austriker27/04-bitmap

Lab 04: Bitmap Transformer

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

Resources

• Bitmap Specification
• Buffer Docs

Configuration

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

• README.md - contains documentation
• .gitignore - contains a robust .gitignore file
• .eslintrc.json - contains the course linter configuratoin
• .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__/assets/ - contains bitmaps for testing
• __test__/ - contains unit tests

Feature Tasks

For this assignment you will be building a bitmap (.bmp) transformer CLI. It will read a bitmap in from the hardrive(assets folder), run one or more color transforms and then write it out to a new file. This project will require the use of node buffers in order to manipulate binary data. Your solution should be composed of small tested modules that solve specific problems. Your modules should be thoughtfully named and well documented. The entry point to your CLI should be an index.js file in the root of your package, and all helper modules should be placed in your lib/ directory. Your bitmap transformer modules should not use any third party libraries.

Minimum Requirements

• The CLI should be architected using best modularization practices
• The CLI should require at least three arguments input-file-path output-file-path transfrom-name
• The CLI should support a minimum of three transforms
• The CLI should log useful Error messages if used incorrectly
• The CLI should log a success message on completion

Testing

• Use TDD describe and test methods to define descriptive tests and increase readablity
• Each test callback should aim to test a small well defined feature of a function
• Write tests to ensure each function behaves correctly with valid and invalid inputs
• The CLI should be tested without using child_process or any equivilant third party libraries

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 paramiters), the expected data for each parameter (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.

Tips

You will want to define a strategy for solving the problem before you begin to code. Once you have a strategy defined, you can break it down into steps that can be split into helper modules. Each helper module should solve a small specific problem. The main module should utilize the helper modules to execute your original strategy.

Example Strategy

0. Gather user input (infile, outfile, and transform)
1. Read the input bitmap file using the fs module
2. Parse the bitmap's buffer into object representing a bitmap (using a constructor)
3. Using metadata from the parsed bitmap object to run a transform on the buffer directly (mutate the colors)
4. Write the mutated buffer to the output file path

Transfrom Ideas

• Color Palette Transforms
  • Invert
  • Randomize
  • Greyscale
  • Black and White
  • Darken or Lighten
  • Add or Mutiply a Hue
  • Add or Subtract Contrast