Create a stand-alone paskia npm package (paskia-js). Make the frontend use it (but from source tree to keep synced).

paskia-js/src/validate.ts

@@ -0,0 +1,66 @@
+import { apiJson } from './fetch'
+
+const POLL_INTERVAL = 60 * 1000
+const IDLE_TIMEOUT = 5 * 60 * 1000
+
+export class SessionValidator {
+  private userUuidGetter: () => string | undefined
+  private onSessionLost: (error: Error) => void
+  private pollTimer: ReturnType<typeof setInterval> | null = null
+  private idleTimer: ReturnType<typeof setTimeout> | null = null
+  private active = false
+
+  constructor(userUuidGetter: () => string | undefined, onSessionLost: (error: Error) => void) {
+    this.userUuidGetter = userUuidGetter
+    this.onSessionLost = onSessionLost
+    this.resetIdleTimer = this.resetIdleTimer.bind(this)
+  }
+
+  resetIdleTimer(): void {
+    if (this.idleTimer) clearTimeout(this.idleTimer)
+    if (!this.active) this.startPolling()
+    this.idleTimer = setTimeout(() => this.stopPolling(), IDLE_TIMEOUT)
+  }
+
+  async validate(): Promise<void> {
+    try {
+      const data = await apiJson<{ ctx?: { user?: { uuid?: string } } }>('/auth/api/validate', { method: 'POST' })
+      const newUuid = data.ctx?.user?.uuid
+      if (newUuid !== this.userUuidGetter()) {
+        window.location.reload()
+      }
+    } catch (error) {
+      if ((error as Error).name !== 'NetworkError') {
+        this.stopPolling()
+        this.onSessionLost(error as Error)
+      }
+    }
+  }
+
+  startPolling(): void {
+    if (this.active) return
+    this.active = true
+    this.pollTimer = setInterval(() => this.validate(), POLL_INTERVAL)
+  }
+
+  stopPolling(): void {
+    this.active = false
+    if (this.pollTimer) {
+      clearInterval(this.pollTimer)
+      this.pollTimer = null
+    }
+  }
+
+  start(): void {
+    window.addEventListener('pointermove', this.resetIdleTimer)
+    window.addEventListener('pointerdown', this.resetIdleTimer)
+    this.resetIdleTimer()
+  }
+
+  stop(): void {
+    window.removeEventListener('pointermove', this.resetIdleTimer)
+    window.removeEventListener('pointerdown', this.resetIdleTimer)
+    if (this.idleTimer) clearTimeout(this.idleTimer)
+    this.stopPolling()
+  }
+}