next-shared-cache

This project provides a shared cache implementation for Next.js applications using remote server with in-memory TTL cache or Redis as the cache store.

Developing

To get started with development, install the project dependencies using npm ci. Then, run npm run dev to start the development server and watch for changes to the handler and server modules:

npm ci
npm run build
npm run dev

In a separate terminal, run the cache-testing app using npm run build:app and npm run start:app. Note that you need to rebuild the cache-testing app every time the handler module is rebuilt:

npm run build:app
npm run start:app

Remember that you need to rebuild cache-testing every time handler rebuild is happening.

Using Redis

To use Redis as the cache store, you can use Docker to start a Redis instance with the following command:

docker run -d --name redis-stack -p 6379:6379 -p 8001:8001 redis/redis-stack:latest

Then, create a .env.local file inside the apps/cache-testing directory and add the REDIS_URL environment variable:

REDIS_URL=redis://localhost:6379

Finally, use the handler-redis module in next.config.js to configure the cache handler. The isrFlushToDisk field is required and should be set to false:

const nextConfig = {
    experimental: {
        incrementalCacheHandlerPath: require.resolve('./cache-handler-redis'),
        isrFlushToDisk: false,
    },
};

Then, run the following commands to start the development server and the cache-testing app:

npm run dev:redis
npm run build:app
npm run start:app

Contributing

Before committing changes, run the linting and formatting jobs using npm run lint and npm run format.

npm run lint
npm run format

Caveats

In-memory cache in dev mode

When you run npm run dev the server package is in watch mode. So it drops in-memory cache every time you make a change in sources.

Troubleshooting

If you are using VS Code and see a Parsing error: Cannot find module 'next/babel' error in .js files, create a .vscode/settings.json file in the root of the project and add the following configuration:

{
    "eslint.workingDirectories": [{ "pattern": "apps/*/" }, { "pattern": "packages/*/" }, { "pattern": "utils/*/" }]
}