test(iframe): [PKG-IFRAME-05] verify native cached history and interrupted navigation

test/history/observe.js

@@ -0,0 +1,16 @@
+window.documentWitness = Math.random().toString(36)
+window.lifecycle = []
+window.fixtureErrors = []
+for (const name of ['pageshow', 'pagehide']) {
+  addEventListener(name, event => window.lifecycle.push({ type: event.type, persisted: event.persisted }))
+}
+addEventListener('error', event => window.fixtureErrors.push(event.message))
+addEventListener('unhandledrejection', event => window.fixtureErrors.push(String(event.reason)))
+addEventListener('message', (event) => {
+  if (window === window.parent || event.source !== window.parent)
+    return
+  if (event.data?.type === 'history-fixture-finish') {
+    window.parent.postMessage({ type: 'history-fixture-old-document', data: { witness: window.documentWitness, executions: window.executions || 0 } }, '*')
+    window.finishHeld()
+  }
+})