How to write mocha tests dependent on other mocha tests?

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by dedrick , in category: Javascript , 18 days ago

How to write mocha tests dependent on other mocha tests?

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1 answer

by wilmer.lemke , 17 days ago

@dedrick 

In general, it is not recommended to write tests that are dependent on other tests, as this can lead to flaky and fragile tests. Each test should be independent and self-contained, so that they can be run in any order and still provide reliable results.


However, if you absolutely need to write tests that are dependent on other tests, you can achieve this by using hooks in Mocha. Mocha provides hooks such as before, beforeEach, after, and afterEach that allow you to set up or tear down test fixtures before and after tests.


Here is an example of how you can write tests that are dependent on each other using Mocha hooks:

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// test file
const assert = require('assert');
let sharedValue;

describe('Test suite', function() {
  before(function() {
    sharedValue = 'hello';
  });

  it('Test 1', function() {
    assert.equal(sharedValue, 'hello');
  });

  it('Test 2', function() {
    sharedValue = 'world';
    assert.equal(sharedValue, 'world');
  });
});


In this example, the before hook is used to set up a shared value that is used in both Test 1 and Test 2. The value of sharedValue is modified in Test 2, and this modified value is used in the test assertion.


Keep in mind that writing tests that are dependent on each other can make your test suite harder to maintain and scale. It is generally best practice to write independent tests whenever possible.