feat: more o11y for i18n pojo (#5148)

apps/frontend/src/plugins/payload-debugger.ts

@@ -0,0 +1,37 @@
+function findNonPOJOs(
+	obj: unknown,
+	path: string,
+	found: Array<{ path: string; type: string }> = [],
+): Array<{ path: string; type: string }> {
+	if (obj === null || typeof obj !== 'object') return found
+
+	const proto = Object.getPrototypeOf(obj)
+	if (proto !== Object.prototype && proto !== null && !Array.isArray(obj)) {
+		found.push({ path, type: obj.constructor?.name ?? 'Unknown' })
+	}
+
+	for (const [key, value] of Object.entries(obj)) {
+		findNonPOJOs(value, `${path}.${key}`, found)
+	}
+
+	return found
+}
+
+export default defineNuxtPlugin((nuxtApp) => {
+	if (!import.meta.dev || !import.meta.server) return
+
+	nuxtApp.hooks.hook('app:rendered', () => {
+		try {
+			JSON.stringify(nuxtApp.payload)
+		} catch (e) {
+			console.error('[payload-debugger] Payload serialization would fail:', e)
+			const nonPOJOs = findNonPOJOs(nuxtApp.payload, 'payload')
+			if (nonPOJOs.length > 0) {
+				console.error('[payload-debugger] Non-POJO objects found in payload:')
+				for (const { path, type } of nonPOJOs) {
+					console.error(`  - ${path}: ${type}`)
+				}
+			}
+		}
+	})
+})