chore: add chat example (#840)

examples/chat/test.js

@@ -0,0 +1,77 @@
+'use strict'
+
+const path = require('path')
+const execa = require('execa')
+const pDefer = require('p-defer')
+const uint8ArrayToString = require('uint8arrays/to-string')
+
+function startProcess(name) {
+  return execa('node', [path.join(__dirname, name)], {
+    cwd: path.resolve(__dirname),
+    all: true
+  })
+}
+
+async function test () {
+  const message = 'test message'
+  let listenerOutput = ''
+  let dialerOutput = ''
+
+  let isListening = false
+  let messageSent = false
+  const listenerReady = pDefer()
+  const dialerReady = pDefer()
+  const messageReceived = pDefer()
+
+  // Step 1 process
+  process.stdout.write('node listener.js\n')
+  const listenerProc = startProcess('src/listener.js')
+  listenerProc.all.on('data', async (data) => {
+    process.stdout.write(data)
+
+    listenerOutput += uint8ArrayToString(data)
+
+    if (!isListening && listenerOutput.includes('Listener ready, listening on')) {
+      listenerReady.resolve()
+      isListening = true
+    } else if (isListening && listenerOutput.includes(message)) {
+      messageReceived.resolve()
+    }
+  })
+
+  await listenerReady.promise
+  process.stdout.write('==================================================================\n')
+
+  // Step 2 process
+  process.stdout.write('node dialer.js\n')
+  const dialerProc = startProcess('src/dialer.js')
+  dialerProc.all.on('data', async (data) => {
+    process.stdout.write(data)
+    dialerOutput += uint8ArrayToString(data)
+
+    if (!messageSent && dialerOutput.includes('Type a message and see what happens')) {
+      dialerReady.resolve()
+      dialerProc.stdin.write(message)
+      dialerProc.stdin.write('\n')
+      messageSent = true
+    }
+  })
+
+  await dialerReady.promise
+  process.stdout.write('==================================================================\n')
+  await messageReceived.promise
+  process.stdout.write('chat message received\n')
+
+  listenerProc.kill()
+  dialerProc.kill()
+  await Promise.all([
+    listenerProc,
+    dialerProc
+  ]).catch((err) => {
+    if (err.signal !== 'SIGTERM') {
+      throw err
+    }
+  })
+}
+
+module.exports = test