# Compare Three Entities

A small utility library that compares three JavaScript objects and reports the differences between them.  
The comparison is deep, meaning nested objects are compared recursively. The result is an array of difference objects, each containing:

- `key`: The dot‑separated path to the differing property.
- `values`: An array of the values from the three objects in the order `[a, b, c]`.

## Installation

```bash
npm install compare-three-entities
```

## Usage

```js
const compare = require('compare-three-entities');

const a = { name: 'Alice', age: 30, address: { city: 'NY' } };
const b = { name: 'Alice', age: 31, address: { city: 'NY' } };
const c = { name: 'Alice', age: 30, address: { city: 'LA' } };

const differences = compare(a, b, c);
console.log(differences);
// [
//   { key: 'age', values: [30, 31, 30] },
//   { key: 'address.city', values: ['NY', 'NY', 'LA'] }
// ]
```

## API

### `compare(a, b, c)`

- **Parameters**:
  - `a` – First object.
  - `b` – Second object.
  - `c` – Third object.
- **Returns**: `Array` – Sorted array of difference objects.

## Testing

Run the test suite with:

```bash
npm test
```

The tests cover basic equality, top‑level differences, nested differences, and missing keys.

## License

MIT