/json-transformer

Primary LanguageC#

Code Challenge Instructions

Write a program that transforms data.json into data-transformed.json. Have a look at example-output.json to show how the data should be transformed.

General Approach and Assumptions

  • Solution should be implemented in C#, Swift, or C++.
  • Read JSON data.json from current directory, convert data, write data-transformed.json to current directory.
  • Solution should build and run with a single CLI command or via opening a project in an IDE like Visual Studio or Xcode and selecting 'Run' or equivalent.
  • Thirdparty dependencies should be kept to a minimum and must be fetched and installed as a part of the build process.
  • Solution should write output file directly to project directory unless otherwise specified.

Criteria

Your work will be evaluated primarily on:

  • Consistency of coding style.
  • Idiomatic language use.
  • Use of asynchronous features if supported by your language of choice.
  • Correct and complete unit test coverage.
  • General quality of code and technical communication.

How to submit your work

  1. Fork this project on github.
  2. Update this README.md file with instructions on how to build/test/run your solution.
  3. When you're finished, send us the URL of your public repository.

Solution notes Eddy Pronk

Building

  • Install the .NET 5.0 SDK
  • Clone this repository and change into the repository root directory.
  • On the command line type dotnet publish -c Release -r win-x64
  • The resulting executable can be retrieved from Transform.App\bin\Release\net5.0\win-x64\Transform.App.exe

Testing

  • On the command line type dotnet test

Running

  • On the command line type Transform.App\bin\Release\net5.0\win-x64\Transform.App.exe

(A copy of the output of my solution is in the project directory with the name data-transformed-sample.json for convenience)

Implementation notes

The transformation splits up customers and orders in the output file. The simplest implementation would require the full set of Customer and OrderCollection objects to be kept in memory to write the output.

The memory usage would be proportional to the input file size. For very large files this could become an issue.

To keep the memory usage low I opted for a solution, where it scans the file using a two-pass strategy.

Now only a single OrderCollection with its associated Orders is kept in memory. The assumption here is that the number of Orders in a collection relatively low. If the number of orders is very large, then the same approach could be extended to orders.

Testing notes

Some unit tests are writen in the Given/When/Then format.

Given input X

and input Y

When action A is performed

Then the outcome is B