feat: use serverless-chrome binary (#31)

* feat: use serverless-chrome binary
* chore: allow to set url for test function
* chore: log more result info for test function

Author: baocancode

README.md

@@ -1,7 +1,9 @@
 # joytocode/lighthouse-lambda
+
 Run [Google Chrome Lighthouse](https://github.com/GoogleChrome/lighthouse) on [AWS Lambda](https://aws.amazon.com/lambda/).
 
 ## Versions
+
 Since version 2.x, `lighthouse-lambda` has the same major version of [lighthouse](https://www.npmjs.com/package/lighthouse). For example, `lighthouse-lambda` 3.x will use `lighthouse` 3.x.
 
 This README is for version 3.x. To see older versions, visit:
@@ -14,8 +16,6 @@ This README is for version 3.x. To see older versions, visit:
 $ npm install lighthouse-lambda --save
 ```
 
-The postinstall script of `lighthouse-lambda` will download a Headless Chrome binary if it does not already exist. The binary is from [joytocode/headless-chrome-builder](https://github.com/joytocode/headless-chrome-builder) and is tested to make sure it works with Lighthouse.
-
 ## Lambda function
 
 ```js
@@ -60,7 +60,7 @@ $ docker run --rm -v "$PWD":/var/task lambci/lambda:build-nodejs8.10 bash -c "rm
 $ docker run --rm -v "$PWD":/var/task lambci/lambda:build-nodejs8.10 bash -c "rm -f *.zip && zip lambda.zip -r node_modules index.js package.json"
 ```
 
-- The file will be big (at least 80MB), so you need to upload it to S3 then deploy to Lambda from S3.
+- The file will be big (at least 75MB), so you need to upload it to S3 then deploy to Lambda from S3.
 - You should allocate at least 512 MB memory and 15 seconds timeout to the function.
 
 ## API
@@ -71,10 +71,14 @@ Same parameters as [Using Lighthouse programmatically](https://github.com/Google
 
 Returns a `Promise` of an Object with the following fields:
 
-- `chrome`: an instance of [`chromeLauncher.launch()`](https://github.com/GoogleChrome/chrome-launcher#launchopts).
+- `chrome`: an instance of [`chromeLauncher.launch()`](https://github.com/GoogleChrome/chrome-launcher#launchopts), remember to call `chrome.kill()` in the end.
 - `log`: an instance of [lighthouse-logger](https://github.com/GoogleChrome/lighthouse/tree/master/lighthouse-logger) (only if you set `options.logLevel`).
 - `start()`: a function to start the scan which returns a `Promise` of Lighthouse results.
 
+## Credits
+
+`lighthouse-lambda` uses the Headless Chrome binary (stable version) from [@serverless-chrome/lambda](https://www.npmjs.com/package/@serverless-chrome/lambda).
+
 ## License
 
 [MIT](LICENSE)

lib/checksum.js

@@ -1,16 +1,24 @@
-const path = require('path')
+const chromePath = require.resolve('@serverless-chrome/lambda/dist/headless-chromium')
 const chromeLauncher = require('chrome-launcher')
 const lighthouse = require('lighthouse')
-const chromeConfig = require('./chromeConfig')
+
+const defaultFlags = [
+  '--headless',
+  '--disable-dev-shm-usage',
+  '--disable-gpu',
+  '--no-zygote',
+  '--no-sandbox',
+  '--single-process',
+  '--hide-scrollbars'
+]
 
 module.exports = function createLighthouse (url, options = {}, config) {
   options.output = options.output || 'html'
   const log = options.logLevel ? require('lighthouse-logger') : null
   if (log) {
     log.setLevel(options.logLevel)
   }
-  const chromeFlags = chromeConfig.flags.concat(options.chromeFlags || [])
-  const chromePath = path.join(chromeConfig.binary.binPath, chromeConfig.binary.fileName)
+  const chromeFlags = options.chromeFlags || defaultFlags
   return chromeLauncher.launch({ chromeFlags, chromePath })
     .then((chrome) => {
       options.port = chrome.port