initial commit

backend/lib/is-online.mjs

@@ -0,0 +1,34 @@
+import isOnline from 'is-online'
+import { Readable } from 'streamx'
+
+import { action, CONNECTIVITY } from '../state.mjs'
+
+export class ConnectivityCheck extends Readable {
+  constructor (opts = {}) {
+    super()
+    this.opts = opts
+    this.retryInterval = opts.retryInterval || 2000
+    this._action({ internet: false })
+    this._update()
+  }
+
+  async _update () {
+    try {
+      const hasInternet = await isOnline(this.opts)
+      this._action({ internet: hasInternet })
+    } catch (err) {
+      this._action({ internet: false })
+    } finally {
+      this._timeout = setTimeout(() => this._update(), this.retryInterval)
+    }
+  }
+
+  _destroy () {
+    if (this._timeout) clearTimeout(this._timeout)
+  }
+
+  _action (data) {
+    if (this.destroyed) return
+    this.push(action(CONNECTIVITY, data))
+  }
+}