@brunoss/mock-builder
Version:
Mock Builder for FakerJS and Vitest
130 lines (101 loc) • 4.88 kB
Markdown
[](https://github.com/brunossantana/mock-builder/actions)
[](https://github.com/brunossantana/mock-builder/blob/main/LICENSE)
[](https://www.npmjs.com/package/@brunoss/mock-builder)
[](https://www.npmjs.com/package/@brunoss/mock-builder)
[](https://jsr.io/@brunossantana/mock-builder)
[](https://bundlephobia.com/result?p=@brunoss/mock-builder)
[](https://bundlephobia.com/result?p=@brunoss/mock-builder)
[](https://github.com/brunossantana/mock-builder/pulse)
[](https://github.com/brunossantana/mock-builder/commits/main)
[](https://codecov.io/github/brunossantana/mock-builder)
The `mock-builder` is a TypeScript library designed to help you create objects based on a specified shape. Each property in the shape can be either a static value or a function that returns a value. The library emphasizes immutability, ensuring that each modification creates a new instance, thereby avoiding side effects and promoting predictable, maintainable code.
- **Immutable Design**: Ensures that every operation returns a new instance, avoiding unintended side effects.
- **Flexible Shape Definition**: Supports both static values and functions that generate values.
- **TypeScript Support**: Fully typed for a robust development experience.
- **Chainable API**: Easily chain methods for building complex objects.
Install the package via npm:
```bash
npm i -D @brunoss/mock-builder
```
```ts
import { Builder } from 'immutable-builder';
// Define a shape for the object
const builder = new Builder({
id: () => Math.floor(Math.random() * 100),
name: 'defaultName'
});
// Build the object
const myObject = builder.build();
console.log(myObject);
// Output: { id: 42, name: 'defaultName' }
```
```ts
const builder = new Builder({
id: 1,
name: 'Alice'
});
// Apply default values
const updatedBuilder = builder.applyDefaultValues({
age: () => 30, // Function executed during build
isActive: true
});
const myObject = updatedBuilder.build();
console.log(myObject);
// Output: { id: 1, name: 'Alice', age: 30, isActive: true }
```
```ts
const builder = new Builder({
id: 1,
name: 'Alice'
});
// Set values based on a condition
const updatedBuilder = builder.setConditionalValue(
'isAdmin',
userType === 'admin',
true,
false
);
const myObject = updatedBuilder.build();
console.log(myObject);
// Output: { id: 1, name: 'Alice', isAdmin: false }
```
`Builder`
`constructor(shape: Shape<T>)`
- Creates a new Builder instance.
- Parameters:
- shape: An object where each key is a property of the resulting object and can be either a value or a function that returns a value.
`build(): T`
- Constructs an object based on the shape provided during instantiation.
- Returns: An object of type T with all values resolved.
`withValue<K extends keyof T>(prop: K, value: T[K]): Builder<T>`
- Sets a specific property of the shape to always return a given value.
- Parameters:
- prop: The property name to set.
- value: The value that the property should always return.
- Returns: A new Builder instance.
`setConditionalValue<K extends keyof T>(prop: K, condition: boolean, trueValue: T[K], falseValue: T[K]): Builder<T>`
- Sets a property based on a condition.
- Parameters:
- prop: The property name to set.
- condition: The condition to evaluate.
- trueValue: The value if the condition is true.
- falseValue: The value if the condition is false.
- Returns: A new Builder instance.
`applyDefaultValues(defaults: Partial<Shape<T>>): Builder<T>`
- Applies default values to undefined properties. If a default value is a function, it runs during build() to get the final value.
- Parameters:
- defaults: An object containing default values for properties.
- Returns: A new Builder instance.
## Contributing
Contributions are welcome! Please feel free to submit a Pull Request or open an Issue on GitHub.
## Credits
based on [fluentbuilder](https://github.com/lucasteles/fluentbuilder)