function findTests(directory) {
    return shelljs.find(directory)
        .filter(filename => filename.endsWith(".src.js"))
        .map(filename => filename.slice(0, -".src.js".length)); // strip off ".src.js"
}
Find the test cases from a given directory.
Tests are the name of files that end with `.src.js`.
@param {string} directory The root directory to find.
@returns {string[]} The found test names.