02: Tools and Context

Submission Instructions

• Work in a fork of this repository
• Work in a branch on your fork
• Write all of your code in a directory named lab- + <your name> e.g. lab-susan
• Open a pull request to this repository
• Submit on canvas a question and observation, how long you spent, and a link to your pull request

Configuration

Configure the root of your repository with the following files and directories. Thoughtfully name and organize any additional configuration or module files.

• README.md - contains documentation
• .gitignore - contains a robust .gitignore file
• .eslintrc.json - contains the course linter configuration
• .eslintignore - contains the course linter ignore configuration
• package.json - contains npm package config
  • create a lint script for running eslint
  • create a test script for running tests
• lib/ - contains module definitions
• __test__/ - contains unit tests

Feature Tasks

fp Module

Create a NodeJS module in the lib/ directory named fp.js that exports an object. Create stand-alone map, filter, reduce, and slice functions using the call and apply function methods. Define each function using ES6 lexical arrow function syntax.

In each function error-check each parameter and throw an Error with a meaningful message if the function is invoked with invalid arguments. Do not use any third party libraries in the FP module.

• fp.map and fp.filter should have the function signature (callback, collection) => Array
• fp.reduce should have the function signature (callback, initialState, collection) => data
• fp.slice should have the function signature (begin, end, collection) => Array

Testing

FP Module Tests

Create a NodeJS module in the __test__/ named fp.test.js that asserts the correctness of the fp module.

• Use TDD describe and test methods to define descriptive tests
• Each test callback should aim to test a small well defined feature of a function
• Write tests to ensure the fp module functions correctly error-check parameters
  • Assert that the correct errors are thrown with invalid arguments
• Write tests to ensure the fp module functions returns the correct results when invoked with valid arguments

Documentation

In your README.md describe the exported values of each module you have defined. Every function description should include it's arity (expected number of parameters), the expected data for each parameters (data-type and limitations), and it's behavior (for both valid and invalid use). Feel free to write any additional information in your README.md.

Bonus 2pts

• Create a second module fp-curry.js that is a refactored version of fp.js, where each function has curried arguments
• Create a fp-curry.test.js that is a refactored version of fp.curry.js that tests fp-curry.js