npm package: @observ33r/object-generator
Description: High-performance, customizable dummy object generator for testing and benchmarking.
Author: David Čuček
Latest version: 1.0.3

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# object-generator

High-performance, customizable dummy object generator for testing and benchmarking.

## Features

- **Guaranteed Structure Consistency**  
  The `nestedSize` and `depth` options are always respected, ensuring consistent object structures even when circular references are enabled with `circular: true`. This guarantees predictable output regardless of configuration.

- **Globally Unique Identifiers**  
  With `globalIndex: true`, all keys and string values remain unique across the generated object. This uniqueness eliminates ambiguity and ensures reliable comparisons or traversals.

- **Real-World Object Design**  
  Objects are crafted to mimic real-world data structures as closely as possible. This approach avoids overly simplistic or uniform patterns that could trigger JIT (Just-In-Time) compiler optimizations, making the generator ideal for robust benchmarking and testing scenarios.

- **Performance Testing Ready**  
  Designed for benchmark challenges between libraries by providing diverse and repeatable complex objects!

- **Type-Safe**  
  Fully typed with TypeScript declarations.

## Installation

Install the package via npm:

```bash
npm install @observ33r/object-generator
```

## Usage

### `objectGenerator([options])`

- **options**: Optional configuration object (see below).
- **Returns**: An object of the specified type with generated content based on the provided options.

#### Options

| Property | Type | Default | Description |
| :---: | :---: | :---: | :--- |
| prefix | `string \| number \| false` | `false`| A prefix to prepend to generated keys/strings. Must be a non-empty string, number or `false`. |
| type | `constructor` | `Object` | The type of object to generate. Must be one of `Object`, `Array`, `Set`, `Map`, or `Uint8Array`. |
| size | `number` | `16` | Size of the top-level object. Must be an integer. |
| nestedSize | `number` | `16` | Size of nested objects. Must be an integer. |
| depth | `number` | `0` | Maximum depth for nested structures. Must be an integer.|
| valueTypes | `[constructor \| NaN \| undefined \| null]` | `[String]` | Array of value types to include: `Boolean`, `Number`, `String`, `Date`, `RegExp`, `Uint8Array`, `Object`, `Array`, `Set`, `Map`, `NaN`, `undefined`, `null`. |
| globalIndex | `boolean` | `true` | Whether to include a global index in generated keys/values. |
| circular | `boolean` | `false` | Whether to allow circular references in the generated object. |
| shuffle | `boolean` | `false` | Whether to shuffle the order of elements or keys. |
| seed | `number` | *random* | Seed for randomization when `shuffle` is enabled. If not provided, a random seed is used. |

## Examples

#### Generate a simple Object
 
```javascript
import { objectGenerator } from '@observ33r/object-generator';

const obj = objectGenerator({ size: 4 });

console.log(obj);
```
```console
{
  'string-4-0': 'value-4-0',
  'string-4-1': 'value-4-1',
  'string-4-2': 'value-4-2',
  'string-4-3': 'value-4-3'
}
```

#### Generate a nested Object with a prefix
 
```javascript
import { objectGenerator } from '@observ33r/object-generator';

const obj = objectGenerator({
  prefix: 'data',
  size: 4,
  nestedSize: 4,
  depth: 1,
  valueTypes: [String, Number, Boolean]
});

console.log(obj);
```
```console
{
  'data-string-4-0-0-0': 'data-value-4-0-0-0',
  'data-number-4-0-1-1': 1,
  'data-boolean-4-0-2-2': true,
  'data-object-4-0-3-3': {
    'data-string-4-1-4-0': 'data-value-4-1-4-0',
    'data-number-4-1-5-1': 1,
    'data-boolean-4-1-6-2': true,
    'data-string-4-1-7-3': 'data-value-4-1-7-3'
  }
}
```

#### Generate a simple numeric Array


```javascript
import { objectGenerator } from '@observ33r/object-generator';

const arr = objectGenerator({
  type: Array,
  size: 8,
  valueTypes: [Number],
});

console.log(arr);
```
```console
[
  0, 1, 2, 3,
  4, 5, 6, 7
]
```

#### Generate a repeatable shuffled Typed Array

```javascript
import { objectGenerator } from '@observ33r/object-generator';

const typedArray = objectGenerator({
  type: Uint8Array,
  size: 8,
  shuffle: true,
  seed: 42
});

//Uint8Array
console.log(typedArray);
//or ArrayBuffer
console.log(typedArray.buffer);
//or DataView
console.log(new DataView(typedArray.buffer));
```
```console
Uint8Array(8) [
  2, 0, 4, 1,
  3, 6, 7, 5
]
```
```console
ArrayBuffer {
  [Uint8Contents]: <02 00 04 01 03 06 07 05>,
  byteLength: 8
}
```
```console
DataView {
  byteLength: 8,
  byteOffset: 0,
  buffer: ArrayBuffer {
    [Uint8Contents]: <02 00 04 01 03 06 07 05>,
    byteLength: 8
  }
}
```

#### Generate a repeatable shuffled nested Set without a global index

```javascript
import { objectGenerator } from '@observ33r/object-generator';

const set = objectGenerator({
  type: Set,
  size: 2,
  nestedSize: 2,
  depth: 2,
  valueTypes: [Set],
  globalIndex: false,
  shuffle: true,
  seed: 42
});

console.log(set);
```
```console
Set(2) {
  Set(2) {
    Set(2) { 'value-2-2-1', 'value-2-2-0' },
    Set(2) { 'value-2-2-0', 'value-2-2-1' }
  },
  Set(2) {
    Set(2) { 'value-2-2-0', 'value-2-2-1' },
    Set(2) { 'value-2-2-1', 'value-2-2-0' }
  }
}
```

## Build

This package uses [rollup](https://rollupjs.org/) to generate clean and optimized ESM builds. 

To build package from source code, run:

```bash
npm run build
```

## Testing

All tests are written in [Vitest](https://vitest.dev) with native ESM support and zero transform overhead.

You can run the full suite with:

```bash
npm test
```

## Contributing

Feel free to open issues or submit pull requests on [GitHub](https://github.com/observ33r/object-generator).

## License

This project is licensed under the [MIT License](LICENSE).