refactor startup and shutdown

src/check.js

@@ -1,5 +1,6 @@
 import notify from './notification/index.js'
 import sites from './sites/index.js'
+import wait from './utils/wait.js'
 import {
   LOOP_INTERVAL, SEARCH,
 } from '../privateConfig.js'
@@ -57,7 +58,7 @@ const startChecking = async (browser) => {
 
     const pauseDuration = Math.round(INTERVAL_MS / sites.length)
     console.log(`⏳ Sites will be checked again in ~${Math.round(pauseDuration / 1000)} seconds.`)
-    await page.waitForTimeout(pauseDuration)
+    await wait(pauseDuration)
   }
 }
 

src/index.js

@@ -1,43 +1,50 @@
 import puppeteer from 'puppeteer'
-import readline from 'readline'
 
 import logger from './utils/logger.js'
 import startChecking from './check.js'
 import {
   HIDE_BROWSER, BROWSER_SIZE,
 } from '../privateConfig.js'
 
-// TODO: This isn't working as intended. I'm not sure it's even being invoked.
-const shutDown = async (browser) => {
-  logger.log('🏁 Closing browser...')
-  await browser.close()
-  process.exit(0)
+let browser
+
+// TODO: On Windows, there is a long pause between the browser closing and "Closing browser..."
+// getting logged. Somehow CTRL+C stops Puppeteer browser before this function runs.
+// And why is there such a long pause?
+const shutDown = async (code = 0) => {
+  if (browser) {
+    logger.log('🏁 Closing browser...')
+    await browser.close() // TODO: Node doesn't seem to wait for this.
+    console.log('why doesn\'t this show up?')
+  }
+  process.exit(code)
 }
 
+process.on('SIGINT', shutDown)
+process.on('SIGQUIT', shutDown)
+process.on('SIGTERM', shutDown)
+
+process.on('exit', () => {
+  // TODO: Inspect the `code` parameter and log accordingly
+  logger.log('👋 Shutdown completed! Bye bye!')
+})
+
 // Here's where the app begins 🚀
-(async () => {
+const start = async () => {
   logger.log('🚦 Launching browser...')
   const { height, width } = BROWSER_SIZE
-  const browser = await puppeteer.launch({
+  browser = await puppeteer.launch({
     headless: HIDE_BROWSER,
     defaultViewport: { width, height },
     args: [`--window-size=${width},${height}`]
   })
 
-  process.on('SIGINT', () => shutDown(browser))
-  process.on('SIGQUIT', () => shutDown(browser))
-  process.on('SIGTERM', () => shutDown(browser))
-
-  // TODO: Inspect the `code` parameter and log accordingly
-  process.on('exit', () => {
-    logger.log('👋 Shutdown completed! Bye bye!')
-  });
-
   try {
     startChecking(browser)
   } catch (err) {
-    logger.error('💥 Loop failure:', err)
-    await shutDown()
-    process.exit(1)
+    logger.error('💥 App failure:', err)
+    await shutDown(1)
   }
-})();
+}
+
+start()

src/utils/wait.js

@@ -0,0 +1,3 @@
+const wait = duration => new Promise(resolve => setTimeout(resolve, duration))
+
+export default wait