# Node Redis: Examples

This folder contains example scripts showing how to use Node Redis in different scenarios.

| File Name                   | Description                                                                                                                                         |
|-----------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------|
| `blocking-list-pop.js`      | Block until an element is pushed to a list                                                                                                          |
| `bloom-filter.js`           | Space efficient set membership checks with a [Bloom Filter](https://en.wikipedia.org/wiki/Bloom_filter) using [RedisBloom](https://redisbloom.io)   |
| `command-with-modifiers.js` | Define a script that allows to run a command with several modifiers                                                                                 |
| `connect-as-acl-user.js`    | Connect to Redis 6 using an ACL user                                                                                                                |
| `count-min-sketch.js`       | Estimate the frequency of a given event using the [RedisBloom](https://redisbloom.io) Count-Min Sketch                                              |
| `cuckoo-filter.js`          | Space efficient set membership checks with a [Cuckoo Filter](https://en.wikipedia.org/wiki/Cuckoo_filter) using [RedisBloom](https://redisbloom.io) |
| `lua-multi-incr.js`         | Define a custom lua script that allows you to perform INCRBY on multiple keys                                                                       |
| `managing-json.js`          | Store, retrieve and manipulate JSON data atomically with [RedisJSON](https://redisjson.io/)                                                         |
| `search-hashes.js`          | Uses [RediSearch](https://redisearch.io) to index and search data in hashes                                                                         |
| `search-json.js`            | Uses [RediSearch](https://redisearch.io/) and [RedisJSON](https://redisjson.io/) to index and search JSON data                                      |
| `set-scan.js`               | An example script that shows how to use the SSCAN iterator functionality                                                                            |
| `stream-producer.js`        | Adds entries to a [Redis Stream](https://redis.io/topics/streams-intro) using the `XADD` command                                                    |
| `stream-consumer.js`        | Reads entries from a [Redis Stream](https://redis.io/topics/streams-intro) using the blocking `XREAD` command                                       |
| `time-series.js`            | Create, populate and query timeseries data with [Redis Timeseries](https://redistimeseries.io)                                                      |
| `topk.js`                   | Use the [RedisBloom](https://redisbloom.io) TopK to track the most frequently seen items.                                                           |
| `stream-consumer-group.js`  | Reads entties from a [Redis Stream](https://redis.io/topics/streams-intro) as part of a consumer group using the blocking `XREADGROUP` command      |

## Contributing

We'd love to see more examples here. If you have an idea that you'd like to see included here, submit a Pull Request and we'll be sure to review it!  Don't forget to check out our [contributing guide](../CONTRIBUTING.md).

## Setup

To set up the examples folder so that you can run an example / develop one of your own:

```
$ git clone https://github.com/redis/node-redis.git
$ cd node-redis
$ npm install -ws && npm run build-all
$ cd examples
$ npm install
```

### Coding Guidelines for Examples

When adding a new example, please follow these guidelines:

* Add your code in a single JavaScript or TypeScript file per example, directly in the `examples` folder
* Do not introduce other dependencies in your example
* Give your `.js` file a meaningful name using `-` separators e.g. `adding-to-a-stream.js` / `adding-to-a-stream.ts`
* Indent your code using 2 spaces
* Use the single line `//` comment style and comment your code
* Add a comment at the top of your `.js` / `.ts` file describing what your example does
* Add a comment at the top of your `.js` / `.ts` file describing any Redis commands that need to be run to set up data for your example (try and keep this minimal)
* Use semicolons
* Use `async` and `await`
* Use single quotes, `'hello'` not `"hello"`
* Place your example code in a single `async` function where possible, named according to the file name e.g. `add-to-stream.js` would contain `const addtoStream = async () => { ... };`, and call this function at the end of the file e.g. `addToStream();`
* Unless your example requires a connection string, assume Redis is on the default localhost port 6379 with no password
* Use meaningful example data, let's not use `foo`, `bar`, `baz` etc!
* Leave an empty line at the end of your `.js` file
* Update this `README.md` file to add your example to the table

Use [connect-as-acl-user.js](./connect-as-acl-user.js) as a guide to develop a well formatted example script.

### Example Template

Here's a starter template for adding a new example, imagine this is stored in `do-something.js`:

```javascript
// This comment should describe what the example does
// and can extend to multiple lines.

// Set up the data in redis-cli using these commands:
//   <add your command(s) here, one per line>

import { createClient } from 'redis';

async function doSomething() {
    const client = createClient();

    await client.connect();

    // Add your example code here...

    await client.quit();
}

doSomething();
```