fix: missing space when importing run as in migration (#13361)

* fix: missing space when importing run as in migration

* chore: add test

packages/svelte/src/compiler/migrate/index.js

@@ -71,7 +71,7 @@ export function migrate(source) {
 		state = { ...state, scope: analysis.template.scope };
 		walk(parsed.fragment, state, template);
 
-		const run_import = `import { run${state.run_name === 'run' ? '' : `as ${state.run_name}`} } from 'svelte/legacy';`;
+		const run_import = `import { run${state.run_name === 'run' ? '' : ` as ${state.run_name}`} } from 'svelte/legacy';`;
 		let added_legacy_import = false;
 
 		if (state.props.length > 0 || analysis.uses_rest_props || analysis.uses_props) {

packages/svelte/tests/migrate/samples/effects-with-alias-run/input.svelte

@@ -0,0 +1,14 @@
+<script>
+	let count = 0;
+	let run = true;
+	$: console.log(count);
+	$: if (count > 10 && run) {
+		alert('too high')
+	}
+	$: {
+		console.log('foo');
+		if (x) break $;
+		console.log('bar');
+	}
+	$: $count = 1;
+</script>

packages/svelte/tests/migrate/samples/effects-with-alias-run/output.svelte

@@ -0,0 +1,22 @@
+<script>
+	import { run as run_1 } from 'svelte/legacy';
+
+	let count = 0;
+	let run = true;
+	run_1(() => {
+		console.log(count);
+	});
+	run_1(() => {
+		if (count > 10 && run) {
+			alert('too high')
+		}
+	});
+	run_1(() => {
+		console.log('foo');
+		if (x) return;
+		console.log('bar');
+	});
+	run_1(() => {
+		$count = 1;
+	});
+</script>