@ergosphere-it/client

The update state machine of one install, for TypeScript hosts. The host injects the network, the file system, and the clock, so the client runs on any runtime.

What it does

• Checks a channel file, and finds a bundle that this install can take: newer, signed, for this native version, in the rollout and the cohorts.
• Stages a bundle: it reuses files on disk, downloads the rest a few at a time, resumes broken downloads, checks every hash, and builds the bundle directory.
• Selects the bundle to boot, counts boot attempts, and blocks a bundle that never reports healthy.
• Rolls back, records why, and keeps the record until the app dismisses it.
• Checks a channel file for a newer installer, and returns the installer file for this platform in a format that the app takes.

It never runs code. The host loads the bundle that the client selects.

Usage

import { UpdateClient } from '@ergosphere-it/client'
import { createNodeFileSystem } from '@ergosphere-it/client/node'

const client = new UpdateClient({
  channel: 'stable',
  dataDir,
  feedUrl: 'https://updates.example.com',
  fs: createNodeFileSystem(),
  host: 'electron',
  installerBundle,
  nativeVersion: 2,
  platform: 'darwin-arm64',
  product: 'my-app',
  trustedKeys,
})

const selection = await client.boot()
// Load selection.dir, then, when the app works:
await client.markHealthy(selection)

const checked = await client.check()
if (checked.status === 'available')
  await client.stage(checked, { onProgress: ({ downloadedBytes, totalBytes }) => {} })

The API design lists every method and result.

When to use

• You write the host of a new runtime, for example a launcher for another desktop shell.
• You test update behavior without Electron, with a fake network and a temporary directory.

When not to use

• You add updates to an Electron app. Use @ergosphere-it/electron, which runs this client in its launcher.