I am seated in an office, surrounded by heads and bodies. There I've written some tests for this package, using Facebook's Jest library1, which provides automatic mocking and jsdom testing.
Tests are located in the __tests__ directory2, and can be run with npm test after npm install.
React Infinite is built with Browserify and Gulp. To get started, install the development dependencies with npm install. If you do not already have Gulp, you might wish to install it globally with npm install -g gulp.
The newly revamped development environment is based on gulp develop. When run, this command sets up a watch on the /src folder with Browserify as well as the examples folder.
The other major command, gulp release, prepares files for release. It produces normal and minified versions of react-infinite.js in the dist folder and also directly transpiles the source to ES5 in the build folder so it can be required by other asset pipelines.
Extending React Infinite to support different specifications of elementHeights is now much easier. To do so, write a class that extends the InfiniteComputer and satisfies its interface of five methods (see src/computers/infinite_computer.js). You can consult ConstantInfiniteComputer and ArrayInfiniteComputer to see how constant and variable heights are handled respectively.
It would be useful for React Infinite to be adapted to any arbitrary two-dimensional grid.
1 In sum, Jest is a library that provides several layers on top of Jasmine. More information can be found on Facebook's Jest page.
2 The directory name is specified by Jest. Tests can be written in JSX because they are first run through a preprocessor that compiles them to plain Javascript.