# Accumulate Implement the `accumulate` operation, which, given a collection and an operation to perform on each element of the collection, returns a new collection containing the result of applying that operation to each element of the input collection. Given the collection of numbers: - 1, 2, 3, 4, 5 And the operation: - square a number (`x => x * x`) Your code should be able to produce the collection of squares: - 1, 4, 9, 16, 25 Check out the test suite to see the expected function signature. ## Restrictions Keep your hands off that collect/map/fmap/whatchamacallit functionality provided by your standard library! Solve this one yourself using other basic tools instead. ## Setup Go through the setup instructions for TypeScript to install the necessary dependencies: http://exercism.io/languages/typescript ## Requirements Install assignment dependencies: ```bash $ yarn install ``` ## Making the test suite pass Execute the tests with: ```bash $ yarn test ``` ## Source Conversation with James Edward Gray II [https://twitter.com/jeg2](https://twitter.com/jeg2) ## Submitting Incomplete Solutions It's possible to submit an incomplete solution so you can see how others have completed the exercise.