fix: enforce first-party popup cap for ads

assets/js/ads-popup-guard.ts

@@ -0,0 +1,158 @@
+export const AD_POPUP_CAP_DURATION_MS = 20 * 60 * 1000
+export const IN_PAGE_PUSH_SEARCH_PARAM_PREFIXES = ['inpage.'] as const
+
+export type PopupOpenKind = 'popunder' | 'in-page-push'
+export type PopupClassification = {
+  kind: PopupOpenKind
+  hostnames?: string[]
+  searchParamPrefixes?: readonly string[]
+}
+
+export type AdPopupCapLogDetails = {
+  lastPopupAt: number | null
+  cappedUntil: number | null
+  remainingMs: number | null
+}
+
+export type PopupGuardDecision = {
+  event: 'allow-in-page-push' | 'allow-popunder' | 'block-capped-popunder'
+  shouldAllow: boolean
+  shouldRecordPopupAt: boolean
+  capLogDetails?: AdPopupCapLogDetails
+  cappedUntil?: number
+}
+
+export type TrustedPopupBypassDecision = {
+  shouldBypassCurrentOpen: boolean
+  nextShouldBypass: boolean
+}
+
+function hostnameMatches(hostname: string, allowedHostnames: string[]): boolean {
+  return allowedHostnames.some(allowedHostname => {
+    return hostname === allowedHostname || hostname.endsWith(`.${allowedHostname}`)
+  })
+}
+
+function hasMatchingSearchParamPrefix(parsedUrl: URL, searchParamPrefixes: readonly string[]): boolean {
+  for (const searchParamKey of parsedUrl.searchParams.keys()) {
+    if (searchParamPrefixes.some(prefix => searchParamKey.startsWith(prefix))) {
+      return true
+    }
+  }
+
+  return false
+}
+
+function matchesPopupClassification(parsedUrl: URL, popupClassification: PopupClassification): boolean {
+  if (popupClassification.hostnames && hostnameMatches(parsedUrl.hostname, popupClassification.hostnames)) {
+    return true
+  }
+
+  if (popupClassification.searchParamPrefixes && hasMatchingSearchParamPrefix(parsedUrl, popupClassification.searchParamPrefixes)) {
+    return true
+  }
+
+  return false
+}
+
+export function getTrustedPopupBypassDecision(shouldBypassNextWindowOpenGuard: boolean): TrustedPopupBypassDecision {
+  return {
+    shouldBypassCurrentOpen: shouldBypassNextWindowOpenGuard,
+    nextShouldBypass: false
+  }
+}
+
+export function getPopupOpenKind(
+  requestedUrl: string | null,
+  {
+    baseUrl,
+    popupClassifications
+  }: {
+    baseUrl: string
+    popupClassifications: readonly PopupClassification[]
+  }
+): PopupOpenKind {
+  if (!requestedUrl) {
+    return 'popunder'
+  }
+
+  try {
+    const parsedUrl = new URL(requestedUrl, baseUrl)
+
+    for (const popupClassification of popupClassifications) {
+      if (matchesPopupClassification(parsedUrl, popupClassification)) {
+        return popupClassification.kind
+      }
+    }
+  } catch {
+    // Ignore malformed vendor URLs and keep the default popunder classification.
+  }
+
+  return 'popunder'
+}
+
+export function isAdPopupCapActive(
+  lastPopupAt: number | null,
+  now: number,
+  capDurationMs = AD_POPUP_CAP_DURATION_MS
+): boolean {
+  return lastPopupAt !== null && now - lastPopupAt < capDurationMs
+}
+
+export function getAdPopupCapLogDetails(
+  lastPopupAt: number | null,
+  now: number,
+  capDurationMs = AD_POPUP_CAP_DURATION_MS
+): AdPopupCapLogDetails {
+  if (lastPopupAt === null) {
+    return {
+      lastPopupAt: null,
+      cappedUntil: null,
+      remainingMs: null
+    }
+  }
+
+  const cappedUntil = lastPopupAt + capDurationMs
+
+  return {
+    lastPopupAt,
+    cappedUntil,
+    remainingMs: Math.max(0, cappedUntil - now)
+  }
+}
+
+export function getPopupGuardDecision({
+  popupOpenKind,
+  lastPopupAt,
+  now,
+  capDurationMs = AD_POPUP_CAP_DURATION_MS
+}: {
+  popupOpenKind: PopupOpenKind
+  lastPopupAt: number | null
+  now: number
+  capDurationMs?: number
+}): PopupGuardDecision {
+  if (popupOpenKind === 'in-page-push') {
+    return {
+      event: 'allow-in-page-push',
+      shouldAllow: true,
+      shouldRecordPopupAt: false
+    }
+  }
+
+  if (isAdPopupCapActive(lastPopupAt, now, capDurationMs)) {
+    return {
+      event: 'block-capped-popunder',
+      shouldAllow: false,
+      shouldRecordPopupAt: false,
+      capLogDetails: getAdPopupCapLogDetails(lastPopupAt, now, capDurationMs)
+    }
+  }
+
+  return {
+    event: 'allow-popunder',
+    shouldAllow: true,
+    shouldRecordPopupAt: true,
+    cappedUntil: now + capDurationMs
+  }
+}

components/layout/FeedbackButton.vue

@@ -3,7 +3,7 @@
   import { project } from '@/config/project'
 
   function handleClick(event: Event) {
-    window.open(`https://feedback.${project.urls.production.hostname}`, '_blank')
+    openTrustedWindow(`https://feedback.${project.urls.production.hostname}`, '_blank')
   }
 </script>
 

components/pages/posts/post/PostSource.vue

@@ -90,7 +90,7 @@
       return
     }
 
-    window.open(url, '_blank')
+    openTrustedWindow(url, '_blank')
   }
 
   function onMenuOpen() {