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NodeJS singleton bug 2

  • Language JavaScript
Trivial check of singleton pattern knowledge

NodeJS Singleton bug


We have a date wrapper to get the current date. Normally it should always return the current date but when artificial date is set then that date should always be returned. This is very useful for unit testing. We are instantiating this wrapper in many places of the application, but what we want is that the artifical date should be kept throughout all the instances, no matter how many times it is instantiated.


Right now, whenever we instantiate the wrapper the artificial date is lost. Please find the bug and fix the implementation so that the following tests pass:

when dateWrapper is instantiated
    it should return the current date
  and artificial date is set
      it should return the same date despite the running time
  and another dateWrapper is instantiated
      it should return the same date despite the running time


To install dependencies from package.json:

npm install

To run tests in development mode:

mocha --watch

To run jshint and tests:

npm test

To run jshint and tests with human readable output:

grunt --force

Start this test

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