Как использовать Mocha.js для тестирования асинхронного кода?

Пользователь

от lilla.herman , в категории: JavaScript , 7 месяцев назад

Как использовать Mocha.js для тестирования асинхронного кода?

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1 ответ

Пользователь

от brenna , 7 месяцев назад

@lilla.herman 

Mocha provides several ways to test asynchronous code. Here's how you can use Mocha.js to test asynchronous code:

  1. Install Mocha.js globally or locally in your project using npm:
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npm install -g mocha


or

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npm install mocha --save-dev


  1. Create a test file (e.g., test.js) and require the necessary modules:
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const assert = require('assert');


  1. Write a test case using Mocha's it() function. Use the done callback to signal the completion of an asynchronous test:
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it('should do something asynchronously', (done) => {
  // Perform asynchronous actions (e.g., API request, reading a file)
  // Call the done() callback when the asynchronous action completes
});


  1. Inside the test case, you can make use of assertions from the assert module to verify the expected behavior of your code:
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it('should do something asynchronously', (done) => {
  setTimeout(() => {
    assert.strictEqual(1 + 1, 2); // Example assertion
    done(); // Call done() to signal the test completion
  }, 1000); // Simulate an asynchronous action
});


  1. Run the tests using the mocha command in your terminal:
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mocha test.js


Mocha handles asynchronous code by default. By using the done callback, Mocha knows to wait until the callback is called to complete the test.


You can also use Mocha's support for Promises and the async/await syntax for testing asynchronous code. Mocha will automatically handle the Promise resolution or async function, allowing you to write more readable and concise tests.