npm package: @jahed/firebase-rules
Description: A type-safe Firebase Real-time Database Security Rules builder.
Author: Jahed Ahmed
Latest version: 2.1.1

# @jahed/firebase-rules

[![npm](https://img.shields.io/npm/v/@jahed/firebase-rules.svg)](https://www.npmjs.com/package/@jahed/firebase-rules)
[![author](https://img.shields.io/badge/author-jahed-%23007fff)](https://jahed.dev/)

A type-safe Firebase Real-time Database Security Rules builder.

- Compose and re-use common rules.
- Reference constants used throughout the project.
- Catch any errors and typos.
- Auto-completion.

## Installation

```bash
npm install --save-dev @jahed/firebase-rules
```

## Usage

Import the modules you need to build your rules. You can create helper functions
to reduce reptition and give your rules more context. For this example, we'll
just use the modules directly to keep it simple.

```typescript
import {
  node,
  props,
  validate,
  newData,
  read,
  write,
  equal,
  auth,
  allowAll,
  param,
  between,
  oneOf,
  not,
  data,
} from "@jahed/firebase-rules";

const rules = {
  rules: node(
    props({
      app: node(
        props({
          update: node(
            props({
              version: node(validate(newData.isString())),
              force: node(validate(newData.isBoolean())),
              timestamp: node(validate(newData.isNumber())),
            }),
          ),
          delay: node(validate(newData.isNumber())),
        }),
        read(allowAll),
        write(equal(auth.uid, "service-admin")),
      ),
      users: node(
        param("$userId", ($userId) =>
          node(
            props({
              name: node(
                validate(newData.isString((val) => between(val.length, 0, 24))),
              ),
              created_at: node(
                validate(
                  newData.isNumber((newVal) =>
                    oneOf(
                      not(data.exists()),
                      data.isNumber((val) => equal(val, newVal)),
                    ),
                  ),
                ),
              ),
            }),
            write(equal($userId, auth.uid)),
            validate(newData.hasChildren(["name", "created_at"])),
          ),
        ),
        read(allowAll),
      ),
    }),
  ),
};

const json = JSON.stringify(rules, null, 2);
```

Now you can write `json` to a file and push it to Firebase. The configuration
above will look like this in JSON:

```json
{
  "rules": {
    "app": {
      "update": {
        "version": {
          ".validate": "newData.isString()"
        },
        "force": {
          ".validate": "newData.isBoolean()"
        },
        "timestamp": {
          ".validate": "newData.isNumber()"
        },
        "$other": {
          ".validate": false
        }
      },
      "delay": {
        ".validate": "newData.isNumber()"
      },
      "$other": {
        ".validate": false
      },
      ".read": true,
      ".write": "(auth.uid === \"service-admin\")"
    },
    "users": {
      "$userId": {
        "name": {
          ".validate": "(newData.isString() && ((newData.val().length > 0) && (newData.val().length < 24)))"
        },
        "created_at": {
          ".validate": "(newData.isNumber() && (!data.exists() || (data.isNumber() && (data.val() === newData.val()))))"
        },
        "$other": {
          ".validate": false
        },
        ".write": "($userId === auth.uid)",
        ".validate": "newData.hasChildren([\"name\",\"created_at\"])"
      },
      ".read": true
    },
    "$other": {
      ".validate": false
    }
  }
}
```

For more thorough examples, see [the tests](tests/database.rules.ts).

## API

For complete API documentation, [see the documentation website](https://jahed.github.io/firebase-rules/).

## License

[MIT](LICENSE).