object-generator
High-performance, customizable dummy object generator for testing and benchmarking.
Features
Guaranteed Structure Consistency
ThenestedSize
anddepth
options are always respected, ensuring consistent object structures even when circular references are enabled withcircular: true
. This guarantees predictable output regardless of configuration.Globally Unique Identifiers
WithglobalIndex: 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:
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
import { objectGenerator } from '@observ33r/object-generator';
const obj = objectGenerator({ size: 4 });
console.log(obj);
{
'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
import { objectGenerator } from '@observ33r/object-generator';
const obj = objectGenerator({
prefix: 'data',
size: 4,
nestedSize: 4,
depth: 1,
valueTypes: [String, Number, Boolean]
});
console.log(obj);
{
'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
import { objectGenerator } from '@observ33r/object-generator';
const arr = objectGenerator({
type: Array,
size: 8,
valueTypes: [Number],
});
console.log(arr);
[
0, 1, 2, 3,
4, 5, 6, 7
]
Generate a repeatable shuffled Typed Array
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));
Uint8Array(8) [
2, 0, 4, 1,
3, 6, 7, 5
]
ArrayBuffer {
[Uint8Contents]: <02 00 04 01 03 06 07 05>,
byteLength: 8
}
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
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);
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 to generate clean and optimized ESM builds.
To build package from source code, run:
npm run build
Testing
All tests are written in Vitest with native ESM support and zero transform overhead.
You can run the full suite with:
npm test
Contributing
Feel free to open issues or submit pull requests on GitHub.
License
This project is licensed under the MIT License.