fix(i18n): persist CMS translations and validate message catalogs

src/lib/cms-message-validation.ts

@@ -0,0 +1,36 @@
+import {
+	type MessageFormatElement,
+	parse,
+	TYPE,
+} from "@formatjs/icu-messageformat-parser";
+
+/** Argument names and rich-text tags are a contract with the calling component. */
+export function messageVariables(value: string): string[] {
+	const names = new Set<string>();
+	function visit(nodes: MessageFormatElement[]) {
+		for (const node of nodes) {
+			if (node.type !== TYPE.literal && node.type !== TYPE.pound)
+				names.add(node.value);
+			if (node.type === TYPE.select || node.type === TYPE.plural) {
+				for (const option of Object.values(node.options)) visit(option.value);
+			}
+			if (node.type === TYPE.tag) visit(node.children);
+		}
+	}
+	visit(parse(value));
+	return [...names].sort();
+}
+export function validateCmsMessage(
+	value: string,
+	source: string,
+): "empty" | "invalid" | "variables" | null {
+	if (!value.trim()) return "empty";
+	try {
+		return messageVariables(value).join("\0") ===
+			messageVariables(source).join("\0")
+			? null
+			: "variables";
+	} catch {
+		return "invalid";
+	}
+}