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javascriptunit-testingtestingrequire

Javascript require() a file in tests several times does not create the object again

I am writing some tests for a javascript API with mocha. I docker up my project before running the tests and I have realized that requiring a file to create an object in several tests, for example like these ones: 

    it('should return false 1', () =>  {
      const testObject = require(./file.json)
      delete testObject.neededAttribute1;
      expect(function(testObject)).to.be.false;
    });

    it('should return false 2', () =>  {
      const testObject = require(./file.json)
      delete testObject.neededAttribute2;
      expect(function(testObject)).to.be.false;
    });

Javascript won't create the object testObject in the second test, but use the first one with the changes previously made, making my tests unusable if I don't manually restore the object with whatever I have changed after the test has been executed.

I understand Javascript does this to be more efficient not loading the same file all the time, but just once.

But how can I make my tests in which I have a file with a correct object and I want to introduce small modifications one by one in each test?

Any ideas?

Solution

  • clone the object.

    Import your object in a before function

    https://futurestud.io/tutorials/mocha-global-setup-and-teardown-before-after

    Then in each function or in beforeEach function, clone that object with something like lodash's cloneDeep function.

    https://lodash.com/docs/4.17.15#cloneDeep