Before developing, clone the repository and run yarn from the root of the repo to install all dependencies.
Most people should be able to get up and running just by running:
yarn startThis uses npm-run-all to run the functions dev server and app dev server concurrently.
Run the functions dev server
From inside the project folder, run:
yarn start:lambda
This will open a local server running at http://localhost:9000 serving your Lambda functions, updating as you make changes in the src/lambda folder.
You can then access your functions directly at http://localhost:9000/{function_name}, but to access them with the app, you'll need to start the app dev server. Under the hood, this uses react-scripts' advanced proxy feature with the setupProxy.js file.
Run the app dev server
While the functions server is still running, open a new terminal tab and run:
yarn start:app
This will start the normal create-react-app dev server and open your app at http://localhost:3000.
Local in-app requests to the relative path /.netlify/functions/* will automatically be proxied to the local functions dev server.
The service worker does not work with lambda functions out of the box. It prevents calling the function and returns the app itself instead (Read more). To solve this you have to eject and enhance the service worker configuration in the webpack config. Whitelist the path of your lambda function and you are good to go.