'svelte-1l99rp3-style';
+	style.textContent = ".root.svelte-1l99rp3 i.svelte-1l99rp3{color:red}";
+	append(document.head, style);
+}
+
+// (8:1) {#if true}
+function create_if_block(ctx) {
+	var span;
+
+	return {
+		c() {
+			span = element("span");
+			span.innerHTML = `<i class="svelte-1l99rp3">hello</i>`;
+			attr(span, "class", "" + (`test`) + " svelte-1l99rp3");
+		},
+
+		m(target, anchor) {
+			insert(target, span, anchor);
+		},
+
+		d(detaching) {
+			if (detaching) {
+				detach(span);
+			}
+		}
+	};
+}
+
+function create_fragment(ctx) {
+	var div;
+
+	var if_block = (true) && create_if_block(ctx);
+
+	return {
+		c() {
+			div = element("div");
+			if (if_block) if_block.c();
+			attr(div, "class", "root svelte-1l99rp3");
+		},
+
+		m(target, anchor) {
+			insert(target, div, anchor);
+			if (if_block) if_block.m(div, null);
+		},
+
+		p: noop,
+		i: noop,
+		o: noop,
+
+		d(detaching) {
+			if (detaching) {
+				detach(div);
+			}
+
+			if (if_block) if_block.d();
+		}
+	};
+}
+
+class Component extends SvelteComponent {
+	constructor(options) {
+		super();
+		if (!document.getElementById("svelte-1l99rp3-style")) add_css();
+		init(this, options, null, create_fragment, safe_not_equal, []);
+	}
+}
+
+export default Component;

test/js/samples/class-added-to-element-outside-directive/input.svelte

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+<style>
+	.root i {
+		color: red;
+	}
+</style>
+
+<div class="root">
+	{#if true}
+		<span class={`test`}>
+			<i>hello</i>
+		</span>
+	{/if}
+</div>