polyfill-lambda

Uses polyfill.io's service to generate a polyfill based on the user agent of the request. Aggressively caches to ensure as few requests as possible.

Getting started

Ensure you have node and yarn installed. Run yarn start to start a local server at http://localhost:8080. Visit that location in different browsers to view the polyfill. Note that since this server is running in development, it returns unminified JavaScript.

Deployment

Install serverless by running npm install -g serverless. You can then run sls deploy --aws-profile [PROFILE] to deploy the function. This will trigger output that looks something like:

Serverless: Packaging service...
Serverless: Excluding development dependencies...
Serverless: Uploading CloudFormation file to S3...
Serverless: Uploading artifacts...
Serverless: Uploading service .zip file to S3 (57.17 MB)...
Serverless: Validating template...
Serverless: Updating Stack...
Serverless: Checking Stack update progress...
..............
Serverless: Stack update finished...
Service Information
service: polyfill
stage: production
region: us-west-2
stack: polyfill-production
api keys:
  None
endpoints:
  GET - https://xxxxxxxxxx.execute-api.us-west-2.amazonaws.com/production/polyfill
functions:
  polyfill: polyfill-production-polyfill

You can then place that URL in a script tag in your application's HTML before you load your main JavaScript to get all of the necessary polyfills.

Testing

Unit tests are run by executing yarn test.