chore: add test util for extracting island data

packages/astro/test/test-utils.js

@@ -242,6 +242,18 @@ export async function loadFixture(inlineConfig) {
 	};
 }
 
+/**
+ * 
+ * @param {string} text
+ * @returns {{ componentUrl: string, componentExport: string, rendererUrl: string, opts: Record<string, unknown>, props: Record<string, unknown> }}
+ */
+export function getIslandDataFromScript(text) {
+	// Island script references `Astro` and `document` globals, so we need to mock them
+	const prelude = [`const Astro = { assign: (_, props) => props }`, `const document = {}`, ''].join(';')
+	// Yes, I know, `eval` is bad! But our data is embedded as JS on purpose.
+	return new Function([prelude, `return ${text}`].join(''))();
+}
+
 /**
  * @param {string} [address]
  */