react-automation-profiler

Analyze your React app's renders with automated user flows that generate comparison charts. Run flows before and after major changes to see how it effects components and renders, or run them on every build.

What Can You Do?

• Create user flows unique to the app that will automatically be run in the background
• Rerun automation flows every time the codebase is built during development, or rerun after x number of builds
• Compare charts that get generated as you work (or do a before-and-after by stashing major changes) to see if changes are creating more/less renders, reducing render timings, etc.
• Export all generated charts into a single HTML file
• TypeScript support
• Other Resources

Contents

• Try it out
• Install
• Wrapping Components With AutomationProfiler
• Automation Flows
• CLI: Generating Charts
• rap options

Try it out

To try react-automation-profiler out:

Clone the repo

git clone git@github.com:rpivo/react-automation-profiler.git

Start the example app

This will install all dependencies and start the example app.

npm run example

Start rap

In a separate terminal:

npm run rap

This will start react-automation-profiler, which will run the automation flows inside example/react.automation.yaml and then generate render charts. These charts should automatically open in your browser once automation is complete.

Install

npm i -D react-automation-profiler

or

yarn add react-automation-profiler --dev

Wrapping Components With AutomationProfiler

To profile specific component trees, import the AutomationProfiler component from react-automation-profiler. AutomationProfiler can wrap any component that you want to profile, similarly to how React's Profiler API works. It needs only one prop: id: string. Try to make the id short. This will help with readability on charts that display many renders.

You can wrap your whole application in your index file:

import React from 'react';
import { render } from 'react-dom';
import App from 'components/App';
import { AutomationProfiler } from 'react-automation-profiler';

render(
  <AutomationProfiler id="p-app">
    <App />
  </AutomationProfiler>,
  document.getElementById('root')
);

Or, you can wrap deeply nested components:

import React from 'react';

export default () => (
  <AutomationProfiler id="p-card">
    <DeeplyNestedComponent />
  </AutomationProfiler>
);

You can wrap as many components and at as many levels as you want. react-automation-profiler will track all of these components' renders and auto-generate charts based on render metrics of these components during specific user flows.

Automation Flows

You can define your automation flows in a YAML file at the root of your repo using the name react.automation.yml (or .yaml extension).

Here's an example react.automation.yml file:

Toggle PlayArea Card Active:
  - click div.playArea div.card
  - click div.playArea
Click Each PlayArea Card:
  - click div.playArea div.card:nth-of-type(1)
  - click div.playArea div.card:nth-of-type(2)
  - click div.playArea div.card:nth-of-type(3)
  - click div.playArea div.card:nth-of-type(4)
  - click div.playArea div.card:nth-of-type(5)
  - click div.playArea
Draw Card:
  - click div.stackedCard
  - click div.playArea

In the file above, there are three keys that each represent a different automation flow:

• Toggle PlayArea Card Active
• Click Each PlayArea Card
• Draw Card

In the example above, the first flow Toggle PlayArea Card Active has two actions: clicking the CSS selector div.playArea div.card, and then clicking the CSS selector div.playArea. This represents what a user would do when toggling a PlayArea Card's active state.

There are currently three action types that can be used in react.automation.yaml:

• click
• focus
• hover

Note that # marks the beginning of a comment in YAML, so the HTML tag should always prefix an isolated id:

- click button#cta

Note: The automation flows will run one after another in the order they are listed in the automation file. No subsequent page loads happen between each flow.

CLI: Generating Charts

There are a few prerequisites before you can start generating charts:

• AutomationProfiler must be wrapping at least one of your components.
• A react.automation.yaml file should be set up at the root of your repo.
• Your app should be running locally (ex: running at http://localhost:8000/index.html).

After that, you can then call the rap command in a separate terminal to start generating charts:

npx rap --page=http://localhost:8000/index.html --watch

rap options

option	type	required	default	description
page	string	yes		the page that automation will be run on.
averageOf	number	no	1	runs each automation flow n number of times and generates averaged metrics for the flow.
changeInterval	number	no	1	rerun after n number of changes. Note that there is a cooldown of 10 seconds before another change is counted. This flag effectively does nothing without use of the watch flag.
includeMount	boolean	no	false	includes the initial mount phase renders that happen before any automation flows are initialized.
port	number	no	1235	the port that charts will be displayed on.
watch	boolean or string	no	false	rerun rap on any changes to the given folder. If set as a boolean (ex: --watch), rerun on any changes inside the repo. If set as a string (ex: --watch=src), rerun on any changes in the given folder. This will save charts from the previous run(s) and generate new charts based on the latest changes, resulting in a new version for each flow. Note that watch runs on a 10-second delay to allow the application's local development toolchain to finish building before re-running the automation against the new build.

Programmatic usage example

  import { Automation } from 'react-automation-profiler/lib/api/index.js';


  async function myAppProfilingFn() {
    const results = await Automation.run({
      averageOf: 3,
      includeMount: false,
      page: 'http://my-app-host.com',
    });


    const postProcessedResults = someParsingFunction(results)
    externalService.send(postProcessedResults)
  }

If you would like to see the working example, please run:

  npm run example
  # in the second terminal
  node ./example/src/api.mjs

You still need to have react.automation.yaml defined in the directory where the script is executed.

Other Resources

Visit pptr.dev for the Puppeteer API.