Decorators library for writing jest-based tests

Wrapper around jest JavaScript testing framework.

Provides decorators with core jest globals. Also, provides utilities to minimize boilerplate code and make tests code more consistent.

Read documentation.

Jest test:

describe("MyFnSpec", () => {
    
    const consoleLogSpy = jest.spyOn(console, "log");
    
    afterEach(() => {
        consoleLogSpy.mockClear();
    });
    
    afterAll(() => {
        consoleLogSpy.mockRestore();
    });
    
    test("shouldCallLogTwice", () => {
        myFn("foo");
        expect(consoleLogSpy).toHaveBeenCalledTimes(2);
    });
    
    test("shouldCallLogOnce", () => {
        myFn("bar");
        expect(consoleLogSpy).toHaveBeenCalledTimes(1);
    });
});

Same test with @jest-decorated:

@Describe()
class MyFnSpec {
    
    @Spy(console, "log")
    consoleLogSpy;
    
    @Test()
    shouldCallLogTwice() {
        myFn("foo");
        expect(this.consoleLogSpy).toHaveBeenCalledTimes(2);
    }
    
    @Test()
    shouldCallLogOnce() {
        myFn("bar");
        expect(this.consoleLogSpy).toHaveBeenCalledTimes(1);
    }
}

Install

Does not bring jest as a dependency, you should install the wanted version by yourself.

Install jest

npm i -D jest

Install @jest-decorated

npm i -D @jest-decorated/core

Install extensions (if needed)

npm i -D @jest-decorated/react

Setup

With setupFilesAfterEnv jest option

You can register decorators once and use them everywhere, without importing! To achieve that, add globals files to setupFilesAfterEnv jest config.

For example, if we want to register core and react decorators globally:

{
  "setupFilesAfterEnv": [
    "@jest-decorated/core/globals",
    "@jest-decorated/react/globals"
  ]
}

Or, if you already have single entry point for tests setup:

{
  "setupFilesAfterEnv": [
    "<rootDir>/testSetup.ts"
  ]
}

// testSetup.ts

import "@jest-decorated/core/globals";
import "@jest-decorated/react/globals";

With importing globals file

Another option is to import globals files in each test separately:

// myFn.spec.ts

import "@jest-decorated/core/globals";
import "@jest-decorated/react/globals";

@Describe()
@RunWith(ReactTestRunner)
class MyFnSpec {
  // ...
}

With direct import

If solutions above doesn't serves your needs, you can use direct import:

// myFn.spec.ts

import { Describe, RunWith } from "@jest-decorated/core";
import { ReactTestRunner } from "@jest-decorated/react";

@Describe()
@RunWith(ReactTestRunner)
class MyFnSpec {
  // ...
}

TypeScript

When using with TypeScript, make sure your setup file (in setupFilesAfterEnv section) is a .ts and not a .js to include the necessary types.

You will also need to include your setup file and the test folder in your tsconfig.json if you haven't already:

{
  "include": [
    "./testSetup.ts",
    "./__tests__"
  ]
}

Extensions

Support for different libs and frameworks. Currently, only React is strongly supported.

Decorators

Read docs.

Contributing

Contribution guidelines for this project

License

MIT License