ts-randomizer

A tool to create random data by type parameters

Usage no npm install needed!

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README

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Typescript Randomizer

A tool to create random data by requested types. It's designed to minimize the arrange phase of unit tests to maximize maintainability, making it easier to create objects containing random test data. So now we don't need for hand-coding anonymous variables as part of a test's arrange phase.

Randomizer can help by creating variables with random data. Here's a simple example:

// types
class Entity {
  id: string;
  name: string;
}

interface Response<T> {
  data: T;
}

// test
it('some test', () => {
  const response = Randomizer.create<Response<Entity>>();

  // someClass returns the response data
  const result = someClass.getEntityResult(response);

  expect(result.id).toBe(response.entity.id)
});

Description

Typescript Randomizer includes two parts:

  • Typescript transformer to generate a description for requested types.
  • Randomizer class with methods to create random data according to generated description.

How to install

Randomizer doesn't work without the typescript transformer. The transformer needs to be provided at compile time. There are many different ways to do it. Please read the following guide to find your configuration

Also, there are some ready examples:

Example usage

Create random data

const data = Randomizer.create<string>();

// "850eb858-f3b7-4d9c-9715-563a7fbd8f0d"

Create many random data

interface A {
    a: string;
}

const data = Randomizer.createMany<A>(2);

//
// [
//    { a: "dbb04326-3f0d-4eb1-8bec-2b22fef39f0b" },
//    { a: "3d48ee0b-2004-4745-8453-98b36d260fc4" },
// ]

Create random data with default values

interaface A {
    a: string;
}

const data = Randomizer.build<A>()
    .with(x => x.a = 'my string')
    .create();

// { a: "my string" }

Create data for types with type arguments

interface B<C, D> {
    c: C[],
    d: D;
}

class A<T> {
    a: B<T, boolean>
}

const data = Randomizer.create<A<string>>();

// {
//   "a":{
//      "c":[
//         "850eb858-f3b7-4d9c-9715-563a7fbd8f0d",
//         "dbb04326-3f0d-4eb1-8bec-2b22fef39f0b",
//         "10efb53e-a76f-4b34-83b5-b7cf9a913e46",
//         "3d48ee0b-2004-4745-8453-98b36d260fc4",
//         "11774a70-488c-48d5-bb80-b367ecd857ed"
//      ],
//      "d":true
//   }
// }

For more examples, take a look for tests folder

License

This project is licensed under the MIT License