The app is a visual tool designed to compare and highlight differences (aka diffing) in music lyrics. This is similar to plain text diffing, but is specifically geared at recognizing song text components and repeating patterns.

After cloning, launch from the public folder. Tested against PHP built-in server.

For the moment, the test suite covers the internals of the core diffing library. More unit tests are needed for diff providers and renderers. There's no functional test coverage yet.

The design of the app is intended to be demonstrative. Everything is written from the ground up combining components instead of relying on a single framework. The design is simplicistic but i tried to expose a number of concepts.

The diff algorithm is inspired by GNU's diff and the renderer used in the webapp implements GNU's wdiff basic idea. The algorithm is called after its creator, Douglas McIlroy. This implementation for PHP is partially ported from Tim Peters' implementation as found in the original difflib Python library.

The app uses the SideBySide renderer to output a diff-by-line, diff-by-word response. I tried to follow diffchecker.com/diff styling. More renderers are available, namely two Text renderers intended for console output. One works on lines (very much like the original diff) and the other on words (very much like the original wdiff).

Tests, tests, tests.