Fix nested client load directive (#1030)

* escape </script> in string literals

* add changeset

.changeset/fair-dogs-tie.md

@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Properly escapes script tags with nested client:load directives when passing Astro components into framework components via props. Browsers interpret script end tags in strings as script end tags, resulting in syntax errors.

packages/astro/src/internal/__astro_component.ts

@@ -1,12 +1,26 @@
 import type { Renderer, AstroComponentMetadata } from '../@types/astro';
 import hash from 'shorthash';
 import { valueToEstree, Value } from 'estree-util-value-to-estree';
-import { generate } from 'astring';
+import { generate, GENERATOR, Generator } from 'astring';
 import * as astroHtml from './renderer-html';
 
 // A more robust version alternative to `JSON.stringify` that can handle most values
 // see https://github.com/remcohaszing/estree-util-value-to-estree#readme
-const serialize = (value: Value) => generate(valueToEstree(value));
+const customGenerator: Generator = {
+  ...GENERATOR,
+  Literal(node, state) {
+    if (node.raw != null) {
+      // escape closing script tags in strings so browsers wouldn't interpret them as
+      // closing the actual end tag in HTML
+      state.write(node.raw.replace('</script>', '<\\/script>'));
+    } else {
+      GENERATOR.Literal(node, state);
+    }
+  },
+};
+const serialize = (value: Value) => generate(valueToEstree(value), {
+  generator: customGenerator,
+});
 
 export interface RendererInstance {
   source: string | null;